DOI: 10.3897/sjp.145.211690

Authors: Chuanshang Wang, Jörg Maletz, Xiaofeng Wang

Abstract: The uppermost Aeronian (Llandovery, Lower Silurian) Stimulograptus sedgwickii Biozone, as found in the Guluoping section, Hubei Province, China, and its correlation are discussed. This interval has rarely been recognized in China. The differentiation into the Stimulograptus sedgwickii Biozone and the Stimulograptus halli Biozone, recognized in several regions, is problematic and thus is not used in South China. Stimulograptus sedgwickii, Lituigraptus urceolus, and Parapetalolithus praecedens are among the most common and indicative species for the biostratigraphic interval in the Guluoping section. The graptolite fauna can be referred to the higher part of the Stimulograptus sedgwickii Biozone, but not to the top of the interval. A moderately diverse fauna of biserial and uniserial (monograptid) axonophoran graptolites is described and illustrated. The graptolites are associated with a number of small, possibly lyssacinosidan hexactinellid sponges (?Rossellidae) and remains of indeterminate phosphatic brachiopods. The tectonic deformation makes some graptolite identifications difficult, but new taxa have not been noted.

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DOI: 10.3897/sjp.145.199515

Authors: Yuichiro Nishioka, Yusuke Ando

Abstract: A fossil deer skeleton, including cranial appendages, of an intermediate-aged individual, as indicated by the wear stage of the M3/m3, was newly discovered from the Lower Miocene Togari Member (ca. 18 Ma) of the Akeyo Formation, Mizunami Group in central Japan and classified as a new species of Procervulus (Cervidae, Artiodactyla, Mammalia), P. mizunami sp. nov. Procervulus mizunami shares several features with basal stem cervids from Europe, such as Procervulus, Heteroprox and Acteocemas, notably dichotomous antlers and distinct internal postprotocristae on the upper molars. The frontal appendages of P. mizunami are more similar to those of Procervulus than to those of Heteroprox or Acteocemas, in that the antlers lack derived apomorphic features around the antler base, such as the basal thickening and accessory structures. It resembles P. dichotomus in pedicle diameter and tooth size, but differs in having a proportionally wider antler base and a shorter pedicle. The frontal appendages of P. mizunami are also similar to those of P. praelucidus, but P. mizunami has larger teeth and a larger pedicle diameter than the latter. The unusually short pedicle is diagnostic of P. mizunami and distinguishes it from all other known species of Procervulus. The postcranial bones of P. mizunami are fundamentally similar to those of P. dichotomus, although the metacarpal is proportionally much shorter than the metatarsal in the former. Basal cervids bearing dichotomous antlers are well documented from the Lower Miocene of Europe, but have not previously been recorded from contemporaneous localities in Asia. The discovery of P. mizunami provides the first evidence that one of the earliest cervids with dichotomous antlers had dispersed into East Asia by ca. 18 Ma. The plesiomorphic characteristics found in the remains of P. mizunami suggest that the earliest cervids rapidly dispersed throughout Eurasia.

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DOI: 10.3897/sjp.145.198907

Authors: Shilin Hou, Chang-Fu Zhou, Hongyu Yi

Abstract: Tail shedding is a widespread anti-predator strategy in modern lizards, facilitated by specialized autotomic structures in the caudal vertebrae. These structures include a fracture plane and, in some taxa, a pseudospine that creates predetermined breaking points along the tail. In caudal vertebrae, the position of the fracture plane relative to the transverse processes varies among extant squamates and has been used as a phylogenetic character. However, little is known about the three-dimensional morphology of autotomic structures in extinct lizards, particularly in early taxa from the Jurassic and Cretaceous Lagerstätten that are preserved in compressed slabs with limited exposure of the fracture plane. Using high-resolution X-ray computed tomography (CT), we examined the caudal vertebrae of two Early Cretaceous lizards from the Jehol Lagerstätten of China: Yabeinosaurus sp. and Dalinghosaurus longidigitus. Our CT reconstructions reveal that both taxa possess fracture planes, but with distinct morphologies. In Yabeinosaurus, the fracture plane traverses directly through the transverse processes, partitioning them into anterior and posterior segments, a condition present in certain species of extant Scincinae, Xantusiidae, Anguidae, and Shinisauridae. In Dalinghosaurus, the fracture plane lies posterior to the transverse processes, resembling the condition in extant gekkotans, lacertids and some iguanians. Additionally, Dalinghosaurus exhibits a fan-shaped pseudospine encompassing the fracture plane – a structure previously unrecognized in this genus – and shows partial fusion of the fracture plane, implying that autotomic capability may have varied through ontogeny. These findings demonstrate that fracture plane morphology was already disparate among Early Cretaceous squamates. High-resolution CT imaging of compressed fossils provides a powerful tool for resolving the three-dimensional anatomy of autotomic structures, enabling more robust morphological comparisons and providing novel characters for future phylogenetic analyses.

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DOI: 10.3897/sjp.145.210382

Authors: Zhiheng Ma, Yunke Zheng, Maxwell Wang, James C. Lamsdell, Jiashu Wang, Long Pang, Liurunxuan Chen, Paul A. Selden, Yongsheng Yuan, Jie Zeng, Ben He, Xinrui Hu

Abstract: A recently recovered slab of siltstone preserving two individuals of Malongia mirabilis Wang et al., 2022 is described from the Early Devonian Xitun Formation in Yunnan Province, south-western China. This material reveals a suite of morphological features that were not documented in the original description of the species. Using these newly-recognised morphological characters, we revise the morphological character matrix and re-assess the phylogenetic affinity of M. mirabilis. Our phylogenetic analyses reveal that Malongia occurs in a polytomy with Dolichopterus and the clade comprising Ruedemannipterus and Clarkeipterus. The new material, therefore, improves our knowledge of the morphology of this poorly known Chinese dolichopterid and provides new evidence for evaluating the evolutionary history of Dolichopteridae on the South China Block.

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DOI: 10.3897/sjp.145.211471

Authors: Chien-Hsiang Lin, Siao-Man Wu, Hsin-Wei Liu, Chia-Hsin Hsu

Abstract: Otolith paleontology traditionally relies on descriptive alpha taxonomy and standard ecological inference, leaving some aspects of long-term community restructuring insufficiently explored. Here we apply a quantitative community framework integrating formal beta diversity partitioning, which separates species turnover from nestedness, and multivariate dispersion analyses to evaluate Neogene–Quaternary teleost dynamics in the western Pacific. Based on 4,893 newly collected otoliths along the Dahan River section in northern Taiwan, the dataset completes an 8-million-year sequence extending from the Late Miocene into the Quaternary. Multivariate analyses resolve three distinct, epoch-defined assemblages: Miocene, Pliocene, and Pleistocene. Moreover, otolith-based community restructuring across temporal transitions was driven by taxonomic turnover that suggests gradual faunal replacement rather than simple diversity loss or nestedness-driven assemblage contraction. At the regional scale, we compiled 5,083 sciaenid otolith occurrences from the western Pacific, revealing a transition from Late Miocene endemic shelf taxa to Plio–Pleistocene assemblages increasingly dominated by extant lineages. Finally, this sciaenid otolith record exposes discrepancies with molecular-clock hypotheses that infer older divergence times for several modern lineages whose fossil appearances currently date to the Plio–Pleistocene. Our study demonstrates how fossil otoliths can be used to link local paleoecological signals with regional community turnover, providing empirical constraints for molecular phylogenies and contributing to a better-resolved view of teleost evolution in the western Pacific.

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DOI: 10.3897/sjp.145.207461

Authors: Mengxi Han, Menghan Duan, Jingyao Song, Mingze Hao, Yujie Liu, Shuai Shao, Kohta Kubo, Yang Li, Qian Wu, Paul Rummy, Shiying Wang

Abstract: The evolution of the pedal morphology and the ontogeny of early oviraptorosaur theropods remain inadequately understood, largely owing to the poor preservation of available material and the limitations of traditional observation methods. Here, we describe a particularly well-preserved and nearly complete pedal specimen (PMOL-AD00126) from the Lower Cretaceous Jehol Group of western Liaoning, P.R. China and assign it to Caudipteridae, an early-diverging clade of oviraptorosaurs. Three-dimensional reconstruction of the pes reveals numerous previously undocumented morphological features, including a subarctometatarsalian metatarsus, metatarsal I with pronounced dorsal and plantar prominences, distinct plantar ridges on metatarsals II and III, an elongated extensor ligament pit on metatarsal III and well-developed extensor ligament pits and articular ridges on the pedal phalanges. Histological analysis indicates that this individual had not attained complete somatic maturity. These newly-recognised morphological and histological characters provide significant insights not only into the taxonomy and ontogeny of Caudipteridae, but also into the evolution of early oviraptorosaurs.

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DOI: 10.3897/sjp.145.200204

Authors: Gerald Mayr, Thomas Lechner, Madelaine Böhme

Abstract: We report bird fossils from the early Late Miocene (earliest Tortonian) of the Hammerschmiede clay pit in southern Germany. The material includes a stem group representative of the Phalacrocoracidae, which is described as Bavaricarbo brevirostris gen. et sp. nov. as well as another, unnamed and much smaller cormorant species the size of extant Microcarbo species. Furthermore, we identified new material of the darter Anhinga pannonica (Anhingidae), including the first (partial) tarsometatarsus of the species, and a fragmentary humerus belonging to an undetermined species of the Gaviiformes. A partial tarsometatarsus of an unusual accipitriform bird is described as Mioaetus pforzenensis gen. et sp. nov. A humerus represents one of the earliest records of the apodiform Apodi and is tentatively assigned to Apus gaillardi. The avifauna from the Hammerschmiede clay pit stems from a time interval of the Miocene that yielded comparatively few avian remains in Europe, and the site continues to produce taxa that have not yet been reported from other Miocene localities. The coexistence of at least two cormorant species, a darter, and a gaviiform testifies to the high productivity of the river system that existed at the site, which must have provided ample prey for piscivorous birds.

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DOI: 10.3897/sjp.145.196379

Authors: Dongxiang Yu, Honggang Zhang, Chang-Fu Zhou, Rui Pei

Abstract: A new, well-preserved troodontid postcranial skeleton from the Jehol Biota of the Ningcheng Basin, Inner Mongolia, China, is described and assigned to Sinovenator changii based on an autapomorphy: the presence of two pneumatic foramina on the lateral surface of the anterior cervical vertebrae. This specimen is inferred to be an adult based on the presence of an external fundamental system (EFS) in the ulna, as well as the complete fusion of the cervical neural arches and centra. This represents the first record of a troodontid dinosaur from the Jehol Biota in Inner Mongolia. The discovery of this new specimen reveals additional morphological details of Sinovenator changii and expands the paleogeographic range of this taxon. Notably, this new specimen bears a moderately developed pubic ambiens process, in contrast to the anteroposteriorly elongated condition in Late Cretaceous troodontids. This morphology may reflect an early evolutionary phase in the elongation of the ambiens process among troodontids and might suggest a comparatively constrained hindlimb locomotor capacity relative to that of their Late Cretaceous relatives. In addition, body size comparisons among deinonychosaurians reveal that dromaeosaurids exhibit much greater size disparity than troodontids, which may reflect greater diversity in dromaeosaurid locomotion, ecological niches, or growth strategies.

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DOI: 10.3897/sjp.145.193019

Authors: Laia Garcia-Escolà, Jordi Marcé-Nogué, Ane de Celis, Núria Cuadrado, Eduard Vidales, Penélope Cruzado-Caballero, Alejandro Serrano-Martínez, Carolina Castillo-Ruiz, Josep Fortuny

Abstract: Computational approaches are increasingly used to study the relationship between form and function in extinct and living organisms. However, one major challenge remains: assumptions about bone material properties, especially when studying fossils. In this work, direct mechanical testing and computer-based modelling are combined to assess cranial bone stiffness in the lizard genus Gallotia, endemic to the Canary Islands (Spain), including extinct species. Using linear mixed models, bone stiffness was found to be uniform across skull regions, with a trend towards lower stiffness in larger species. Simulations of biting loads showed that differences in bone properties had a limited influence on mechanical performance, supporting the use of average values in functional models. Using this framework, bone stiffness in extinct Gallotia giants was estimated, and its significance was explored. The results suggest a link between skull flexibility, body size, and diet, offering a practical approach to reconstructing biomechanical traits in extinct vertebrates across evolutionary timescales.

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DOI: 10.3897/sjp.145.198341

Authors: Tomasz Szczygielski, Fanny Celestin, Sylvain Adnet, Guillaume Guinot

Abstract: The earliest turtles (clade Testudinata) are known from the Norian (middle Late Triassic) and soon after their appearance they became speciose and widespread. However, their record in the later part of the Late Triassic (Rhaetian) remains very scarce. Herein, we present the first European representatives of the clade from that age. Bartassochersis lopezi gen. et sp. nov. from the Rhaetian Formation of France is recovered here as a proterochersid and presents a number of unique, autapomorphic characters, hinting at the previously unknown morphological diversity of stem turtles in the latest Triassic. This landscape is supplemented by a find of an indeterminate, but probably remarkably small-bodied species from the ‘Grès infraliasiques’ Formation. Previously uncharted regions and latest Triassic strata of Pangaea may, therefore, still hide unknown testudinates.

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DOI: 10.3897/sjp.145.203557

Authors: Rok Gašparič, Oleksandr Kovalchuk, Martin Mazuch, Martin Košťák, Tomaž Hitij, Martina Kočová Veselská, Tomáš Kočí, Zoltán Barkaszi

Abstract: A bromalitic concentration from the Lower Miocene (upper Burdigalian, calcareous nannoplankton Zone NN4) deposits of Meljski Hrib near Maribor, northeastern Slovenia, preserves at least 25 fragmentary basking shark gill rakers together with polygonal calcified-cartilage tesserae and disarticulated echinoid remains. Comparative morphology, geometric morphometric analysis of gill-raker bases, and micro-computed tomography of associated skeletal elements support assignment of the material to Keasius cf. K. septemtrionalis. This represents the first confirmed occurrence of Keasius from Slovenia and extends the known paleogeographic distribution of the genus into the southeastern margin of the Central Paratethys. The close association of cetorhinid remains with abundant echinoid material and the absence of acid etching on gill-raker surfaces indicate that the assemblage is rather a regurgitalite than a coprolite. The associated invertebrate fauna indicates deposition in an outer-shelf to upper-slope environment (approximately 150–250 m water depth). This taphonomic and paleoenvironmental context is most consistent with opportunistic scavenging by a benthopelagic vertebrate predator, plausibly a lamniform or hexanchid shark. The assemblage provides rare fossil evidence of trophic interactions involving planktivorous basking sharks and macrophagous vertebrates in Miocene deep-water ecosystems and provides new insights into the paleoecology and biogeographic history of cetorhinid sharks within the Paratethyan realm.

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DOI: 10.3897/sjp.145.195625

Authors: Ya-Lei Yin, Bu-Yu Wu, Rui Pei, Hong-Gang Zhang, Xin Zhang, Feng-Bin Shen, Xu Xing

Abstract: The anatomical characteristics of troodontid teeth have remained largely unexplored. This study employs high-resolution computed tomography data to reconstruct and describe the morphology of two troodontid teeth, one newly discovered complete specimen and one previously documented specimen, from the Upper Cretaceous Yuliangzi Formation, located in the Sunwu–Jiayin Basin in Jiayin, Heilongjiang, northeastern China. The reconstruction reveals previously unrecognized anatomical features and presents the first three-dimensional visualization of the pulp cavity of troodontid teeth. Notably, the ratio of enamel thickness at the base of the crown to crown height is 0.19%. The enamel thickness on the labial side exceeds that on the lingual side in the mesial and distal denticles, a phenomenon observed for the first time in theropod teeth. The pulp cavity is distinctly narrow in the labiolingual dimension, tapers sharply toward the apex, and exhibits a distal curvature. It also displays nine distinct projections along the basal half of its distal margin. A wear facet is present, exhibiting an elliptical shape with parallel wear striations. Comparative morphological analysis identifies the new specimen as a Troodon-morphotype tooth, thereby providing further evidence for faunal exchange between North America and Asia via Cretaceous Beringia. Moreover, the only theropods that have been definitively identified from the Yuliangzi Formation are tyrannosaurids and troodontids. In addition, comparison of various dinosaur faunal assemblages within Maastrichtian deposits in China indicates that all of them contain tyrannosaurids.

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DOI: 10.3897/sjp.145.188479

Authors: Shengguang Chen, Dezhi Wang, Zhixin Sun, Zhengpeng Chen, Xinglian Yang, Fangchen Zhao

Abstract: The exceptional fossil record of trilobite ontogeny allows the elucidation of the developmental evolution of early arthropods. However, the paucity of detailed segmental growth data limits the understanding of growth dynamics during post-embryonic development. Rich trilobite material is preserved in the Cambrian Kaili Biota (Miaolingian Series, Wuliuan Stage), and many articulated specimens of the “ptychopariid” Kaotaia globosa Chang & Zhou in Lu et al., 1974, from a relatively narrow stratigraphic interval provide valuable opportunities for a detailed ontogenetic study. This study documents the ontogenetic sequence and phenotypic changes of K. globosa from meraspid degree 3 to the holaspid period, integrating traditional morphological descriptions and geometric morphometric analyses. Analyses revealed that the primary changes in the K. globosa cranidium during ontogeny occurred in the glabella, facial suture, and palpebral lobes. The trunk of K. globosa follows a hemianamorphic pattern with a protomeric developmental mode. Growth model fitting suggests that the trunk-segment growth rate of K. globosa is controlled by a growth field (TGmold), which exhibits a continuously increasing growth gradient from front to back. A comprehensive analysis of existing data revealed significant variation in holaspid exoskeletal length, suggesting that an increasing growth gradient may have enabled these trilobites to undergo shorter anamorphic development followed by prolonged epimorphic development for body-size increase.

