Pre-therian synapsid forelimb musculature + metriorhynchid vertebra from Chile + temnospondyl from Carboniferous of France + giant crocodylian bite marks from Miocene of Colombia (free pdfs)
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Ben Creisler
Aug 17, 2026, 1:07:59 PMAug 17
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Ben Creisler
Recent tetrapod papers:
P. J. Bishop & S. E. Pierce (2026)
Reconstructions of forelimb musculature in extinct pre-therian synapsids
Bulletin of the Museum of Comparative Zoology 164(2): 145-184
doi: https://doi.org/10.3099/MCZ85.1
https://bioone.org/journals/bulletin-of-the-museum-of-comparative-zoology/volume-164/issue-2/MCZ85.1/RECONSTRUCTIONS-OF-FORELIMB-MUSCULATURE-IN-EXTINCT-PRE-THERIAN-SYNAPSIDS/10.3099/MCZ85.1.full
Previously, the authors published a framework for phylogenetically informed reconstruction of appendicular musculature in extinct synapsids. In the present study, this framework is used to rigorously infer the arrangement of muscles in the forelimb of five exemplar taxa—Dimetrodon milleri (“pelycosaur”), Oudenodon bainii (dicynodont), Lycaenops ornatus (gorgonopsian), Massetognathus pascuali (nonmammalian cynodont), and Vincelestes neuquenianus (stem therian)—that capture the evolutionary transformation from basal synapsids to crown therians. Where direct osteological correlates of muscle attachments were unavailable, maximum parsimony was used to infer the phylogenetically most plausible arrangement for a given muscle. The muscle maps presented here for each taxon, detailing origins and insertions of all forelimb muscles proximal to the wrist joint, largely concur with prior, but superficial, reconstructions, but also provide additional nuance and refinement. These will aid the interpretation of fossil material in the future, especially fragmentary remains of related species, and provide a foundation for functional analysis of the appendicular skeleton and its evolution.
Oscar E. Wilson, Jorge W. Moreno-Bernal, Catalina Suarez, Frank Cardozo Tovar, Andrés Vanegas, Rubén Vanegas, Ethan A. Shirley, Patricia A. Holroyd & John-Paul Zonneveld (2026)
Physical evidence of crocodylian predation on ungulates in the Middle Miocene of Colombia
Journal of Vertebrate Paleontology: e2701154
doi: https://doi.org/10.1080/02724634.2026.2701154
https://www.tandfonline.com/doi/full/10.1080/02724634.2026.2701154
Free pdf:
https://www.tandfonline.com/doi/epdf/10.1080/02724634.2026.2701154
South American fossil mammalian assemblages contain a relatively low ratio of predators to prey. Consequently, large non-mammalian predators occupy a major ecological role. In the Middle Miocene assemblage of La Venta, Colombia, crocodyliforms have been previously proposed as the most significant predators of large mammals. Here we present ichnological evidence for predation by giant crocodylians of three large ungulates from La Venta: Pericotoxodon platignathus, Xenastrapotherium