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DOI: 10.3897/sjp.145.188227

Authors: Juan D. Daza, Emily G. Stelling, Kelsey M. Jenkins, Edward L. Stanley, Daniel S. Doucet, Gabriela Fontanarrosa, Aaron M. Bauer

Abstract: Palaeontologists use skeletal features to determine the sex of specimens, but this can be complicated due to the incompleteness of fossil remains. In fossil assemblages, sexual dimorphism may be present in the form of ornamentation or may occasionally be detected through multivariate analyses. Sex can sometimes be estimated when embryos or eggs are found within a female specimen or associated with the specimen (e.g. brooding behaviour), although other sex-specific traits are rarely preserved in fossils. Squamates exhibit hemipenal bulges that are externally observable in males. These structures typically do not leave traces in hard rock fossils, but may be preserved in amber. We describe two lizard specimens embedded in burmite amber, which preserve almost the entire integument, though skeletal remains are very incomplete. One specimen shows a swelling at the base of the tail, comparable to the hemipenal bulge in male squamates, suggesting the presence of paired copulatory organs or hemipenes. Hemipenes almost certainly originated in the ancestor of Squamata or in stem-Squamates during the Triassic Period and this fossil provides rare documentation of these structures in the mid-Cretaceous. Research on amber fossils continues to highlight the remarkable preservation of soft tissues, even when hard tissues are poorly preserved. In this paper, we followed high ethical standards for sourcing these controversial fossils, following the recommendations from the Myanmar working group of the Society of Vertebrate Paleontology.

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DOI: 10.3897/sjp.145.193008

Authors: Martin Ebert

Abstract: The pycnodontiform family Mesturidae from the Middle and Upper Jurassic of central Europe has been studied in detail. Mesturus verrucosus, the type species of the genus Mesturus, is being re-described, primarily based on new, partly juvenile specimens. M. verrucosus is recognised as the only species of the genus Mesturus. The species previously described under Mesturus, M. leedsi, is now described as new genus Aminiichthys. Additionally, specimens which until now were added to the type species Mesturus verrucosus were now separated from this taxon and placed in the separate new genus Goodichthys. The new genera Aminiichthys and Goodichthys differ from the genus Mesturus mainly in the scale rows of the body which do not bifurcate, the ornamentation of vomer and prearticular teeth and for Goodichthys also in the lower number of dorsal fin rays and the elongated scales in the cheek region. New small specimens of 4–9 cm total length from Eichstätt and Painten were assigned here to Mesturus verrucosus for the first time and described as juveniles using newly-taken UV photos that reveal many previously unknown features. A new phylogeny of the Pycnodontiformes is presented, in which the new taxa were added.

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DOI: 10.3897/sjp.145.185485

Authors: Zechuan Zhang, Qixing Dong, Tao Wang, Hailu You, Xunlian Wang

Abstract: Panguraptor lufengensis You et al., 2014 is the first Coelophysoidea species that has been named in Asia. In previous studies, the description of the holotype lacked anatomical detail, providing insufficient information. In this research paper, the anatomy is further described, and the autapomorphic characters of P. lufengensis are re-evaluated, resulting in a diagnosis comprising six characters. Phylogenetic analysis shows that P. lufengensis is an early-branching member of the superfamily Coelophysoidea, indicating a yet to be uncovered ghost lineage of Coelophysoidea in East Asia.

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DOI: 10.3897/sjp.145.195025

Authors: Z. Jack Tseng

Abstract: Leptarctine mustelids are Neogene carnivorans with fossil records in Asia and North America. In the 170 years since the clade was erected, all taxa within this clade have been characterised based on craniodental traits. Despite having geographically extensive and well-preserved fossil records, no postcranial elements of leptarctines are known other than a single atlas and axis reported from Inner Mongolia. Here, I describe a partial skeleton of Leptarctus wortmani, with associated lower dentition, partial cranium and partial postcranial elements representing fore-limb, hind-limb and pre-sacral vertebral column. I conduct a functional morphological analysis of the external proportions and internal epiphyseal trabeculae of limb elements to provide information for the locomotor mode of Leptarctus. Functional indices of external limb morphology and internal trabeculae both indicate that L. wortmani was likely a generalist in its locomotor mode; there is no support for an arboreal lifestyle as previously suggested, based on dental similarities to kinkajou or koala. Overall, the postcranial morphology of L. wortmani most closely resembles that of extant Eurasian badgers Meles, albeit with reduced ungual phalanges and more elongate long bones for its size. These palaeoecological inferences suggest that L. wortmani occupied a badger-like niche during the middle and late Miocene, pre-empting the appearance of true North American badgers, such as Pliotaxidea and Taxidea. Competitive replacement by extant badgers may be responsible for the extinction of leptarctines by the Pliocene.

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DOI: 10.3897/sjp.145.191327

Authors: Nicolas Wagner, Johannes Horn, Johannes von Kleist, Quentin Martinez, Gabriel S. Ferreira, Eli Amson

Abstract: Pachyostosis, the increase in volume of bones, has been documented in a myriad of tetrapods that secondarily adapted to the aquatic environment. However, this convergent trait has hitherto only been quantified in complete ribs and long bones. This study presents a methodology designed to quantify the degree of pachyostosis in ribs and vertebrae for both complete and fragmentary skeletal elements. Using surface models, the volumes of costal and vertebral regions were measured and standardized using size proxies to devise a pachyostosis index. Sirenians are used as a case study, given the disparity in pachyostosis degrees that has already been documented in the clade, especially in their ribs. The new methodology can detect this disparity and further demonstrates that pachyostosis also affects their vertebrae. Milder cases of pachyostosis, such as in the extant Dugong dugon, are likely secondary specializations to a specific lifestyle. The craniocaudal distribution of the pachyostosis index values is also potentially helpful for further distinguishing finer lifestyle differences. This new method has the potential to clarify the causes of the disparity in pachyostosis degrees observed in the fossil record of sirenians, and it may also prove valuable in broader, non-mammalian contexts.

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DOI: 10.3897/sjp.145.193722

Authors: Amane Tajika, Peter Kürsteiner, Karl Tschanz

Abstract: Over the past decade, a large number of macrofossils have been documented from the Alpstein Region (north-eastern Switzerland), shedding light on the local diversity and palaeoecology during the Early to Late Cretaceous. Although ectocochleate cephalopods exhibit some of the highest diversity and abundance within this fauna, only a few nautilid genera have been documented thus far. Here, we report a new occurrence of the Cretaceous nautilid Pseudocenoceras archiacianum. To the best of our knowledge, this is the first record of the genus Pseudocenoceras from Switzerland. Additionally, this represents the first occurrence of P. archiacianum from the Albian stage. However, because early taxonomic works often underestimated the impact of ontogenetic and intraspecific variation, a comprehensive revision of the taxonomy and systematics of nautilids is needed.

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DOI: 10.3897/sjp.145.189487

Authors: Walter G. Joyce, Léa C. Girard, Tyler R. Lyson

Abstract: The pan-trionychids Aspideretes beecheri and Helopanoplia distincta were named at the beginning of the 20th century based on fossils collected from the Late Cretaceous (Maastrichtian) Lance Formation of Wyoming. Interestingly, even though numerous additional pan-trionychid remains from Late Cretaceous formations of the Upper Great Plains have since been referred to Helopanoplia distincta based on its unique surface texture, no additional specimens have been referred to Aspideretes beecheri. We figure and describe all material previously referred to Aspideretes beecheri and select specimens referred to Helopanoplia distincta. Interspecific and intraspecific variation is assessed by reference to extant trionychids as a basis for taxonomic revision. We re-assign all specimens historically referred to Aspideretes beecheri to Axestemys splendidus and Axestemys infernalis. An unusual plastron previously thought to represent Helopanoplia distincta is referred to Hutchemys walkerorum. Although the type of Helopanoplia distincta is characterized by a distinct, tuberculate shell surface texture, material previously referred to this taxon suggests that this texture is only occasionally found in some parts of the shell. The holotype of Aspideretes beecheri otherwise shows characteristics consistent with being the subadult of material previously referred to Helopanoplia distincta. We thus conclude that the two taxa are synonymous and form the new combination Helopanoplia beecheri. We urge caution when identifying fragmentary pan-trionychid remains, as a tuberculate surface texture pattern is found in at least two distinct taxa. We support the conclusion, nonetheless, that Helopanoplia beecheri is one of only a few turtles to have gone extinct at the Cretaceous–Paleogene boundary.

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DOI: 10.3897/sjp.145.186528

Authors: Wojciech Pawlak, Adam Rytel, Jorge Domingo Carrillo-Briceño, Ursina Bachmann, Ben Pabst

Abstract: Lungfishes are common components of the Late Triassic, continental vertebrate assemblages, and yet remain understudied compared to their frequency. They are represented by the three genera, most abundant in specimens: Arganodus, Ceratodus and Ptychoceratodus. Here, we describe new Ptychoceratodus lungfish material from the Late Triassic Klettgau Formation of Switzerland, which is known for its occurrences of numerous synapsids, sphenodonts, turtles, and dinosaurs. The provided description of lungfish dental plates is the first from this formation, despite brief earlier reports. Besides the description of new material, we re-evaluate the studies of lungfish from Late Triassic north-western Pangea and their palaeogeographic distribution. Our results illuminate the potential controls on the distribution of the three most common genera of that time. Our results support the hypothesis that the distribution of Arganodus and Ptychoceratodus followed the latitudinal belts, controlled either by climatic conditions or hypothetical physical barriers. The distribution of Ceratodus appears to be associated with the coastal regions of the continent, although no direct evidence indicates its tolerance for marine salinity. The study is strengthened by the first georeferenced, open-source dataset of fossil lungfish occurrences used for the abovementioned analysis. The dataset can be readily expanded with data from other stratigraphic and spatial frameworks, acting as a foundation for future, fully reproducible palaeobiogeographic studies.

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DOI: 10.3897/sjp.145.189856

Authors: Damien Becker, Manhon Mouhat Bourquard, Olivier Maridet, Davit Vasilyan

Abstract: Three fossiliferous horizons of the Late Pliocene (MN15–early MN16) locality of Jradzor in Armenia have yielded numerous well-preserved dental and postcranial remains of Hipparionini. Based on anatomical comparisons and allometric analyses, all described specimens are attributed to “Hipparion” longipes. The systematics of this species remains unclear. Following detailed morphological observations and morphometric analyses of Pliocene Hipparionini, this study suggests a re-assignment of both “Hipparion” longipes and “H.” fissurae to the genus Cremohipparion (comb. nov.). Furthermore, the large, slender-limbed Cremohipparion sp. from Ruscinian localities on the Iberian Peninsula (La Gloria 4, La Calera, Orrios-1 and Villalba Alta Rio 1) is, as suggested in recent literature, morphologically distinct from Cremohipparion fissurae from its type locality in Layna and is likely endemic to Spain during MN14. The tentative revision of “H.” cf. longipes from Akkaşdağı (MN13, Turkey) into Cr. cf. fissurae, in addition to the confirmed record of Cr. fissurae in Layna (MN15, Spain), leads a reconsideration of both the palaeobiogeographic distribution and biostratigraphic range of this species.

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DOI: 10.3897/sjp.145.182523

Authors: Francisco J. Serrano, M. Patrocinio Espigares, Guillermo Rodríguez-Gómez, Bienvenido Martínez-Navarro, Sergio Ros-Montoya, Javier C. Terol, Óscar Sanisidro, Antonio Guerra-Merchán, José Manuel García-Aguilar, Isidoro Campaña, Alejandro Granados, Paul Palmqvist

Abstract: The fossil site of Venta Micena (Baza Basin, southeastern Iberian Peninsula), dated to the Early Pleistocene (1.6–1.5 Ma), is renowned for its huge assemblage of skeletal remains of large mammals, most of which were unburied from two roughly coeval excavation quarries, VM3 and VM4. These bone accumulations resulted from the scavenging habits of giant hyaenas (Pachycrocuta brevirostris), which transported ungulate carcasses to their maternity dens to consume them. The fossils have enabled detailed reconstructions of Western European faunal communities during the Early Pleistocene, but the remains of small vertebrates, particularly birds, are rare and still poorly understood. Here we describe the first avian remains from Venta Micena and assess their palaeoenvironmental and ecological significance. Three taxa were identified: (i) the Common Shelduck Tadorna tadorna; (ii) the Pleistocene Giant Crane Grus cf. primigenia; and (iii) the Pleistocene subspecies of Common Raven, Corvus corax antecorax. The presence of T. tadorna and G. cf. primigenia suggests the existence of a wetland environment characterized by oligohaline waters surrounded by brackish pools in the vicinity of the site. The presence of C. corax antecorax is consistent with the abundance of remains of ungulate carcasses exploited by P. brevirostris, indicating rich scavenging opportunities. Palaeosynecological modeling suggests that meat consumption by ravens approached those of each of the large carnivores, thus significantly reducing the available carrion for other secondary consumers. Moreover, digestive corrosion and tooth marks on bird bones evidence the consumption of avian remains by carnivores, probably juvenile hyaenas. Altogether, these findings reveal a more complex structure of the faunal community that inhabited Venta Micena than previously recognized. First avian remains from Venta Micena are described, including a shelduck, Tadorna tadorna, and the oldest records of the large crane Grus cf. primigenia and raven Corvus corax antecorax. Grus and Tadorna support the presence of a mild, oligohaline to brackish wetland environment in the Baza Basin. The scavenging habits of Corvus add complexity to the trophic interactions in the ecosystem surrounding the Baza palaeolake.

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DOI: 10.3897/sjp.145.180311

Authors: Saverio Bartolini-Lucenti, Joan Madurell‑Malapeira, Adrian Marciszak, Marie Meyer, Damien Becker, Davit Vasilyan

Abstract: The Jradzor locality (Armenia, South Caucasus) provides a stratigraphically constrained Pliocene carnivoran record spanning 4.16–3.98 Ma and 3.3 ± 0.03 Ma. Here we report new material of five taxa: Nyctereutes urartuensis, Chasmaporthetes lunensis and Pliocrocuta perrieri from the horizon JZ–7, Baranogale helbingi, and a lynx-sized felid from three older layers (JZ–3s, JZ–13 and JZ–15). Dental and mandibular morphology, together with morphometric analyses, indicate a guild combining an omnivorous raccoon dog, an archaic ictonychid mustelid and two large hyaenids representing distinct feeding strategies (cursorial hunting vs. bone cracking). The Jradzor assemblage documents carnivoran diversity and ecological structure at the biogeographic junction between Europe and Asia especially along the southern margin of the Eastern Paratethys and contributes to understanding dispersal and community dynamics during the Pliocene.

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DOI: 10.3897/sjp.145.182210

Authors: Evangelos Vlachos, Davit Vasilyan

Abstract: The origin of the Testudo graeca complex has been suggested to be in the Caucasus. Poor fossil records and incomplete preservation of available fossils limit deep-time reconstructions of the paleobiogeographic history of the complex. The present work describes recently discovered tortoise species found from the Early Pliocene Jradzor site, Armenia. Apart from being one of the few well-preserved and complete species of the genus in the fossil record, the Jradzor species is the only well-dated (∼4.16 and 3.98 Ma) form among fossil representatives of the genus. The tortoise material is numerous and comprises several complete and partial shells, including some rare cranial elements and numerous postcranial bones, including the presence of bony thigh spurs. The material clearly belongs to a testudinid taxon, based on the alternating neural plates, the coincidence between the costal/peripheral sutures and the pleural/marginal sulci, the presence of a well-developed epiplastral lip, and the complete fusion of the trochanters of the femur, reaching an average carapace length of 30 cm. Furthermore, the presence of a clear hypo-xiphiplastral hinge on the plastron indicates that the Jradzor tortoise is a member of the true Testudo (or sensu stricto) lineage. Our morphological and phylogenetic analysis placed the Jradzor tortoise within the context of the Eurasian Testudinini, showing that the recovered material should be described as a new species, that is phylogenetically placed as a sister group to the extant Testudo graeca complex. The new material allows an evaluation of the validity of previously known and relevant taxa and their inclusion in a new phylogenetic analysis like Testudo eldarica and Testudo kuchurganica, excluding Testudo burtsсhaki that should be considered as a nomen dubium. The new material presented herein sheds light on the origin and early evolution of the modern Mediterranean tortoises.

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DOI: 10.3897/sjp.145.179243

Authors: Yuehui Yan, Wenjin Zhao, Yanchao Luo, Hanxin Yu, Min Zhu

Abstract: Bothriolepis yunnanensis Liu, 1962, was first described based on an anterior median dorsal plate (assigned here as the lectotype) and a posterior median dorsal plate (assigned here as the paralectotype) from the Shangshuanghe Formation (Eifelian, Middle Devonian) in Qujing, Yunnan, southwestern China. Since then, no additional material has been assigned to B. yunnanensis, resulting in its morphology and phylogeny being poorly understood. In this study, we provide a comprehensive description of the head shield, trunk armor, and pectoral appendage of B. yunnanensis based on newly collected specimens from the type locality and neighboring sites in the Zhujiangyuan (Pearl River Source) area, Qujing. With the new fossil horizon in the Xichong Formation (Givetian), our latest findings extend the temporal range of B. yunnanensis to the entire Middle Devonian. Phylogenetic analysis shows that B. yunnanensis, B. zhujiangyuanensis, B. sinensis, and B. kwangtungensis from China and some Bothriolepis species from Laurussia and Kazakhstania are united into a clade sharing a slender proximal segment of the pectoral appendage, the absence of the median occipital crista, and a long posterior pit line. This result further corroborates the paleogeographic proximity between the South China and Kazakhstania blocks.

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DOI: 10.3897/sjp.145.192061

Authors: Javiera Roco-Villablanca, Marcelo M. Rivadeneira, Sven N. Nielsen

Abstract: Scaphopods (Class Scaphopoda, Phylum Mollusca), commonly known as tusk shells, are univalve mollusks exclusively from marine environments that live buried within the substrate. Within this class there are two orders: Dentaliida (elongated shells with sculpture and ornamentation) and Gadilida (smaller, smooth shells). For the Miocene marine deposits (Burdigalian) of the Navidad Formation, Ranquil Formation, Lacui Formation and Ipún beds, the diagnostic characters of a total of 2,103 scaphopod specimens were studied in order to identify and define species, and to establish biogeographical patterns within the latitudinal transect from 33°S to 45°S, through the evaluation of the alpha, beta, gamma biodiversity and rarefaction indices. Eleven species of Scaphopoda were identified for the Lower Miocene of Chile. Of these species, seven belong to the order Dentaliida (Dentalium sulcosum, Fissidentalium majus, Fissidentalium matanzasense comb. nov., Fissidentalium subgiganteum, Fissidentalium taverai sp. nov., Fissidentalium sp. 1, and Fissidentalium sp. 2) and four to the order Gadilida (Gadila philippiana comb. nov., Cadulus scarabinorum sp. nov., Polyschides pichi sp. nov., and Dischides nor sp. nov.), being the first Miocene gadilid species recognized from Chile. With the existing paleobathymetric information based on otolith associations, it was possible to determine the environment of the most abundant species of Scaphopoda from the Lower Miocene of Chile. The most abundant species are Gadila philippiana comb. nov. and Cadulus scarabinorum sp. nov., followed by Fissidentalium subgiganteum; all three species are distributed in environments of 400–600 m water depth. The second most abundant Dentaliida species is Dentalium sulcosum, which is found in deeper environments (> 600 m). There are also species distributed in shallower environments (200–400 m), such as Fissidentalium matanzasense. Finally, there is no significant latitudinal species turnover, so the existence of only one paleobiogeographic province during this time range is suggested by the scaphopod fauna.

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DOI: 10.3897/sjp.145.183721

Authors: Matthew Edward Scarborough, Heinz Furrer, Torsten M. Scheyer, Marcelo R. Sánchez-Villagra, Jorge Domingo Carrillo-Briceño

Abstract: Here we report on the anatomical re-investigation of a Late Pleistocene (Middle Würmian Interstadial, MIS 3, ca. 40–50 ka BP) perinatal woolly mammoth excavated in 1890-91 from Niederweningen, Switzerland, the first perinatal mammoth ever scientifically studied. In order to narrow down its age at death we compare perinatal woolly mammoths and African elephants in terms of their (i) ontogenetic allometry, especially in woolly mammoths from Russia, (ii) bone microstructure, (iii) tooth eruption sequences, and (iv) the timing of cranial suture closure. A distinct layer of postnatal bone deposition in the tibial midshaft and maxilla identified using micro-CT scanning, in particular, provides strong evidence of a post-natal ontogeny despite the lack of obvious wear in the dentition, suggesting an age of no more than a few months. Odontochronologically, the individual probably belongs to Jachmann’s (1988) Dental Stage 1 (3 months - 2 years), and tiny pits in the enamel/dentin tips of lamellar edges are analogous to those seen in juvenile M. primigenius from Russia (“Lyuba”), and are variously hypothesized to be caused by initial wear, spalling, dissolution pitting, incomplete mineralization, or eruption through the gums. Additionally, we describe anisomelia of uncertain aetiology, resulting in the stunting right fore-leg, perhaps contributing to the cause of its death. Finally, we discuss the significance to ecology and extinction of an altricial life-history strategy and the relatively rapid post-natal growth evidenced in woolly mammoths, a taxon with an exceptionally long gestation period.

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DOI: 10.3897/sjp.145.187923

Authors: Zi-Xian Sui, Shuai Shao, Ya-Lei Yin

Abstract: The detailed dental anatomy of sauropod mamenchisaurids remains largely unexplored. Here, we describe a well-preserved isolated sauropod tooth from the Upper Jurassic Qigu Formation of the Turpan-Hami Basin, Xinjiang, using high-resolution micro-CT and three-dimensional reconstruction to investigate its internal anatomy. This tooth exhibits a unique combination of features of Mamenchisauridae, specifically the presence of marginal denticles restricted to the mesial margin, and a circular distolingual boss. CT scan data provide novel insights into mamenchisaurid dental anatomy and present the first three-dimensional enamel distribution in sauropod teeth. The lingual ridge forms from thickened enamel and dentine, whereas the lingual boss arises solely from dentine expansion. A labiolingual enamel thickness asymmetry appears in the apical region, convergent with certain neosauropods. The pulp cavity shows a distinct volumetric transition, expanding basally into a bulbous root canal and appearing as a labiolingually compressed lamina structure in the crown. Taxonomic comparison indicates that this tooth represents a mamenchisaurid lineage distinct from the previously only known sauropod tooth from the Qigu Formation. Our study supports a diverse sauropod assemblage in the Qigu Formation and provides new anatomical evidence for understanding sauropod dental evolution.

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DOI: 10.3897/sjp.145.181847

Authors: Sibelle Maksoud, Tamara El Hossny, Lionel Cavin, Pierre Abi Saad, Dany Azar, André Piuz, Elias Samankassou

Abstract: Cenomanian deposits are well exposed in Lebanon and consist mainly of limestones that cover about 40% of the Lebanese territory. The sedimentary series is rich in fish fossils known from a distinct level in three outcrops dating from the Cenomanian: Haqel, Hjoula and Nammoura. These sites are known for the exceptional preservation of their fossil content. However, the stratigraphic assignment of the fossil-bearing level is controversial. We aim to address this controversy by measuring micropalaeontological samples we collected across facies outcropping at each of the three Konservat-Lagerstätten. The micropalaeontological inventory focusing on benthic and planktonic foraminifera identified at a family and a generic level and, where possible, at a specific level, is provided. Benthic foraminifers identified include Biokovinidae, Charentiidae, Cuneolinidae, Dicyclinidae, Mayncinidae, Nezzazatidae, Orbitolinidae, Spiroplectamminidae, Gavelinellidae, Alveolinoidea, Hauerinidae, Spiroloculinidae and other Miliolidae. Amongst the planktonic foraminifers, Hedbergellidae were identified (Globigerinelloididae, Heterohelicidae and Rotaliporidae). Additionally, several calcispheres were identified. Other biogenic components were identified, including rare dasycladalean algae, bryozoans, ostracods, echinoderms and bone debris. Overall, the microfossils indicate a middle Cenomanian age, based on the presence of Conicorbitolina conica and Favusella washitensis present within the Haqel and Hjoula Lagerstätten. The macrofossil assemblages consisting of echinoids and ammonites occurring above and/or below the Lagerstätten are surprisingly not in accordance with dating obtained by microfossils and give a late Cenomanian age for Haqel and Hjoula outcrops. In addition to the palaeontological studies, we conducted geochemical analyses to detect potential palaeoenvironmental signals. However, analysis of oxygen and carbon isotopes from the three outcrops did not recover any significant shifts across facies. Finally, an ichthyofauna inventory is compiled, based on data gathered from fieldwork and literature. The fish assemblage is unique, being the most speciose ever reported from the Mesozoic. The Haqel and Hjoula sites have approximately half of their species in common, while the Nammoura site has approximately 20% of its species in common with the other two localities. The comparison of the Lebanese fish faunas is discussed, as well as the origin of the Haqel and Hjoula assemblages. The geographically restricted sites of Haqel and Hjoula are tentatively interpreted as submerged sinkholes with favourable living conditions in the water column and with low-oxygen levels at the bottom that favoured the exceptional preservation of carcasses. The overlap of fish species across different beds representing distinct environments raises important palaeobiological and palaeoecological questions surrounding the Lebanese Lagerstätten.

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DOI: 10.3897/sjp.145.188799

Authors: Wahiba Bel Haouz, Abdelouahed Lagnaoui, Christian Klug, Lahssen Baidder, Mehdi Maanan

Abstract: This article provides a description of the invertebrate trace fossils from the Hamar Laghdad region of Tafilalt in Morocco. These ichnoassemblages occur in Middle Devonian marly limestone layers, which are characterised by varying clastic content and different degrees of dolomitisation. These Eifelian and Givetian ichnoassemblages comprise: (i) Eifilian ichnoassemblages consisting of Arenicolites isp., Crescentichnus antarcticus, Selenichnites hundalensis and Osculichnus cf. labialis; (ii) a Givetian ichnoassemblage containing Arenicolites isp., Diplocraterion isp., Sinusichnus sinuosus, and Thalassinoides paradoxicus. The Eifelian strata were deposited in a moderately shallow inner shelf environment, which have been changed to a deeper inner shelf setting during the Givetian. This environment was characterised by high energy levels and a high concentration of organic matter. Some of these ichnotaxa are commonly referred to feeding of xiphosurans or trilobites, traces of suspension feeding and dwellings of polychaete worms and crustaceans, deposit-feeding non-decapod crustaceans, as well as deposit-feeding and dwelling of crustaceans. The present comprehensive ichnological analysis is important in at least three aspects: (1) it reports the oldest occurrences of Selenichnites and Sinusichnus in Africa and one of the oldest in the world; (2) It suggests a more ancient root for the represented complex behaviour of modern arthropods than previously thought; (3) It contributes to the understanding of the environmental deposit settings. The great palaeobiodiversity of Hamar Laghdad includes not only the skeletal record, but also ichnofossils. Both records indicate regional favourable environmental settings, characterised by local topography that varied over time and space, formed by several cold and hydrothermal seeps combined with sea-level fluctuations and currents.

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DOI: 10.3897/sjp.145.178570

Authors: Andrej Čerňanský, Georgios L. Georgalis, Maeva J. Orliac, Jeremy E. Martin

Abstract: Reptile faunas from the late middle Eocene of Europe are rare. Here, we report on lizards, snakes, turtles and crocodiles from the Lavergne locality in the Quercy Region (France). Reptiles here are diverse, represented by (at least) 16 taxa. Lizard assemblage consists of Gekkota, Pleurodonta, Scincidae, Lacertidae, Glyptosauridae, Anguidae and Palaeovaranidae. Snakes are represented by the enigmatic alethinophidian Platyspondylia sudrei, the ?tropidophiid Cadurceryx filholi, the pythonoid Palaeopython cadurcensis, the booids ?Eoconstrictor sp. and Dunnophis cadurcensis, an indeterminate potential russellophiid, whereas several remains are only identified as indeterminate alethinophidians. Besides squamates, Testudinoidea and Crocodylia are also present; because of the extreme rareness of the latter group in the Quercy area, we also describe here some additional crocodylian specimens from the “old collections” of Quercy. Scincids are firstly reported from Lavergne, including a new taxon, Lavergnesaurus lamarcki gen. et sp. nov. The fauna indicates a relatively warm temperature as demonstrated by thermophilic taxa. Lavergne yields a relatively similar (not identical) herpetofauna as Le Bretou (France) and Mazaterón (Spain). However, Lavergne and Le Bretou appear to be, based on current knowledge, more similar to each other when lizards and snakes are considered. Overall, the European MP 16 squamate fauna does not seem to be highly different from those of MP 14 or MP 17 and no faunal reorganisation or any significant extinction event can be recognised at the middle – late Eocene boundary in Europe. In fact, larger faunal changes are recognisable when early Eocene herpetofaunas are considered.

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DOI: 10.3897/sjp.145.184656

Authors: Andrea Tintori, Davide Conedera, Min Zhou, Yichen Tan, Dayong Jiang

Abstract: After more than 65 years, new well-preserved specimens of the Ladinian (Middle Triassic) Xingyi Fauna allow the redescription of the miniature peltopleuriform fish Habroichthys orientalis (Su 1959). This taxon was previously identified as Peltopleurus, but this revision highlights the diagnostic characters typical of Habroichthys. Namely, the single deep flank scale row with a final semicircular scale, the often completely fused skull roof, the thin maxilla not sutured to the stick-shaped preopercle, and the lack of teeth. For the first time in a Triassic fish, a µ-CT scan has been used to study the 3D shape of the in situ otoliths. Some peculiar features of the genus are confirmed, such as the stiff shield-like skull roof frequently found isolated and the sexually dimorphic anal hooklets likely used during mating. Juveniles and growth lines on adult scales show the presence of an ontogenetic series, with implications also for the paleoenvironmental restoration of the area. Morphological comparison revealed H. orientalis to be most similar to H. dincae from the almost coeval Pelsa/Vazzoler Lagerstätte in the Dolomites. Their presence on opposite sides of the Paleo-Tethys suggests multiple West–East population interchanges (the so-called “Triassic Silk Road”) rather than a single migration event that could previously have been hypothesized based on the Anisian appearance of the genus in Slovenia and in southern China.

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DOI: 10.3897/sjp.145.185785

Authors: Siyan Zhao, Jiachun Li, Gilles Cuny, Zuoyu Sun

Abstract: A taxonomic study of four tooth genera of euselachian sharks from the Ladinian–Carnian interval of the Guizhou and Yunnan Provinces, South China is presented. They include one euselachian shark of uncertain affinity, two indeterminate neoselachian sharks and one potential hexanchid shark. These four taxa display non-durophagous feeding behaviour, including grasping-swallowing, grasping, tearing and cutting strategies. High-resolution micro-CT scans and 3D reconstructions reveal that Euselachii gen. et sp. indet. and Neoselachii gen. et sp. indet. 1 possess orthodont teeth. Euselachii gen. et sp. indet. exhibits a prominent longitudinal vascular canal, but lacks an ascending pulp cavity, while Neoselachii gen. et sp. indet. 1 features two longitudinal vascular canals and a vascular cavity that ascends into the main cusp. To our knowledge, this study provides the first three-dimensional documentation of dental vascularisation in Triassic chondrichthyans.

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DOI: 10.3897/sjp.145.187852

Authors: Arnaud Begat, Eduardo Villalobos-Segura, Manuel Amadori, Stefanie Klug, Jürgen Kriwet

Abstract: The majority of the fossil records of elasmobranch fishes (sharks, rays, skates) consists of isolated teeth and dermal denticles. Over their long and complex evolutionary history, dental remains are particularly indicative of the group’s plasticity and adaptability, which has hampered the classification of fossil species with highly specialised dental morphologies that deviate from those of extant species. One of such cases is †Synechodus prorogatus recovered from Middle and Late Jurassic deposits in Poland and Germany. Its original description and diagnosis were based on a single complete and two very incomplete teeth, which showed a very peculiar morphology with some features resembling several groups. These similarities resulted in its placement within synechodontiforms. However, subsequent findings showing numerous differences with the type species of the genus, †Synechodus dubrisiensis, cast doubt on its assignment within this group and this genus. Here, we describe new material from Upper Jurassic offshore deposits in SW Germany, which provides additional information about this species. We conducted a comprehensive morphological comparison between †S. prorogatus, various Jurassic selachian taxa and the type species of †Synechodus, †S. dubrisiensis (Late Cretaceous, England), confirming the taxonomic distinctiveness of this Jurassic species, which requires the establishment of a new genus, †Curvorudentis, with †C. prorogatus gen. et comb. nov. being type species. The discovery of this taxon in Late Jurassic deposits of Germany represents its stratigraphically youngest occurrence, extending its chronostratigraphic range and geographical distribution. †Curvorudentis prorogatus is considered here a galeomorph shark, rather than being a member of the stem clade †Synechodontiformes, although its precise systematic position within this group remains ambiguous.

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DOI: 10.3897/sjp.145.175168

Authors: Kazım Halaçlar, Chien-Hsiang Lin

Abstract: Fossil records of porcupines (Hystrix) from island environments in East Asia have never been reported, leaving their Pleistocene dispersal and biogeographic history poorly understood. This study describes fossil remains of Hystrix subcristata from the Chochen–Tsailiao locality, south-western Taiwan. The locality, part of the Chiting Formation in Tainan, is dated to the Middle Pleistocene. The collection includes a well-preserved upper molar (M1/2), a lower last premolar (p4), a fragmentary lower molar (m1/2) and three fragmentary incisors. Biometric analysis indicates that the Chochen–Tsailiao specimens are smaller than H. refossa, but larger than H. lagrelii and H. vinogradovi and closely comparable in size to H. subcristata. Morphological features further corroborate this identification. This discovery is the first record of H. subcristata from Taiwan, representing both its easternmost known occurrence and the first island evidence for the genus, contrasting with all prior records which consisted only of mainland forms.

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DOI: 10.3897/sjp.145.182813

Authors: Sergio M. Nebreda, Luis M. Chiappe, Guillermo Navalón, Javier C. Terol, Francisco J. Serrano, Ángela D. Buscalioni, Jesús Marugán-Lobón

Abstract: The fossil record of Early Cretaceous enantiornithine birds from the Iberian Peninsula is the most significant in the world outside of China. Despite its historical relevance, taxonomic diversity, and relative abundance, adult cranial remains had not been reported before. In this study, we describe a new enantiornithine species, Gorgonavis alcyone gen. et sp. nov. based on a disarticulated skull from the Early Cretaceous locality of Las Hoyas (129–126 Myr; Cuenca, Spain), the first adult cranial remains of a bird from this fossil site. Digital imaging of the µCT-scanned fossil remains shows that Gorgonavis is characterized by a slender and elongated rostrum in which teeth are restricted to the premaxillary corpus, a thin, edentulous maxilla, and a jugal bone with an elongated and strongly angled postorbital process. Despite the fragmentary nature of the holotype, comparative anatomy and phylogenetic analyses suggest the identification of the new species as a longipterygid, a distinct clade of Enantiornithes characterised by an elongated rostrum, a cranial configuration consistent with the new fossil. Gorgonavis represents the oldest occurrence of an enantiornithine with relative rostral elongation outside of the Jehol Biota. The new discovery suggests that some specialised early enantiornithine lineages had a broader geographical, and more ecologically diverse distribution than previously thought.

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DOI: 10.3897/sjp.145.180388

Authors: Saverio Bartolini-Lucenti, Marie Meyer, Samuele Frosali, Joan Madurell-Malapeira, Wenhui Liu, Loïc Costeur, Damien Becker, Davit Vasilyan

Abstract: We describe a new fossil raccoon dog from the Late Pliocene site of Jradzor, Armenia, a key site to understand biogeographic connections and dispersal between Asia, Europe, and Africa. The specimens analysed here for the first time exhibit a mosaic of primitive and derived cranial and dental traits, distinguishing them from known taxa such as Nyctereutes tingi (e.g. elongated cranium, reduced subangular lobe), N. sinensis (e.g. molar proportions, sulcal pattern), and N. megamastoides (e.g. absence of squared M1 morphology). Virtual reconstruction of the endocranium reveals a unique sulcal and gyral pattern, including a parenthesis-shaped gyrus sigmoideus and a deeply developed sulcus pseudosylvius, placing it morphologically closer to Canini than extant Vulpini. Considering these features, we propose to ascribe it to a new Nyctereutes species. Morphometric and geometric morphometric analyses support its taxonomic distinctiveness and suggest ecological and behavioural affinities with jackal-like canids. Notably, the relative development of the rostral portion of the cerebrum implies a social structure more complex than that of extant Nyctereutes, suggesting the possibility of seasonal pack formation. Additionally, we reassess several neuroanatomical traits previously considered diagnostic, such as the cerebellar vermis and sulcus endomarginalis, revealing greater variability within Nyctereutes and challenging previous phylogenetic assumptions. These findings underscore the Pliocene diversification of the genus and highlight the Caucasus as a pivotal region in canid evolution. The erection of a new Nyctereutes species enriches our understanding of canid paleobiology and provides new perspectives on the evolutionary trajectories of hypocarnivorous canids.

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DOI: 10.3897/sjp.145.177453

Authors: Maia Bukhsianidze

Abstract: Seven ruminant taxa have been identified at the Pliocene Jradzor site in Armenia: Bovini indet., Gazellospira sp., Antilopini indet., Caprinae indet. 1 (cf. Eosyncerus), Caprinae ndet. 2, Caprini indet., and Cervinae indet. Jradzor is an exceptionally well-dated site. The ruminant remains derive from two layers dated to the end of the Early Pliocene (ca. 4 Ma) and the late Pliocene (ca. 3.3 Ma). These horizons correspond to a poorly known interval in Southwest Asia – the Late Ruscinian, MN15 and early Villafranchian, MN16a – and provide insights into the faunal composition of the South Caucasus.

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DOI: 10.3897/sjp.145.181371

Authors: Damien Becker, Rémi Lefebvre, Robin Saulnier Masson, Davit Vasilyan

Abstract: Hyracoidea is a group of afrotheres that is today represented by three extant genera, but its fossil diversity is much greater. While most recent palaeontological studies have focused on documenting the earliest radiation of the group (Eocene–Oligocene), fewer works have attempted to highlight the later diversification (Miocene–Pleistocene) of large hypsodont forms that dispersed across the Eurasian continent. Herein we describe a newly discovered, well-preserved skull from the late Pliocene (3.3 ± 0.03 Ma) locality of Jradzor (Armenia), attributed to a new representative of late-diverging Eurasian Pliohyracidae, assigned to a new genus and species, which is notably characterised by a dental formula lacking an upper canine. The range of the new form is so far restricted to the latest Pliocene (early MN16) in Armenia. Comparison with previously described pliohyracids and a phylogenetic analysis including, for the first time, a substantial sample of Eurasian Neogene Pliohyracidae support the monophyly of this family under its least inclusive definition. The analyses support Titanohyracidae as the sister group of pliohyracids. We therefore tentatively provide the first phylogenetic definition of the family Pliohyracidae. Except for the unstable position of the incomplete and enigmatic Hengduanshanhyrax, relationships within the family are consistent with a biogeographical history involving dispersal of pliohyracids in Eurasia from Africa. Higher-level relationships, notably with Procaviidae and Palaeogene genera, remain to be clarified in future studies aimed at accurately delineating the diversity of both modern and fossil hyracoids.

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DOI: 10.3897/sjp.145.183361

Authors: Sara G. Arranz, Souzanna Siarabi, Sharrah McKenzie, Isaac Casanovas-Vilar, David M. Alba

Abstract: The suid assemblages from Europe experienced considerable turnover during the Vallesian (MN9-MN10, early Late Miocene), ultimately leading to a marked decline in diversity during the Turolian. To provide further insight into the timing and paleoecological context of this Vallesian turnover in the suid assemblages, here we revisit the taxonomic composition of the suids from the Late Miocene (9.8 Ma) fossil locality of Can Llobateres 1 (CLL1; Vallès-Penedès Basin, NE Iberian Peninsula), with emphasis on species other than the small tetraconodontine Parachleuastochoerus crusafonti (for which CLL1 is the type locality). Although CLL1 is one of the most thoroughly sampled Vallesian sites from Europe, a recent revision of the faunal list evinced that the occurrence of multiple large mammals is based on fossil remains that were described many decades ago or that have never been published, leading to potentially misleading or, at least, insufficiently substantiated attributions. According to published accounts, three additional suid species are recorded at CLL1, being much scarcer than Pa. crusafonti: the listriodontine Listriodon splendens, the suine Propotamochoerus palaeochoerus, and a large tetraconodontine variously assigned to Versoporcus steinheimensis or ‘Parachleuastochoerus’ valentini. Our revision of the available remains, including unpublished material recovered from the 1980s onward, confirms the presence of the two former species and the assignment of the large tetraconodontine to ‘Pa.’ valentini. On biochronological grounds, the association of these taxa is characteristic of the early Vallesian, with the record of L. splendens representing the last well-dated occurrence of this species. From a paleoenvironmental viewpoint, the suid assemblage from CLL1 is consistent with previous inferences indicating the presence of a densely forested and humid environment with more open habitats nearby.

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DOI: 10.3897/sjp.145.180374

Authors: Anaïs Travers, Marine Fau, Michel Roux, Pauline Coster, Bertrand Lefebvre

Abstract: A new starfish fauna from the Late Burdigalian (Early Miocene) of the Apt basin (Rhodano-Provençal gulf, southeastern France) is described here. This new starfish fauna comes from accumulation levels of marine invertebrates, including exceptionally well-preserved pectinid bivalves and echinoderms. Among the echinoderms, the sea urchins are the most abundant, closely followed by the starfish. This is the first time the starfish fauna is being studied in detail. Here are described twelve additional specimens of Lacosteaster lauerorum Gale & Ward, 2024 (Solasteridae, Valvatida) with the first description of the abactinal face of the species, an undetermined species of Astropecten (Astropectinidae, Paxillosida), and two new genera and species: Cruciformaster pedicellarius gen. nov. et sp. nov. (Oreasteridae, Valvatida) and Menerbesaster bongrainae gen. nov. et sp. nov. (Echinasteridae, Spinulosida).

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DOI: 10.3897/sjp.145.179154

Authors: Lorenzo Lustri, Lukáš Laibl, Luis Collantes, Jana Bruthansová, Martina Nohejlová, Yu Liu, Stephen Pates

Abstract: Zonozoe drabowiensis Barrande, 1872 and Zonoscutum solum Chlupáč, 1999 are rare and incompletely preserved arthropods from the Upper Ordovician of the Czech Republic. Their classification has been a subject of debate for over a century due to the limited number of specimens, lack of knowledge related to post-cephalic morphology and the absence of clear diagnostic features. They were previously considered as members of Aglaspidida, an extinct group of arthropods from the Cambrian and Ordovician, within Vicissicaudata, a branch of the larger arthropod clade Artiopoda. Herein, we analysed the cephalic outlines of Zonozoe and Zonoscutum to determine whether their shapes align more closely with vissicaudatans than with other early Palaeozoic arthropods, offering a new morphological perspective on their systematics. We assembled a data set of cephalic outlines each representing one of thirty-three early Palaeozoic species, including Zonozoe, Zonoscutum, nine euchelicerates, six aglaspidids, three cheloniellids, and a selection of other artiopodans. We quantified their shape using elliptical Fourier analysis. Principal component analysis (PCA) and linear discriminant analysis (LDA) place Zonozoe within the vicissicaudatan morphospace, and Zonoscutum in their proximity, clearly distinguishing them from euchelicerates. These data add support to the most conservative classification of Zonozoe and Zonoscutum within Artiopoda, while strengthening the case for a more specific affinity with Vicissicaudata, helping to resolve a 150-year-old taxonomic uncertainty. More broadly, this study demonstrates the value of outline-based morphometrics in aiding systematic hypotheses when discrete characters are unavailable or scarce, offering a reproducible tool for re-evaluating other problematic fossils.

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DOI: 10.3897/sjp.145.179108

Authors: Mariano Jesús Tapia, Jose Ignacio Cuitiño, Eduardo Guillermo Ottone, María Verónica Guler, Viviana Dora Barreda, Luis Palazzesi

Abstract: During the Early Miocene (ca. 23–16 Ma), Patagonia underwent pronounced climatic reorganisations that influenced distribution patterns and biodiversity across terrestrial and marine ecosystems. Here, we explore the response of the floras from south-western Patagonia to the climatic shifts that occurred during the early Burdigalian (ca. 20 Ma–18 Ma), just before the onset of the Miocene Climatic Optimum (MCO), which took place between 17 Ma and 15 Ma. Using fossil spores and pollen grains recovered from the El Chacay Formation (south-western Patagonia), we found a ~ 50% increase in diversity from ~ 20 Ma to ~ 18 Ma. The major difference between the two ages lies in the number of rare species (singletons and doubletons) according to our non-asymptotic standardisation analysis. The increasing trend in richness mirrors the re-appearance of many plant species with predominantly tropical and subtropical current distributions (e.g. Cupania, Ilex, Arecaceae) that had severely declined from the high latitudes during the cooling trend of the Oligocene-Miocene Transition (~ 23 Ma). Overall, the recovered assemblages point to the dominance of closed-canopy forests although the record of open vegetation elements — that would later expand — became evident. Our finding reveals that plant richness increased prior to the onset of the MCO, though not reaching the peak levels observed during this climatic optimum.

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DOI: 10.3897/sjp.145.177263

Authors: Martin Ebert

Abstract: The pycnodontiform genera Macromesodon and Apomesodon from the Upper Jurassic and lowermost Cretaceous of Central and Western Europe are described in detail and their union into one genus is rejected. Nomenclature problems are explained and the differences between these two genera are described, supplemented by new specimens and spectacular UV photos that show new characters like sclerites and spines of the skin along with known characteristics in much better detail than what has been previously published. Apomesodon differs from Macromesodon mainly in the dentition, the more prominent dorsal apex, the scale pattern, the shape and ornamentation of the body scales and the articulation of neural arches and spines. Further taxa are assigned to these two genera for the first time, and a comparison of these genera with closely related taxa is made. Additionally, a new phylogeny of the Pycnodontomorpha is presented, in which the families of the basal Pycnodontiformes, Macromesodontidae and Brembodontidae, are redefined.

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DOI: 10.3897/sjp.145.181868

Authors: Qi Li, Alexander Bi, Qian Li

Abstract: Asian ctenodactyloids were highly diverse in the Paleogene. As early rodents, they provide important insights into the earliest evolution of the rodent brain. Here, we describe the first virtual endocasts of the early Eocene Exmus mini and the Oligocene Bounomys ulantatalensis and compare them with extant taxa (Ctenodactylus sp. and Pectinator spekei). From the Eocene to the present, the endocasts of ctenodactyloids reveal a reduction in olfactory bulb size, increased neocorticalization, expansion of the temporal lobes, a decrease in petrosal lobule size, and an overall increase in encephalization. Specifically, the cerebrum changes from an ovoid to a teardrop shape due to lateral expansion of the temporal lobes, and the petrosal lobule becomes much smaller in extant taxa. A reduction in the olfactory bulbs and petrosal lobules, and an increase in body mass not proportional to brain size, were observed from the early Eocene E. mini to the early Oligocene B. ulantatalensis, a change that may reflect ecological shifts during the Eocene–Oligocene transition.

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DOI: 10.3897/sjp.145.175636

Authors: Antoine Pictet, Serge Ferry, Lara Pietra

Abstract: This study presents a high-resolution biostratigraphic analysis of a nearly 30 km long platform-to-slope transect on the southern margin of the Vercors Urgonian platform, based on detailed ammonite data. The primary objective is to refine the chronostratigraphic framework of the upper Barremian Urgonian series and to reassess the timing and significance of marlstone intercalations within the carbonate succession. For this purpose, more than 100 ammonite specimens were collected along the transect at various stratigraphic levels. All standard ammonite biozones and most subzones of the upper Barremian have been confidently identified, allowing precise dating of key sedimentary and stratigraphic events. A central issue concerns the platform-to-basin correlation of Paquier’s so-called “Heteroceras marlstone”, which conflates two distinct marly intercalations of different ages under a single term. We distinguish two major marlstone complexes – (1) Ambel / Font Froide – La Béguère and (2) Pas de la Couronne / La Révolte / Lower Orbitolina Beds – that have been variously attributed to, or confused with, the Heteroceras marlstone by Paquier, his followers, and his detractors. Based on ammonite biostratigraphy, only the second complex can be confidently correlated with the Heteroceras marlstone. Together with the Upper Orbitolina Beds, these intervals are interpreted as recording three successive ingressions, the final one marking the ultimate demise of the Urgonian platform near the Barremian–Aptian boundary. This revised biostratigraphic framework clarifies long-standing stratigraphic ambiguities, strengthens regional correlations, and provides new insights into the timing and mechanisms of Lower Cretaceous carbonate platform evolution in the western Tethys.

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DOI: 10.3897/sjp.145.181236

Authors: Daniel Marty, Lionel Cavin, Allison C. Daley, Harriet B. Drage, Michael Hautmann, Walter Joyce, Christian Klug

Abstract: In 2025, with the contract with SpringerOpen running out at the end of the year, the Kommission for the SJP and the Swiss Geological Society decided to start collaborating from 2026 onwards with a publisher, where processes are more streamlined to the needs of the SJP. This will allow us to satisfy our quality standards and improve the overall quality of the journal in the future. Negotiations with Pensoft Publishers started in July 2025 and contracts were signed in September 2025. Together with the SJP, the Swiss Journal of Geosciences, also affiliated with the Swiss Geological Society, migrated from SpringerOpen to Pensoft Publishers.

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DOI: 10.1186/s13358-025-00414-0

Authors: Martin Ivanov, Václav Paclík, Àngel Luján, Madelaine Böhme

Abstract: The early Burdigalian (20.4–18.2 Ma) ophidian localities are rare in the European fossil record and with exception of Merkur-North (Ahníkov I), Czechia (early MN 3) our knowledge on the evolution of snake communities before the Early Ottnangian Cooling (EOC; 18.1–17.8 Ma) event are still strongly restricted. Here we present the unusually diversified snake community from the German Early Miocene (early Burdigalian, early MN 3) Wintershof-West locality based on the detailed comparative osteological studies with a special focus on the intracolumnar variability. The following snake taxa have been reported from Wintershof-West: Alethinophidia incertae sedis (cf. Falseryx sp.), Booidea (Bavarioboa wintershofensis sp. nov., Booidea indet.), Viperidae (Viperinae indet. – ‘Oriental vipers’, Vipera sp. [‘V. aspis’ complex]), Elapidae (‘Micrurus’ gallicus, Elapidae indet., type 1), Natricidae (Natrix cf. sansaniensis, Wintershofia robusta gen. et sp. nov., Palaeonatrix aff. lehmani, Natricidae indet., type 1, Natricidae indet.), ‘Colubridae’ (‘Coluber’ aff. caspioides, ‘Colubridae’ indet., type 1, 2, and 3, ‘Colubridae’ indet.), and Colubroidea indet.

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DOI: 10.1186/s13358-025-00420-2

Authors: Walter Joyce, Serjoscha Evers, Yann Rollot

Abstract:

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DOI: 10.1186/s13358-025-00416-y

Authors: Zuzana Strossová, Carlo Corradini, Maria Corriga

Abstract: The Želkovice locality, located in the south-western part of the Prague Synform, is well-known for its exceptionally well-preserved graptolites in black shales. Despite being studied repeatedly by several authors for over 170 years, no record of conodonts has been found until now. Both conodonts and graptolites are significant biostratigraphic groups of Paleozoic fossils. However, papers about their co-occurrence are rare. Their occurrence is tied to distinct lithofacies, which makes direct biozonal correlation difficult. Their partial overlap sheds new light on ecological niches, resilience, and the palaeoecological conditions of the environment. Determined conodonts belong to cosmopolitan taxa with a long range, inhabiting the deeper, distal parts of the shelf or continental slope. A total of 10 conodont species were identified at the same locality, spanning the entire linnaei Biozone. The occurrence of the index species Distomodus staurognathoides, whose stratigraphic range overlaps with the locally used graptolite linnaei Biozone and the internationally used guerichii Biozone, is documented. This study also documents rare specimens of pelagic fauna for the first time and discusses hypothetical parasitism and predation in conodonts and graptolites. This is the first study to describe the co-occurrence of both groups within the same lithology (black shale) and stratigraphic level, not only at the Želkovice site, but also elsewhere in the Silurian of the Prague Synform.

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DOI: 10.1186/s13358-025-00418-w

Authors: Joaquin Bogado, André Pinheiro, Pedro Romano

Abstract: The Bauru Group of the Paraná Basin (Upper Cretaceous) has yielded a rich assemblage of fossil turtles, with nine formally named species. However, many of the taxa described for this unit are poorly known, being considered nomina dubia by most authors. One such taxon is “Podocnemis” brasiliensis, described in the 1930’s and known only from its lectotype, a fragmentary plastron. In this paper we present new turtle remains that are attributable to “P.” brasiliensis, preserving parts of the plastron that were lacking in the lectotype. This novel anatomical information has permitted us to emend the diagnosis of “P.” brasiliensis and recognize it as a valid species of Pan-Podocnemididae, although its phylogenetic position within that clade is still unsettled. Fragmentary specimens that had been attributed to “P.” brasiliensis in the past were revised, and we concluded they cannot be confidently assigned to this taxon. We also analyzed variation in average shell thickness among podocnemidoids, to evaluate whether this variation was correlated with taxonomic distinctions. Though we could not estimate the average shell thickness for “P.” brasiliensis, our results demonstrate that the species Bauruemys elegans has a relatively thinner shell in comparison to other South American podocnemidoids.

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DOI: 10.1186/s13358-025-00413-1

Authors: Felix Snoodijk, Teresa Calderón, George Lyras, Alexandra Van Der Geer

Abstract: Insular conditions, such as reduced levels of resources, predation and competition, may affect life history traits of island mammal species, promoting a shift towards a slow life history. This pattern has been found in several species of insular dwarf deer but has not been tested for island deer that were subject to gigantism, which may evolve opposite life history shifts. The Pleistocene deer genus of Crete (Greece), Candiacervus, provides an ideal case to test this potential difference, because this endemic genus comprised dwarf as well as giant forms in an otherwise depauperate mammalian fauna. Here, we tested maturation patterns in this genus using a palaeohistological approach. We found that small, medium and larger forms of Candiacervus all demonstrated delayed skeletal maturity compared to their putative ancestor fallow deer (Dama dama) as well as similar-sized mainland deer. This is the first report showing that insular deer that are either subject to gigantism or retained ancestral size, also displayed adaptations to a slow life history similar to insular deer that underwent dwarfism. This research contributes to our understanding of how insular conditions may influence life history patterns in a species radiation of deer.

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DOI: 10.1186/s13358-025-00407-z

Authors: Vittorio Pieroni

Abstract: A Middle Triassic gastropod fauna from the San Salvatore Dolomite (Anisian/Ladinian boundary, Southern Alps) is here described in detail for the first time. The material was collected from the type locality Monte San Salvatore (Southern Switzerland, Canton Ticino) and from the Rasa Valley (Varese, Lombardy, Northern Italy); the latter was particularly rich in gastropods. The San Salvatore Dolomite represents a Middle Triassic carbonate platform, close to the time equivalent, usually anoxic basin of the well known Besano Formation (Monte San Giorgio), where gastropods are extremely rare. The taxonomic diversity of the San Salvatore Dolomite is here represented by 39 species, among them caenogastropods are dominant. Patellogastropods are rare and contain endemic species. Vetigastropods and basal taxa are highly diversified but often represented by one specimen per species only. Neritimorphs, despite the abundant specimens at hand, show a lower species richness. Heterobranchs are absent. The Paleozoic genera Planotectus and Knightinella are documented for the first time in the Middle Triassic with two new species: Planotectus chiusarellae sp. nov. and Knightinella? olonae sp. nov. Open nomenclature was used for some species, among them some can be new. Some shells show also traces of the original pigmentation.

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DOI: 10.1186/s13358-025-00415-z

Authors: Minguk Kim, JONGYUN JUNG, Walter Joyce, Jae-Il Park, Hye-Yeon Jung, Hyemin Jo, Min Huh

Abstract: Here, we present a new Cretaceous carettochelyid turtle, Byeoljubuchelys yeosuensis gen. et sp. nov., from the Lower Cretaceous Hasandong Formation of Yeosu, Korea. A nearly complete shell and select elements of the girdles and limbs provide crucial insight into the evolution and aquatic adaptation of this family. Phylogenetic analyses place Byeoljubuchelys yeosuensis at the most basal position within Carettochelyidae. The mid-sized plastron of Byeoljubuchelys yeosuensis appears to be plesiomorphic for the group. The expansion of the plastron during carettochelyid evolution, especially during the Paleogene, may be an evolutionary response to increasing body size or the threat of mammalian predators. Although the shell of Byeoljubuchelys yeosuensis lacks distinct scute sulci, traces are apparent that are reminiscent of juvenile scutes in the extant Carettochelys insculpta, suggesting that scute loss was facilitated in trionychian evolution through the thickening of the epidermis. Byeoljubuchelys yeosuensis possesses a plesiomorphic humerus with a proximally located lateral process and a sigmoidal shaft lacking torsion, implying rowing locomotion rather than the underwater flapping seen in more recent carettochelyids. The repeated acquisition of a softshell in two clades of trionychians during the mid-Cretaceous may be related to an environmental shift towards humid climates at that time, perhaps reflecting a remarkable adaptation to freshwater ecosystems.

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DOI: 10.1186/s13358-025-00412-2

Authors: Ailin Wang, Zhijie Zhang, Haoyu Liu, Yuxia Yang

Abstract: The Cretaceous Period represents a critical juncture in the evolution of insects, however, taphonomic biases associated with amber preservation obscure essential morphological evidence necessary for deciphering macroevolutionary dynamics. Although microcomputed tomography (micro-CT) provides high-resolution imaging, its limitations in reconstructing fragmented amber fossils necessitate innovative solutions. This study introduces an open-source multimodal framework that integrates Blender 4.2 with micro-CT volumetric data and 2D optical imaging to restore the morphological characteristics of compromised specimens. Using a mid-Cretaceous soldier beetle (Sanaugulus sp.) from Burmese amber as a case study, we successfully achieved digital reconstruction of the elytra, antennae, pronotum, and legs through skeletal rigging techniques and HDR (High-Dynamic Range)-optimized visualization methods. By addressing taphonomic constraints and facilitating exploration within evolutionary morphospace, this framework tackles critical challenges in paleontological imaging while improving methodological accessibility through open source tools. It effectively bridges interpretative gaps present in compromised fossil specimens, thereby advancing future research endeavors in paleoecology, phylogenetic analysis, and biomechanical modeling. The capacity to generate museum-ready 3D models with interactive articulation ranges positions this framework as a transformative tool for both macroevolutionary research and public engagement in studies concerning deep-time biodiversity.

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DOI: 10.1186/s13358-025-00417-x

Authors: Dingge Guo, Joan Madurell‑Malapeira, Kun Xie, Zhaoyu Li, Chao Qin, Lu Li, Qigao Jiangzuo, Shiqi Wang

Abstract: Megantereon is an iconic sabertoothed cat known from the Quaternary deposits of the Old World, being its evolutionary scenario and phylogenetic relationships hotly debated the last decades. Several authors proposed that there is only one species, i.e. M. cultridens, or two species, plus M. whitei in Eurasia and Africa of Pleistocene, while some authors proposed multiple species present. Here we describe a mostly complete cranium and several fragmented mandibular fragments of a very large and robust form of Megantereon from Bajiazui, Qingyang, northwestern China, assigned to M. inexpectatus. Several new skulls/crania of M. nihowanensis from Longdan (Gansu, China) were analysed and they further provide a better basis for evaluating the intraspecific variability of this lineage. The analyses here reported, support the recognition of two species from a single lineage of Megantereon in northern China since the earliest Pleistocene to the middle Pleistocene, with smaller M. nihowanensis in the Gelasian, and slightly larger and more robust M. inexpectatus with more derived dentition during the Calabrian to the early Middle Pleistocene. This scenario is different from what is seen in Europe, where the primitive M. cultridens evolved to smaller and dentally specialized M. adroveri.

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DOI: 10.1186/s13358-025-00419-9

Authors: Marko Yurac, Matteo Belvedere, Christian Salazar, Javiera Méndez, Christian Meyer

Abstract: The bone record of non-avian dinosaurs from Chile consists of sauropods, theropods, ornithopods, and rare thyreophorans. However, the ichnological record is potentially even more abundant and plays a significant role in supplementing and enlarging the Chilean dinosaur record. Rich track-bearing levels, dated from the Upper Jurassic to the Lower Cretaceous, are known mainly from northern Chile. This study describes for the first time a stratigraphic section of the Majala Formation (late Oxfordian) in the Quebrada Huatacondo. In this section, five track-bearing levels were recorded confirming the presence of ichnites of giant (lengths between 51 and 52.8 cm), large (lengths between 43.5 and 46.5 cm) and medium (lengths between 25 and 27 cm) theropods. One surface (Maj5) has more than 25 footprints of minute to small theropods (footprints lengths ranging from 8 to 13 cm). Morphological parameters from the small footprints are similar to Carmelopodus, Grallator, and Therangospodus. Meanwhile, some similarities were observed with Kayentapus and Megalosauripus for the range of medium to giant footprints. When comparing track sizes from Quebrada Huatacondo with other theropod tracks from the Tarapacá Basin (Quebrada Chacarilla and Río San Salvador localities), their dimensions and morphology are similar, but the small tracks are substantially smaller than those from the other localities and constitute to the smallest footprints found on the western margin of Gondwana for this time. These tracks and trackways represent the oldest dinosaur footprints reported for Chile and the western margin of Gondwana.

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DOI: 10.1186/s13358-025-00410-4

Authors: Gabriel S. Ferreira, Serjoscha Evers

Abstract: Even though many early stem turtles are known from relatively well-preserved skulls, their neuroanatomy remains poorly understood, limiting insights into key cranial and ecological transitions. Here we reconstruct the brain, nerves, inner ears, olfactory endocasts and arteries of two early stem turtles—the Early Jurassic Kayentachelys aprix and the Middle Jurassic Eileanchelys waldmani—based on high-resolution imaging. These species document key phases of turtle cranial evolution. Our analysis documents intermediate conditions of Jurassic mesochelydians between earlier Triassic stem turtles such as Proganochelys quenstedtii and crown Testudines. We show that changes in the canalis cavernosus, geniculate ganglion positioning, and braincase architecture are related to cranial stiffening in turtles. Whereas Kayentachelys aprix retains plesiomorphic features of Triassic testudinatans (e.g., separation of recessus scalae tympani and cavum acustico-jugulare; flat processus interfenestralis morphology) or intermediate features (e.g., cranio-quadrate space modified to short canalis cavernosus; clearly tympanic stapes but with robust morphology; reduced prootic foramen but absence of secondary braincase wall of parietal-pterygoid contact), Eileanchelys waldmani shows essentially ‘modern’ braincase architecture, including a ventrally inclined processus interfenestralis and a fully developed cavum tympani. Additionally, anatomical traits associated with olfaction and hearing provide insights into the paleoecology of these taxa, supporting a terrestrial lifestyle for Kayentachelys aprix and aquatic adaptations in Eileanchelys waldmani. Our study highlights the utility of neuroanatomical data in refining hypotheses of turtle cranial evolution and ecology, and underscores the importance of Jurassic stem turtles for understanding the origins of crown-group traits.

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DOI: 10.1186/s13358-025-00411-3

Authors: Andrea Villa, Arnau Bolet, Jozef Klembara, Alejandro Serrano-Martínez, Àngel Luján, Josep Fortuny, Massimo Delfino, Burkhard Schillinger, David Alba

Abstract: Post-Palaeogene anguids from Europe have been referred to three extant genera: Anguis, Ophisaurus s.l. (including Dopasia and Hyalosaurus), and Pseudopus. In recent years, a higher generic diversity has started to be recognised, with extinct genera described from both Neogene and Quaternary localities. We here describe a new genus and species of anguid lizard, Fontisaurus tarumbaire gen. et sp. nov., based on a large articulated skull from the Vallesian (Late Miocene) of Sant Miquel de Toudell, in the Vallès-Penedès Basin, on which we also performed neutron CT scanning. The new lizard differs from all other anguid species from Europe, both extant and extinct, most notably in the combination of widely laterally extended anterolateral processes and medially directed anterior end of the anterolateral ventral crests in the parietal. Phylogenetic analyses using maximum parsimony and Bayesian inference support the placement of this new genus and species as a member of the Anguinae, which is currently the only anguioid clade clearly present in Europe after the Palaeogene/Neogene transition. Based on tip-dating Bayesian analyses, the divergence of this new anguid from its sister taxon within the Anguinae largely predates this transition, but uncertainties still surround its detailed phylogenetic relationships. An isolated parietal from the Middle Miocene of Griesbeckerzell 1a in Germany strongly resembles the morphology displayed by the holotype of Fontisaurus tarumbaire gen. et sp. nov. but differs from it in the sculpturing type and the development of the muscular surface. This fossil from Germany is here referred to as Fontisaurus aff. tarumbaire and implies a wider stratigraphical and geographic distribution for Fontisaurus gen. nov.

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DOI: 10.1186/s13358-025-00406-0

Authors: Jie Yang, Qing-hao Guo, Jean Vannier, Qiang Ou, Cédric Aria, Tian Lan, Xiao-yu Yang, Lin-jun Zou, Yu Wang, Chun-li Li, Xi-guang Zhang

Abstract: Modern hemichordates are remarkable by their morphological and ecological disparity, encompassing single sessile, colonial, burrowing and surface-dwelling forms, However, uncertainties remain concerning the anatomy of their early representatives and the divergence of major lineages. We describe here an exceptionally preserved and nearly complete graptolite (Hemichordata, Pterobranchia) Yunotubus gemmatus gen. et sp. nov. from the 516-million-year-old Xiaoshiba Lagerstätte, China. Its tubular construction (e.g. fusellar tissues, stolon) and colonial architecture are similar to those of extant rhabdopleurids. Our phylogenetic analysis retrieves Yunotubus as a graptolithine with high confidence, although stem nodes remain poorly resolved. Our fossils confirm that key features of the pterobranch tubular construction (e.g. clusters of tubes with oblique fusellar sutures; zooids interconnected by a stolon) have remained virtually unchanged over more than 500 million years, and that pterobranchs and enteropneusts diverged and adopted radically different ecologies very early in the evolution of hemichordates.

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DOI: 10.1186/s13358-025-00399-w

Authors: Milan Chroust, Tomasz Szczygielski

Abstract: The Turtle Evolution Database (TED) is an online database initially dedicated to fossil turtles from Czechia and Poland, featuring images and 3D models. This database aims to provide comprehensive information about fossil specimens, including their locations, ages, taxonomic identification, and related references. TED adopts the FAIR principles (Findable, Accessible, Interoperable, and Reusable) to enhance global collaboration and accessibility to lesser-known paleontological collections. TED currently includes over 250 records from 17 institutions, covering nine families of turtles and other related material. The database is freely accessible under a Creative Commons Attribution-NonCommercial 4.0 International license, promoting responsible use and broad sharing of data. Researchers worldwide are encouraged to contribute, provide feedback, and collaborate to further the understanding of turtle evolution. The database is available at https://ted.paleo.pan.pl/.

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DOI: 10.1186/s13358-025-00409-x

Authors: Adán Pérez-García, Andrea Guerrero, Santiago De Jesús, Francisco Ortega

Abstract: Several relatively complete and well-preserved shells of podocnemidid turtles from the Bartonian (late middle Eocene) fossil site of La Solana (Mazaterón locality, Soria province, central Spain), as well as other partial shell remains and isolated plates from the same locality, are analyzed here. Until now, no pleurodiran remains from La Solana or from any other outcrop in the eastern Duero Basin have been formally described. By contrast, fossils of this lineage have been recognized to be very abundant in the western region of this basin, and had been subjected to relatively numerous, detailed studies for more than five decades. Notable faunal differences were identified between the two regions of this basin, both for the turtle fauna and that of other vertebrate lineages, reptiles and mammals. The pleurodiran material identified at La Solana is attributable to Neochelys, a common and diverse genus of freshwater turtles exclusive to the Eocene of Europe. Although several species are currently recognized as valid based on the fossil record of several European countries (most of them exclusively through shell remains, with only one or a few shells being recognized for several of its representatives), the best preserved are those from the western Duero Basin. Intraspecific variability was identified for several characters in the shell of the representative of Neochelys from La Solana. The combination of characters observed in the La Solana material is not compatible with any of the species defined from the western sector of the Duero Basin. The comparative study carried out here shows that it varies systematically from other named species of Neochelys.

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DOI: 10.1186/s13358-025-00401-5

Authors: Marcos Martín-Jiménez, Javier Catalá Montolio, Adán Pérez-García

Abstract: Taphrosphyini is a diverse and geographically widely distributed lineage of bothremydid pleurodiran turtles. The first neuroanatomical reconstruction of the Paleogene genus of Taphrosphyini Taphrosphys is presented here, based on the study of a skull of the Moroccan Paleocene species Taphrosphys ippolitoi. Some osseous characters hitherto undocumented for this taxon are recognized in this specimen. Thus, among other anatomical elements, the postorbitals are documented for first time in this taxon, and the columella auris is described for the first time within Taphrosphyini. The use of the CT methodology and the three-dimensional modelling software allowed us to generate the three-dimensional virtual reconstruction of an idealized skull of Taphrosphys ippolitoi. This allows us to recognize several internal cranial structures and compare them with those of the other species of this genus. Most neuroanatomical elements of Taphrosphys ippolitoi are documented here. In addition of characters shared with all other bothremydids, others, shared exclusively with some representatives of this clade, are recognized as evidence for evaluate its lifestyle. The enlarged nasal cavity and the relatively high and wide semicircular canals of the endosseous labyrinth, confirmed here for Taphrosphyini, are convergent with those of other pleurodires identified as marine forms, including the Nigeremydini bothremydids. Thus, these and other anatomical and neuroanatomical traits observed in Taphrosphys ippolitoi are recognized as adaptative responses to marine environments.

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DOI: 10.1186/s13358-025-00408-y

Authors: Anastasiia Dubikovska, Marcin Górka, Oleksandr Kovalchuk, Małgorzata Bieńkowska-Wasiluk, Ewa Świdnicka, Zoltán Barkaszi

Abstract: Diverse assemblages of cartilaginous and actinopterygian fish fossils were recovered from Middle Miocene deposits of southern Poland (north-western part of the former Fore-Carpathian Basin). Here we describe and analyse the taxonomic composition of fish assemblages from 13 Badenian localities based on materials collected in the early 1960s. A total of 423 specimens were studied, most of which belong to ray-finned fishes and sharks. The latter is the most diverse group (13 families of 5 orders), in which sand tiger sharks (Carchariidae) and requiem sharks (Carcharhinidae) predominate. Regarding actinopterygians, 92% of the specimens belong to seabreams (Sparidae). Pristiophorus sp., Araloselachus vorax, and Raja gentili have been first recorded for the Fore-Carpathian Basin, whereas Trigonodon jugleri and Diplodus sitifensis have been first documented in the north-western part of the region. The studied fossils come from localities confined to marginal marine subtidal to shallow and deeper sublittoral zones of the basin. The majority of the revealed taxa are thermophilic and occupy pelagic, benthopelagic, and benthic habitats, although species that can also be found in deeper and cooler environments are represented in the studied sample as well. This implies a complex marine ecosystem with diverse ecological niches in the north-western part of the Fore-Carpathian Basin. Taxonomically similar fish assemblages have been reported from the Burdigalian, Langhian, and Serravallian of Europe, indicating continuity and integrity in the evolution of fish faunas in different basins of the Paratethys during the Miocene.

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DOI: 10.1186/s13358-025-00403-3

Authors: Seishiro Tada, Takanobu Tsuihiji, Donald Morgan, Lawrence Witmer, Ingmar Werneburg

Abstract: The cephalic vasculature of turtles has been explored extensively for its evolutionary history. However, the rostral portion of the cephalic vasculature has rarely been investigated compared to that of the basicranial region, despite its unique morphology among diapsids and a wide range of variation within crown turtles. Here, a broad range of diapsid taxa were examined to explore the evolution of the rostral vasculature in turtles. We show that the arrangement of the rostral vasculature specific to extant turtles, bifurcation of the maxillary artery, and the caudally shifted foramen praepalatinum transmitting the palatine artery, could at least be traced back to the mesochelydians based on osteological evidence. Although one of the oldest testudinatans Proganochelys quenstedtii had a medially shifted maxillary artery as in crown turtles, its rostral vasculature likely retained the ancestral diapsid condition, consistent with the generally plesiomorphic morphology of the cranium. The crownward evolution of the rostral vascular patterning is likely related to associated rostral morphological changes, such as the keratinous beak, nasolacrimal duct, and medial nasal gland. In addition, variations of the osteological correlates for the maxillary and palatine arteries were found in crown turtles. Trionychians have a unique large opening termed foramen intermaxillaris instead of the paired foramina praepalatina on the floor of the nasal cavity, but they were shown to be homologous based on the shared palato-nasal neurovascular pattern. Chelonioids exhibited the most deviation from the generalized turtle rostral vascular patterning. Those deviations within crown turtles are likely associated with the relevant anatomical changes of the rostrum, such as the secondary palate of cheloniids.

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DOI: 10.1186/s13358-025-00400-6

Authors: Milan Chroust, Tomasz Szczygielski, Àngel Luján

Abstract: Tortoises (Testudinidae) are a clade of turtles highly specialized to terrestrial environments, mainly living in semi-arid conditions. Herein, we present Manouria morla sp. nov., a new species of the genus Manouria, which is considered to be the most basal extant testudinid genus. The studied material comes from the Ahníkov I fossil site, formerly known as Merkur or Merkur-North, located in the Most Basin in NW Bohemia (Czechia), dated to the Early Miocene (Burdigalian, MN 3). Manouria morla sp. nov. is the oldest member of the Manouria lineage, which nowadays inhabits SE Asia only, and therefore its biogeography and plausible European origin are discussed. The specific type of multiplication of plastral scutes in the inguinal region is discussed as a new morphological character diagnostic for the genus. Based on zoological studies, specific environmental requirements of the genus Manouria allow us to use this taxon as a proxy for the paleoclimate reconstruction of the Ahníkov I fossil site which suggests a broadleaf evergreen tropical wet forest. The simplified use of fossil testudinids as a proxy for reconstructing semi-arid palaeoclimate is therefore disproven.

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DOI: 10.1186/s13358-025-00389-y

Authors: Juliette Menon, Walter Joyce

Abstract: We here provide a redescription the Late Cretaceous (Campanian–Maastrichtian) fossil marine turtle Glyptochelone suyckerbuykii to document its anatomy and intraspecific variation. This redescription highlights the complete absence of a nuchal pedestal, presence of a radiating shell surface texture pattern easily differentiated from that of coeval marine turtles, and the presence of interneural elements, a characteristic unique among Late Cretaceous turtles. A phylogenetic analysis suggests that Glyptochelone suyckerbuykii is located at the base of Dermochelyidae, a dubious result likely resulting from missing data. To allow constructing phylogenetic characters based on the presence of supernumerary neural elements, we suggest a revised classification for the midline column of the carapace of turtles based on novel homology criteria as consisting of neurals, which are outgrowths of the neural arches, as opposed to preneurals, interneurals, and postneurals, which are independent bones that form in front, within, and posterior to the neural column, respectively. We suggest use of this novel classification in future phylogenetic analysis.

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DOI: 10.1186/s13358-025-00402-4

Authors: Georgios Georgalis, Evangelos Vlachos, Francesca Camanni, Andrea Villa, Marco Pavia, Lars Van Den Hoek Ostende, Massimo Delfino

Abstract: The Late Miocene Gargano “Terre Rosse” in southern Italy has yielded a diverse vertebrate fauna that comprises an array of endemic taxa, including forms characterized by extreme sizes and unique morphologies. We here document new testudinid fossil remains from this insular assemblage. The material comprises a mandible, abundant (though mostly fragmentary) shell remains, appendicular elements, and a few vertebrae, originating from different localities within the Gargano assemblage. Based on its femur morphology, we tentatively refer the Gargano form to Solitudo, a late Neogene and Quaternary insular genus, otherwise known from a few Mediterranean islands. Unfortunately, the incomplete preservation of the trochanters hinders observation of the main diagnostic character of Solitudo, however, the similarities in the femoral head and diaphysis allow an open identification of the Gargano material as cf. Solitudo sp. Still, the Gargano tortoise offers new anatomical information on the Mediterranean insular tortoises. An interesting feature of the few preserved plastral elements is the presence of sulci as distinct raised ridges, a character that has been reported in other insular extant and extinct tortoises as well. The preserved hyoplastron has a medially straight and laterally concave humeropectoral sulcus and a wide axillary scute, pointing to some resemblance to geochelonans. Moreover, the morphology of the mandible from Gargano, which has its lingual serration reaching towards the symphyseal area, is also indicative of geochelonan affinities. If our identification is correct, the Gargano form would correspond to the earliest occurrence of Solitudo, denoting that this insular testudinid already radiated during the Late Miocene. A thorough overview of the diversity and taxonomy of insular testudinids from the Mediterranean islands is provided.

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DOI: 10.1186/s13358-025-00390-5

Authors: Marcelo de la Fuente, Ignacio Maniel, Joaquin Bogado, Pablo Ruiz, Claudia Galli

Abstract: We reassess the taxonomy of the problematic taxon “Podocnemis” argentinensis from the Maíz Gordo Formation (late Paleocene) at Quebrada Queñoal (type locality), Departamento de Humahuaca, Jujuy province, Argentina. This plastron-based species was initially named as a member of the genus Podocnemis (Podocnemididae) based on the holotype and one referred specimen. Considering the dubious generic assignment of the holotype of “Podocnemis” argentinensis, we performed a thorough revision of the morphological characters of this taxon, based on the holotype and previously undescribed specimens from the same lithostratigraphic unit in the Casa Grande-Vizcarra river area (western flank of the Mal Paso Range, Tres Cruces Sub-basin) in Jujuy province, Argentina. The new referred specimens include a collection of shells found in association with one skull from Quebrada del Agujero, as well as some shells from Quebrada del Puesto in the same region. Comparison between the extended hypodigm of “Podocnemis” argentinensis and other podocnemidids suggests the assignment of this species to a new generic entity, based on the presence of a short preorbital skull portion with steeply curved prefrontal bones, both exoccipital bones with a dorso-medial process restricting the dorsal part of the foramen magnum to a narrow cleft, lateral orbits, absence of an interorbital groove, high maxillae, a large vomer and the generalized gular, extragular and humeral scute pattern. We included this species in a phylogenetic analysis to assess its relationships with other pelomedusoid turtles. It is recovered as the sister taxon of Gestemys powelli, with which it shares the following four synapomorphies: foramen posterius canalis carotici interni outside the basisphenoid, long basioccipital, reduced nuchal embayment and dorsoventral flattening of the shell. The clade including “Podocnemis” argentinensis and Gestemys constitutes a Paleogene Argentinean lineage which is more closely related to Erymnochelyinae and Peltocephalinae than to Podocnemidinae, a position supported by a more covered adductor fossa and a large anterior opening of the cavum pterygoidei.

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DOI: 10.1186/s13358-025-00405-1

Authors: Kate Trinajstic, Zerina Johanson, Carole Burrow, Moya Smith, John Long, Alice Clement, Brian Choo, Anton Maksimenko, Vincent Dupret

Abstract: The arthrodiran placoderm Bullerichthys fascidens, from the Late Devonian Gogo Formation, Western Australia, was originally described from an incomplete headshield with only the spinal and interolateral plates known from the trunk shield. Two new specimens, both incomplete, preserve additional headshield plates enabling the reconstruction of the head. In addition, both new specimens represent different ontogenetic stages relative to the holotype, which is best illustrated in the dental plates, preserved in all three known specimens. B. fascidens presents an unusual dentition for placoderms with multiple tooth rows obliquely crossing the central region of the posterior supragnathal, one of the upper tooth plate elements. New tomographic data of the dentition support the presence of resorption in arthrodiran dentitions, associated with remodelling rather than tooth-specific loss and replacement. In the lower jaw resorbed teeth are not replaced but the biting division is modified through expansion of a new bony shearing blade presumed to have been derived from the original tooth row. Nevertheless, resorption in arthrodires such as Bullerichthys mirrors the resorption and remodelling characteristics of the osteichthyan dentition, with tooth site-specific features, differing in all respects from chondrichthyans.

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DOI: 10.1186/s13358-025-00404-2

Authors: Florian Bouchet, Clément Zanolli, Josep Fortuny, Salvador Moyà-Solà, David Alba

Abstract: Pliopithecoids are a clade of stem catarrhines represented by multiple Middle to Late Miocene genera in the Vallès-Penedès Basin (NE Iberian Peninsula). The recent description of the crouzeliid Fanchangia (Early Miocene, China) and the recognition that Pliobates (Late Miocene, Spain) is a crouzeliid enable to revisit the taxonomic affinities of some pliopithecoid remains from this basin, namely an M2 from Trinxera del Ferrocarril-Sant Quirze (SQ-TF; ~11.6–11.2 Ma), generally interpreted as a pliopithecid, and a dP4 from Can Feliu 2 (CF2; <11.2 Ma), previously considered a crouzeliid. We redescribe these remains based on both external morphology and enamel-dentine junction (EDJ), and compare them with those of other pliopithecoids. A cladistic analysis of dental features is performed using a dental matrix that includes the dP4 position, while the M2 EDJ shape is compared using landmark-based three-dimensional geometric morphometric (3DGM) analysis. Finally, body mass is estimated based on M2 size using available allometric equations. Our qualitative comparisons show that the M2 resembles in some regards the Asian anapithecines Laccopithecus and Fanchangia but is less derived than Anapithecus, while the 3DGM analysis supports its crouzeliid affinities and hints at differences from crouzeliines. In turn, the dP4 resembles that of crouzeliids, including the anapithecine Fanchangia and the crouzeliines Pliobates and Crouzelia. Given size congruence and close geographic and temporal proximity, it is likely that both specimens belong to a single, medium-sized crouzeliid species. A cladistic analysis of the two specimens simultaneously supports a sister-taxon relationship with Fanchangia within anapithecine crouzeliids. We conclude that the remains from SQ-TF and CF2 belong to the Crouzeliidae and, likely, to a medium-sized anapithecine. Given the scarcity of the material, we refrain from erecting a new species and provisionally refer to this taxon as Anapithecinae nov.—in the hope that future fieldwork will eventually recover additional, more complete material.

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DOI: 10.1186/s13358-025-00387-0

Authors: Clément Coiffard, Haytham El Atfy, Mona Darwish, Ahmed Mohamed

Abstract: The Bahariya Formation of the northern Western Desert, Egypt, is well-known for its plentiful and diverse vertebrate fossil assemblages, especially dinosaurs, and also eminent for its rich fossil macroflora. Unraveling the taxonomic and climatic inferences of this macroflora will undoubtedly provide essential insights into reconstructing this significant ecosystem and understanding plant life in the region during the early Cenomanian period. In this study, a taxonomic revision of the recovered fossil leaves, a crucial aspect of our research, enables the identification of fourteen morphotypes closely resembling those recently recovered from adjacent profiles of the Bahariya Formation. This taxonomic revision significantly contributes to our understanding of the Cenomanian floras from Egypt and their Neo-Tethys counterparts. The results from the current macrofloral record largely confirm previous data regarding the same ancient vegetation preserved in the palynological record. Moreover, sedimentological investigations, including petrography and X-ray diffraction of rock samples from the type section of the Bahariya Formation in the Gebel El Dist profile, a section closely similar to the location where the leaf fossils were recovered—play a crucial role in supporting climatic models, thereby providing reassurance and confidence in the research findings.

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DOI: 10.1186/s13358-025-00396-z

Authors: Silvio Renesto, Cinzia Ragni, Fabio Magnani

Abstract: A new virtually complete specimen of the eosauropterygian nothosauroid Lariosaurus valceresii is described. The specimen was collected in the Kalkschieferzone of the Meride Limestone (Ladinian, Middle Triassic) in the UNESCO World Heritage area of Monte San Giorgio (Switzerland/Italy). The new specimen is the first L. valceresii collected in Switzerland and the first known Lariosaurus specimen with remains of the skin. The skin is preserved as a carbon film revealing the shape of the scales. It outlines the body and limbs, showing that the hands and feet were webbed. The skin is present postaxial to both the humeral shafts and the anterior portion of the trunk suggesting the possible presence in life of large and very strong retractor muscles for the forelimbs indicative that Lariosaurus could have performed a paraxial, otariid-like, "flying-rowing" swimming for rapid acceleration.

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DOI: 10.1186/s13358-025-00398-x

Authors: Alison Rowe, Isabelle Rouget, Farid Saleh, Oulfa Belhadj, Marie Radepont, Dirk Fuchs, Pierre Saad, Denis Audo, Pierre Gueriau, Isabelle Kruta

Abstract: The Upper Cretaceous Konservat-Lagerstätten of Lebanon—the Santonian-aged Sahel Aalma (Sahel Alma), and Cenomanian-aged Hjoula (Hadjoula, Hgula) and Haqel (Hakel, Haqil)—are world-renowned for their exceptional preservation of fossil organisms. Taphonomic studies are still quite rare at these sites and have typically focused either on preservational differences between organisms or comparisons with other Konservat-Lagerstätten. Questions regarding preservational variation (whether each locality in these limestones preserves the same tissues, with the same composition, and at the same high level of occurrence, for example) have yet to be answered. Such preservation variability has implications for a variety of palaeontological analyses, including systematics, phylogenetic character coding, and palaeoecological interpretation. Here, we combine multiple imaging techniques to explore the preservation of a large sample of a single cephalopod species, Dorateuthis syriaca (n = 71). This taxon (order Octobrachia) occurs in abundance at each of the three main gladius-bearing coleoid localities and spans c.10 Ma. The observed presence or absence of tissues and organs was used to constrain the preservation potential in each of the localities, and further statistical analyses were conducted to identify if differences between localities were significant. Our results show that Haqel and Hjoula are likely to preserve more soft tissues than Sahel Aalma, mainly due to a higher occurrence of circulatory and respiratory tissues. These data highlight the need to focus on local locality conditions when studying exceptional preservation, despite the limestone composition of each of the Konservat-Lagerstätten.

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DOI: 10.1186/s13358-025-00394-1

Authors: Edwin A. Cadena, Jorge Domingo Carrillo-Briceño, Dylan Bastiaans, Tandra Fairbanks-Freund, Loïc Costeur, Torsten Scheyer

Abstract: Thalassochelydians represent one of the earliest radiations of coastal to marine-adapted turtles, spanning from the Jurassic to Cretaceous periods. This study describes Craspedochelys renzi sp. nov., a new thalassochelydian, “plesiochelyid” turtle from the Hauterivian stage of the Early Cretaceous in Colombia. It is the youngest and the only known record of “Plesiochelyidae’ outside Europe. The holotype, housed at the Naturhistorisches Museum Basel, was rediscovered after over 60 years and includes a partial shell, hindlimb bones, and caudal vertebrae. C. renzi shares key traits with “Plesiochelyidae”, including a V-shaped posterior plastral lobe lacking an anal notch; an indentation at the hypoplastra-xiphiplastra contact; an “intermediate” bone between neural 8 and suprapygal 1; a fully ossified carapace and bridge; and absence of carapacial fontanelles. Within “Plesiochelyidae”, it is assigned to Craspedochelys by its broader carapace, with an estimated length/width ratio of 4.12 for left costal 4, similar to other species in the genus; a relatively shorter plastron; and wider hyoplastra. Geological evidence links the specimen to the Moina Formation, a shallow marine deposit from the Hauterivian. This discovery expands the genus’ spatial and temporal range, underscoring its evolutionary and paleobiogeographic significance. It highlights the importance of museum collections in re-evaluating long-overlooked specimens, enriching our understanding of past biodiversity and turtle dispersal patterns.

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DOI: 10.1186/s13358-025-00393-2

Authors: Simon Linhart, Ana Zippel, Gideon Haug, Patrick Müller, Carolin Haug, Joachim Haug, Florian Braig

Abstract: Beetle larvae are common occurrences in modern terrestrial and freshwater fauna. We can assume that this was the case in the past as well, yet fossil beetle larvae are still reported relatively rarely. Here we report fossil larval specimens of the group of click beetles, Elateridae, from Kachin amber. The specific ecological role of the larvae can be gleaned from the specimens, they are predators, most likely wood-associated. The larvae seem differentiated from other common types of predatory larvae, the most common being lacewing larvae, based on a quantitative morphological comparison of head and mandible shape. We emphasise the use of fossil beetle larvae for functional ecological comparisons, even if the exact taxonomic relationships are unclear, because they can still provide important information for palaeoecological questions.

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DOI: 10.1186/s13358-025-00391-4

Authors: Orangel Aguilera, Carlos De Gracia, Félix Rodriguez, Olga De Araújo, Paulo Andreas Buckup, Philippe Bearez, Ana Linhares, Hilton Costi, Werner Schwarzhans, Loïc Costeur, Danae Thivaiou, Carla Silveira, Ricardo Lopes

Abstract: Although lutjanid snappers are widely distributed and diverse marine fishes living in tropical America (the Central Western Atlantic and Central Eastern Pacific), no fossil skeletons of Lutjanidae are reported from the Neogene. Here we describe the first specimens of Lutjanidae from the Chagres Sandstone Member of the late Miocene Chagres Formation, located on the Panamanian Caribbean coast. The skull and the postcranial bones of the specimen indicate that it represents an undescribed species of the genus Etelis. The new taxon is characterized by a moderately deep skull with dorsal surface slanted 29 ͦ relative to the horizontal axis, a large orbit, an opercle with a distal margin forming a wide spine, a posterior margin of the preopercle that is serrated without prominent spines, premaxilla and dentary with a single row of dental alveoli. The mouth is slightly oblique, and the body is elongate and slender. The dorsal fin aligns with the pectoral fins, while the pelvic fin is short and does not reach the anal fin. Oceanic water interchange and species dispersal associated with marine currents flowing eastward through the Central American Seaway appear to have driven the diversification of the American Lutjanidae prior to the complete closure of the Panama Isthmus. The palaeoceanographic changes driven by this geological event triggered a faunal turnover that shaped the extant marine diversity in the Caribbean. The newly described lutjanid is associated to a markedly bathyal (200–500 m) archipelagic and interoceanic seaway strait in central Panama (the Last Interoceanic Central American Deep Strait, LICADS).

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DOI: 10.1186/s13358-025-00397-y

Authors: Amane Tajika, Takahiro Iida, Ryoji Wani, Neil Landman, Kenji Ikuno, Christian Klug

Abstract: Phenotypic intraspecific variation of organisms is essential for evolution and, thus, has the potential to provide crucial insights into evolutionary dynamics. Additionally, ontogeny is often intricately linked with the evolutionary trajectories of organisms. In this study, we explore the relationship between the magnitude and ontogenetic pattern of intraspecific variation, and the interrelationships of organisms, their geographic distribution, and species duration. We analyzed the intraspecific variation in the whorl expansion rate (WER) of several Late Cretaceous ammonoid species, including Hypophylloceras ramosum, Phyllopachyceras ezoense, Gaudryceras tenuiliratum, Tetragonites glabrus, T. popetensis, Damesites damesi, Tragodesmoceroides subcostatus, Subprionocyclus minimus, Yezoites puerculus (all from Hokkaido, Japan), as well as Scaphites whitfieldi and Hoploscaphites comprimus (both from North America). Our results reveal a weak to moderate, negative correlation between the magnitude of intraspecific variation and geographic distribution. The correlation between intraspecific variation and species duration is weak. Notably, scaphitid and phylloceratid ammonoids exhibit a higher degree of intraspecific variation compared to other species, although no significant differences are apparent within each family. Additionally, scaphitid species from both Japan and North America display similar ontogenetic patterns of intraspecific variation. Hypophylloceras ramosum exhibits a pattern of intraspecific variation, differing from other normally coiled ammonoids. In other taxa, the pattern among species cannot be distinguished. These discoveries suggest that intraspecific variation, geographic distribution, and species duration are, at least, not positively correlated. However, contrary to previous studies, our data suggest a potential link between intraspecific variation and the interrelationships of species (relative phylogenetic position). Further research involving the analysis of more taxa, multiple morphological parameters examined over longer ontogenetic stages, and the development of a robust phylogenetic hypothesis are necessary to better understand these associations.

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DOI: 10.1186/s13358-025-00383-4

Authors: Martin Ebert, Adriana López-Arbarello

Abstract: The osteology and the systematic position of Caturus enkopicaudalis sp. nov. a fossil fish from the marine Upper Jurassic of Southern Germany, are studied in details. The characters of the skull, the general morphology and some features of the caudal skeleton strongly support the referral of this fish to the family Caturidae within the order Amiiformes. The new species belongs to the genus Caturus having a slender rod like maxilla; a high number of branchiostegal rays; block-like ural neural arches. Caturus enkopicaudalis differs from the other species of the genus mainly in the shape of the caudal fin, which is double emarginate with a central plateau; multiple small ganoin scales covering the anterior part of the caudal fin and the significantly higher number of scales rows.

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DOI: 10.1186/s13358-025-00386-1

Authors: Andrea Guerrero, Alberto Cobos, Adán Pérez-García

Abstract: Helochelydridae represents an abundant and diverse clade of basal terrestrial turtles (stem Testudines), known from the Late Jurassic to the Late Cretaceous of both Europe and North America. Despite their relatively well-documented fossil record, no pathology in a member of this lineage has been documented so far. This study presents the first documented case of a pathological condition in a helochelydrid turtle, Plastremys lata, observed in the shell of a relatively complete skeleton from the lower Albian deposits of the Spanish Santa María Quarry (Teruel Province). The lesion, located on the visceral surface of the left plastral bridge, consists of a well-defined osseous outgrowth with a central depression. The specimen was analyzed through both superficial macroscopic examination and computed tomography (CT) scanning to assess the internal structure of the anomaly. The lesion is identified as the result of a non-traumatic pathological process, potentially associated with an inflammatory bone response. This find expands the paleopathological record of Cretaceous turtles and provide new insights into the health and biological responses to environmental stressors in helochelydrids.

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DOI: 10.1186/s13358-025-00395-0

Authors: Guilherme Hermanson, Serjoscha Evers

Abstract: Ontogenetic shell shape changes of turtles are often only documented for individual species. It is currently unclear how shell shape changes during ontogeny across species, if there are common trends, and at what point in ontogeny individuals reach their adult morphology. Inspired by questions of whether some morphologies are too juvenile to be included into macroevolutionary studies of shell shape, we develop ontogenetic shell shape curves based on landmarked 3D shell shapes of turtles. Species-specific allometric shape regressions confirm that turtles show marked ontogenetic shell shape change. Geometric morphometric analysis shows that juvenile turtles have rounded shells, and ontogenetic differentiation between species increases adult turtle disparity. Disparity analysis indicates that juvenile shells across turtle clades are more similar than adult shapes, suggesting an important role of developmental constraints on early turtle shell shape, and possible adaptive post-natal ontogenetic changes that produce the observed adult shell shape disparity. Ontogenetic shell shape curves indicate when turtles converge onto adult morphologies, here quantified as 85% the distance between juvenile shape and maximum size adult shape. This happens at about 65% of the species-specific maximum carapace sizes. Sexual shell shape dimorphism is comparatively low across turtles even in the presence of pronounced sexual size dimorphism. These preliminary results provide guidance for studying shell shape macroevolution, but need to be scrutinized further in the future by data addition.

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DOI: 10.1186/s13358-025-00385-2

Authors: Yuzheng Ke, Zhongye Shi, Haiyan Tong, Bicheng Li, Yunfei Zhang, Fenglu Han, Walter Joyce

Abstract: Nanhsiungchelys, the type genus of Nanhsiungchelyidae, is an extinct turtle taxon that lived during the Late Cretaceous in southern China. Despite having a relatively abundant fossil record, the plastral morphology of Nanhsiungchelys is not well understood. Here, we describe a large specimen of Nanhsiungchelys with an associated skull and shell (SNHM 1558) from the Upper Cretaceous of Nanxiong Basin, China. The skull of SNHM 1558 is similar to that of Nanhsiungchelys yangi, but the carapace bears a pair of stick-like anterolateral processes. For this reason, we tentatively refer SNHM 1558 to Nanhsiungchelys cf. yangi. A concave plastron and a narrower posterior lobe indicate that SNHM 1558 may be a male. Nanhsiungchelys spp. was previously regarded as the most advanced taxa of Nanhsiungchelyidae, but some morphological characteristics suggest plesiomorphic similarities with the outgroup Adocus spp. A phylogenetic analysis using Adocus spp. as the outgroup suggests that Nanhsiungchelys spp. and Anomalochelys angulata form a monophyletic group at the base of Nanhsiungchelyidae. However, this phylogenetic result is not conclusive, as Nanhsiungchelys spp. is found deeply nested within the tree when Sinaspideretes wimani is employed as the outgroup.

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DOI: 10.1186/s13358-025-00375-4

Authors: Tyler Lyson, Holger Petermann, Salvador Bastien, Natalie Toth, Evan Tamez-Galvan, Sadie Sherman, Walter Joyce

Abstract: Isolated pan-chelydrid turtle shell fragments are common in Late Cretaceous and early Paleocene sediments across western North America, but more complete and associated specimens are rare, obfuscating our understanding of the group’s early evolution. Here we describe a new genus and species, Tavachelydra stevensoni, of stem-chelydrid turtle from the early Paleocene of the Denver Formation (Danian, Puercan I and II) of Colorado based on complete shells, associated pelvic material, and referred cranial material. Our phylogenetic analysis places T. stevensoni as the immediate sister to crown chelydrids based on, among others, a purely ligamentous attachment of the plastron and carapace. The costiform process of the nuchal, an important character complex in chelydroid turtles, shows variation in either ending in peripheral II or III. The T. stevensoni material was mostly found in laminated fine-grained deposits, suggesting this taxon inhabited ponded-water environments. The referred cranial material shows broad triturating surfaces indicating a durophagous diet, further underscoring durophagy as an important feeding strategy during the early Paleocene.

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DOI: 10.1186/s13358-025-00382-5

Authors: Ethan Mooney, Tea Maho, Dylan Rowe, Diane Scott, Robert Reisz

Abstract: Ontogeny and patterns of growth provide crucial insights into the evolution of dinosaurs and their biology, however, ontogenetic changes of the postcranial skeleton are generally poorly known and restricted to few species. Here, we report on the discovery of embryonic, eggshell, and hatchling material of the Early Jurassic sauropodomorph Massospondylus and provide new insights into the early life stages of early-diverging sauropodomorphs. The embryos described here represent a more advanced developmental stage than previously known embryonic materials and together show eggshells with progressive degrees of resorption correlating to embryonic development. The prominent “thumb” typical of early-diverging sauropodomorph dinosaurs also appears to be precociously ossified and ontogenetically variable. Together, these new Massospondylus embryos and hatchling indicate a quadrupedal posture and the resulting growth trajectory points to an important ontogenetically influenced ecological shift predicated on a continuum of locomotory dependent postural change, from obligate quadrupeds to obligate bipeds. Other Late Triassic and Early Jurassic sauropodomorph dinosaurs known from few ontogenetic stages also fit well on the extensive growth trajectory of Massospondylus with only modest variations in skull, neck, and limb proportions. This generally conservative body plan of early-diverging sauropodomorphs likely suggests a similar postural change for the early members of this large clade that preceded the obligate quadruped sauropods.

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DOI: 10.1186/s13358-025-00369-2

Authors: Jéhan Le Cadre, Jörg Hammel, Roland Melzer, Megan Short, Sofia Arce

Abstract: Amber resin is known for its exceptional preservations thanks to quick encapsulation of animals and plant material. Fast encapsulation not only helps preserve detailed organisms, but it also offers a glimpse into “frozen behaviors” from up to hundreds of million years, which provide information into the configuration of past ecosystems. We here investigated a syninclusion preserved in Baltic amber (~40 mya) consisting of a fossilized bristly millipede and two mite specimens, located in close proximity to the millipede’s ventral side. The two mites are representatives of Glaesacarus rhombeus, a frequently reported species of mite in Eocene amber whose lineage is considered to be now extinct. The bristly millipede is a female adult identified as a representative of Polyxenus. The specimen exhibits remarkable morphological similarities to the extant species Polyxenus lagurus, indicating the possibility of P. lagurus thriving since the Eocene. The striking persistence of morphological traits over millions of years suggests a stable ecological niche and effective adaptive strategies in Polyxenus. This unexpected association sheds new light on the ecosystem of Eocene forests and the potential effectiveness of defensive mechanisms, already present at that time, since one of the two mites is touching and seemingly surrounded by the posterior defensive setae of the millipede. Together, these findings enhance our understanding of the life of fossil Polyxenida and the evolutionary stability of Polyxenus, highlighting their long-term evolutionary resilience and success.

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DOI: 10.1186/s13358-025-00380-7

Authors: Sreepat Jain, Günter Schweigert

Abstract: Blaschkeiceras Zeiss, a rare Tithonian (Upper Jurassic) ammonite genus is now recorded for the first time from the Jaisalmer Basin of western India. Blaschkeiceras schoepflini (Blaschke) (M) is documented from the Bhadasar Formation (Jaisalmer Basin) associated with Virgatosphinctes denseplicatus (Waagen) (M) and Virgatosphinctes communis Spath (M). Jaisalmer occurrence dates from the local Oppeli Subzone, Denseplicatus Zone and is correlated with the Standard Tethyan late Tithonian Microcanthum Zone. A brief interval of rising sea level during the Microcanthum Zone probably resulted in the rapid dispersal/migration/exchange of several pandemic taxa such as Corongoceras, Micracanthoceras, Durangites, Himalayites and Blaschkeiceras into western India, aided by temperature-control due to the palaeolatitudinal position of localities (i.e., subtropical regions on either side of the equator; ~ 35° north and south).

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DOI: 10.1186/s13358-025-00392-3

Authors: Yi-Lu Liaw, Chih-Kai Chuang, Cheng-Hsiu Tsai

Abstract: The Taiwan waters (western North Pacific) include five sea turtle species without an associated fossil record. Here, we describe the first fossil sea turtle from Taiwan. This fossil material is a partial hypoplastron from the uppermost Yuching Shale in Tainan. The preserved morphology of this partial hypoplastron shows a slightly curved medial margin, a deep lateral notch, and a wide sutural anterior margin, indicating a taxonomic affinity to the genus Caretta. In comparison with extant Caretta, the preserved hypoplastral width at the sutural level (130.85 mm) suggests that this fossil belongs to an old subadult cf. Caretta. In addition, we also analyzed fossil foraminifera from the matrix of this hypoplastron, suggesting that the depositional environment was a continental shelf no more than 100 m deep. We further examined the nannofossils and found more than 200 calcareous nannofossils, including index fossils, such as Pseudoemiliania lacunosa, Helicosphaera sellii, and large Gephyrocapsa sp. (> 5.5 μm), corresponding to NN19a nannofossil biozone (Early Pleistocene in age). Given the first occurrence of the large Gephyrocapsa sp. and the last occurrence of Helicosphaera sellii, we narrowed down the age of this Pleistocene sea turtle from Taiwan to 1.57 to 1.28 million years ago. Our discovery of this Pleistocene sea turtle fossil represents not only the first cheloniid fossil in Taiwan but also the first well-dated fossil sea turtle from the global Pleistocene. The Taiwan waters during the Early Pleistocene may be a paleo-foraging ground for cf. Caretta, and future fieldwork and analysis should reveal a more detailed evolutionary history of sea turtles in the North Pacific. Our results also highlight the potential for more paleontological progress from Taiwan.

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DOI: 10.1186/s13358-025-00388-z

Authors: Vladimir Nikolov, Polina Pavlishina, Docho Dochev, Stephen Brusatte

Abstract: The Upper Cretaceous European vertebrate fossil record has improved significantly in the past three decades but there still remain chronostratigraphic and geographic gaps, which obscure our understanding of the paleobiogeography and evolution within the insular environments of the Late Cretaceous European Archipelago. Recently, a new vertebrate locality of late Santonian–early Campanian age was discovered in westernmost Bulgaria, promising to fill some of these gaps. Here, we use a multidisciplinary approach involving palynology, paleontology and paleohistology to investigate aspects of the paleoecology and taphonomy of this new locality and to provide preliminary information on its taxonomic contents. Palynomorph data shows that the flora was dominated by angiosperms of the Normapolles group with subordinate presence of ferns and only rare gymnosperms. The association of the pollen taxa Krutzschipollis crassus and K. spatiosus supports latest Santonian to early Campanian age for the vertebrate-bearing strata. The floral composition and especially a number of fern spore humidity indicators imply the existence of a generally humid subtropical climate, with some seasonal droughts. Using palynofacies analysis, we infer a coastal, proximal shelf to oxidated deltaic or lagoonal depositional environment for the examined sedimentary succession. The locality has so far yielded 250 vertebrate specimens collected from eight strata. There are at least seven clades present, including lamniform sharks, lepisosteid gars, amphibians, turtles, crocodylomorphs, ornithopod and titanosaur dinosaurs, and possibly pterosaurs. Semi-aquatic and aquatic animals dominate the assemblage. Most common are turtles (about 30% of the sample), followed by dinosaurs. Skeletal elements are disarticulated, isolated and mostly fragmentary. Fossils are not sorted by size. Many of the fossil bones show signs of abrasion and bioerosion, both micro- and macroscopically. Paleohistological data reveal that all sampled dinosaur bones belong to subadult or adult individuals. We interpret the site to be an attritional assemblage. Taxonomic comparisons with other well-known Santonian to Maastrichtian fossil assemblages from Central (Hungary and Austria) and Eastern Europe (Romania and Serbia) indicate similarities with both the Santonian Iharkút-Ajka vertebrate fauna of Hungary and the younger Haţeg Island fauna of Romania, although additional material and more precise taxonomic identification of the Bulgarian fossils is needed. Our work presents the first more in-depth look at life on land in this currently underexplored part of the Late Cretaceous European Archipelago.

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DOI: 10.1186/s13358-025-00370-9

Authors: Alfred Lemierre, Georgios Georgalis

Abstract: The Quercy Phosphorites area (Southwestern France) provides more than 200 fossiliferous localities, ranging from the early Eocene to the Early Miocene. These localities document a rich and diverse continental fauna and highlight a massive turnover in vertebrates around the Eocene–Oligocene transition. Among them, the locality of La Bouffie, from the early late Eocene (MP 17A) has yielded a diverse herpetofauna, including rare taxa for Europe (e.g., Tupinambinae). Unfortunately, most of the herpetofauna has never been described nor illustrated, leaving uncertainties regarding its true diversity. We here describe “forgotten” and undescribed specimens from La Bouffie, that pertain to pyxicephalid anurans, and gekkotan, lacertid, amphisbaenian, pleurodontan, glyptosaurid, anguine, helodermatid and palaeovaranid lizards. Among them, five taxa are identified for the first time in La Bouffie, including two new genera and species: Phosphoriguana peritechne gen. et sp. nov. (?Pleurodonta) and Cadurcopanoplos vaylatsensis gen. et sp. nov. (Glyptosauridae). Phosphoriguana peritechne gen. et sp. nov. represents the fourth pleurodontan genus from the late Eocene of Europe, highlighting the diversity of the clade on the continent prior to the “Grande Coupure”. The glyptosaurine glyptosaurid Cadurcopanoplos vaylatsensis gen. et sp. nov. represents only the second late Eocene glyptosaurine from Europe, differing from Placosaurus in having a cranial osteoderm pattern reminiscent of early Eocene glyptosaurines, like Sullivanosaurus; it therefore suggests a higher diversity of this group in the late Eocene. A review of the herpetofauna of La Bouffie identifies at least 18 illustrated and formally described taxa, while other 8 need to be properly reassessed, as the latter have only been so far briefly mentioned. This renders La Bouffie one of the most diverse late Eocene localities in Europe.

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DOI: 10.1186/s13358-025-00373-6

Authors: Alessandro Lania, Ben Pabst, Torsten Scheyer

Abstract: Non-sauropodan sauropodomorphs represented the most abundant and diverse herbivore component of the Gondwanan continental paleoecosystems during the Late Triassic. Nonetheless, a constantly increasing diversity has been recovered also from Laurasian formations, such as the Klettgau Formation, which is best exposed at the Gruhalde clay pit (Tonwerke Keller AG) in Frick, Canton Aargau, Switzerland. Despite being renowned for mass-accumulation horizons of the plateosaurid Plateosaurus trossingensis, a new fossiliferous layer was recently discovered above the “Plateosaurus bonebeds”, yielding the holotype of the neotheropod Notatesseraeraptor frickensis as well as several partial articulated skeletons of an unknown sauropodomorph. The complete craniomandibular anatomy of an articulated skull, SMF 13.5.37, belonging to a partial skeleton, SMF 13.5, referred to this new latest Norian sauropodomorph from the Klettgau Formation is here presented. Micro-computed tomography scans (µCT) as well as segmentation techniques were employed in order to examine inaccessible craniodental features of the snout of the specimen under study. The osteological investigation and the anatomical comparison with related taxa unveiled a unique mosaic-like combination of plesiomorphic and apomorphic craniomandibular features, implying that the cranial anatomy of SMF 13.5.37 is transitional between non-massopodan plateosaurian and massopodan sauropodomorph morphologies, similarly to the Argentinian Coloradisaurus brevis from the mid-to-late Norian of the Los Colorados Formation. An intermixed craniomandibular condition is also reflected in the phylogenetic results, which resolve SMF 13.5.37 as a basal massopodan, branching out either at the first or third node of Massopoda, representing the first Laurasian non-sauropodiform massopodan. Even though the evolutionary trend towards a complete massopodan-like architecture needs to be further tested with the study of the postcranium, SMF 13.5.37 unequivocally represents the skull of a new massopodan sauropodomorph taxon from Switzerland, shedding light on a more diversified herbivorous dinosaurian paleofauna from the Norian comparable to those of South America and Africa, as it represents the fourth officially recognized non-sauropodan sauropodomorph along with Plateosaurus trossingensis, Gresslyosaurus ingens and Schleitheimia schutzi.

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DOI: 10.1186/s13358-025-00381-6

Authors: Vojtěch Kovář, Oldřich Fatka

Abstract: A fossil interpreted as a long-legged lobopodian animal (Hallucigenia? sp.) is described from the middle Cambrian (Miaolingian) Jince Formation of the Příbram–Jince Basin (Barrandian area, Czech Republic). The fossil shows a long vermiform trunk, at least twenty-five long thin lobe-like appendages indicating the ventral side, and the bases of at least 12 thin spines protruding dorsally. Palynological processing of fine-grained rock samples from ca. 100 m higher in the section yielded several tens of small carbonaceous fossils attributable to armoured lobopodians alongside wiwaxiid sclerites and additional abundant organic-walled microfossils. The Bohemian specimen and recent finds of rare lobopodians in Australia, China, and the USA, together with many occurrences of isolated spines interpreted as belonging to hallucigeniids, demonstrate that lobopodians were much more geographically widespread than previously thought. The Bohemian macrofossil is the youngest known occurrence of a hallucigeniid; this specimen and the microfossil material extend the stratigraphic range of the group within the traditional early to middle Cambrian interval.

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DOI: 10.1186/s13358-025-00374-5

Authors: Xiang Fang, Björn Kröger, Kun Liang, Qing Chen, Jiaqi Song, Lan Jiang, Yaoyan He, Chenggang Wang, Xiongwei Zeng, Hao Liu, Kai Wei, Fafu Wu, Wenkun Qie

Abstract: The present paper describes the latest cephalopod fauna from the Upper Ordovician in the Anti-Atlas region, Morocco. Two species are reported herein belonging to two genera including one new species, Tafadnatoceras elfechtense sp. nov. and Isorthoceras sp.; the latter of which marks the first occurrence of the genus in Morocco. The discovery extends the distribution of late Katian cephalopod faunas globally, correlative with other high-latitude cephalopod faunas such as those from the Zagros region of Iran. After the evolutionary peak of the Great Ordovician Biodiversification Event in the Middle to early Late Ordovician, a marine ecosystem crisis led to a decline in biodiversity afterwards. Although the cephalopods continued to flourish in low-latitude regions, the palaeogeographic differentiation was observed in the Anti-Atlas region, where the faunas in the high-latitude region experienced a significant decline. The pattern aligns with the changes in the latitudinal diversity gradient from the Middle to Late Ordovician. Furthermore, the distributions of the cephalopod faunas in the Late Ordovician may have been influenced by the emergence of the high-latitude cold current.

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DOI: 10.1186/s13358-025-00376-3

Authors: Jorge Domingo Carrillo-Briceño, Iwan Stössel, René Kindlimann, Christian Klug

Abstract: The hybodontiform shark-like Strophodus was a large durophagous predator with highly specialized crushing-type dentition that mainly inhabited Mesozoic marine environments for more than 130 million years, with a fossil record spanning from the Middle Triassic to the Lower Cretaceous. Strophodus was a geographically widespread taxon with 13 species reported from Africa, Asia, Europe, India and South America. Here, we describe a new species of Strophodus, which we name Strophodus timoluebkei sp. nov. based on three teeth from the same individual in semi-articulated position. The holotype was collected in the Prealpine Sulzfluh Limestone Formation (Middle Oxfordian to Late Tithonian), Central Switzerland. Strophodus timoluebkei sp. nov. currently is the only vertebrate species reported from this geological unit, and its presence suggests that this durophagous shark likely played an important role as predator of the invertebrate fauna in this ancient Tethyan tropical coastal ecosystem. The new discovery sheds additional light onto the hybodontiform paleodiversity during the Upper Jurassic.

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DOI: 10.1186/s13358-025-00378-1

Authors: Qing Yang, Lida Xing, Fangpeng Du, Qiyan Chen, Hendrik Klein, Anthony Romilio, Yufei Jin, Lin Liu, Juan Qi, Ming Zhao, Xi Chen, Ya Zhao, Lixin Wei, Yang Wan

Abstract: In recent years, continuous discoveries of dinosaur-dominated body fossil and ichnofossil assemblages have been made in northwestern China, which has gradually enriched the understanding of the inland faunas of East Asia during the late Early Cretaceous. The Yaoshan area, located at the northeastern edge of the Liupanshan Basin (Central Ningxia) offers valuable insight into the ancient ecosystem and sedimentary conditions of the region. This paper presents the discovery of Early Cretaceous dinosaur tracks from the Madongshan Formation at the Yaoshan site. The dinosaur tracks discovered at the Yaoshan site include those from small sauropods (majority of pes length < 25 cm) and small ?bipedal dinosaur (9.3 to 20.4 cm in pes length), with theropod, ornithopod, and even sauropod affinities of varying sizes. The findings not only contribute to our understanding of the fauna that inhabited north-western China during the late Early Cretaceous, but also shows the interactions between the dinosaurs and microhabitats.

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DOI: 10.1186/s13358-025-00384-3

Authors: Lea Numberger-Thuy, Manuela Aiglstorfer, Dominique Delsate, Susanne Feist-Burkhardt, Stefan Gräbenstein, Philipe Havlik, Sylvie Régnier, Thomas Servais, Ben Thuy

Abstract: The Triassic-Jurassic (T/J) boundary witnessed one of the five major mass extinctions during the Phanerozoic, paving the way towards the evolution of modern ecosystems. However, the study of biotic change during this interval is hampered by the scarcity of outcrops exposing the T/J-boundary without major interruptions or abrupt facies change. Here, we present a previously undocumented succession of Rhaetian (Upper Triassic) to Hettangian (Lower Jurassic) strata, exposed on two sections along the banks of the river Prüm near the town of Irrel, Rhineland-Palatinate, Germany. The new succession holds an unusual palaeogeographic position squeezed between the Rhenish and London Brabant (including the Ardennes) massifs, thus filling a gap in the T/J-boundary record of the Central European Basin. It includes some unusual facies such as a thick and highly fossiliferous, conglomeratic bonebed close to the top of the middle Rhaetian and bituminous black claystones in the middle Hettangian. Finally, it stands out in yielding well preserved fossils of taxa that are rare or undocumented in the region. We provide a comprehensive account of the lithostratigraphy of the new succession and assess its biostratigraphic framework using ammonite, ostracod and palynomorph occurrences.

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DOI: 10.1186/s13358-025-00371-8

Authors: Bernard Lathuilière

Abstract:

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DOI: 10.1186/s13358-025-00359-4

Authors: Werner Schwarzhans, Aleksandre Bannikov

Abstract: Otolith finds in situ are important for connecting the independent data sets of articulated fish skeletons and isolated otoliths in the fossil record. Here we describe an otolith in situ retrieved from a skeleton of the stromateid Pinichthys shirvanensis Bannikov, 2021, which was collected from the Tarkhanian (Langhian, Middle Miocene) from the prolific Pshekha River locality in the Krasnodar Region of the northern Caucasus, Russia. It represents the first find of an otolith in situ made in a fossil stromateoid skeleton. The extracted otolith is compared to fossil otolith-based species allocated to the genus Pampus. One of these species is being reallocated in the process to Pinichthys: Pinichthys steurbauti (Schwarzhans, 1994) from the late Oligocene to early Middle Miocene in the North Sea Basin.

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DOI: 10.1186/s13358-025-00379-0

Authors: Richard Fariña, Elspeth Hayes, Luis Lemoine, Richard Fullagar, P. Tambusso, Luciano Varela

Abstract: Several sites in the Americas are proposed to have evidence of human occupation before the Last Glacial Maximum (LGM). The timing of human colonisation of the Americas is a matter of debate due to its intrinsic interest, but also because of the implications of that arrival for the extinction of the megafauna. Here, we study a notable indentation in the right calcaneus of a giant extinct ground sloth Lestodon armatus from the Arroyo del Vizcaíno site, Uruguay, dated to ~ 33 cal kyBP. We use a combination of 3D CT-scan modelling, high-resolution silicone casting, and microscopic wear and residue analysis to describe the morphology of the lesion, its associated residues, and the possible mechanisms behind its formation. Considering the indentation’s features, including its shape, depth, and the presence of organic residues, we argue that it could have been created by a penetrating object with a rounded tip, possibly a bone, ivory or hardened wood tip attached to a shaft. This evidence contributes to discussions on the dates of human arrival in South America and the potential interactions with the megafauna.

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DOI: 10.1186/s13358-025-00358-5

Authors: Yann Rollot, Mohamed Abdelgawad, Mohamed Hamdan, Ahmed El-Barkooky, Safiya Hassan, Walter Joyce

Abstract: Although trionychians have a rich fossil record, much of their fossil diversity is known from the Cretaceous and Paleogene, and little is known about their evolutionary history in the Neogene. We here describe cranial and shell material of trionychians from the Early Miocene Moghra Formation of Egypt that we attribute to a new carettochelyid taxon, Allaeochelys meylani sp. nov., and to the Trionyx lineage. Allaeochelys meylani sp. nov. fills a temporal gap between previously described taxa and exhibits a series of unique features, including greatly thickened cranial bones, a broad bony wall posterior to the orbit, a large fossa formed by the maxilla and premaxilla at the anterior third of the triturating surface, and a medial process on peripheral II. Allaeochelys meylani sp. nov. also documents the oldest occurrence of Carettochelyidae on the Afro-Arabian continent, while the Trionyx material reported herein provides unambiguous evidence for the presence of this lineage on the Afro-Arabian continent no later than the Early Miocene.

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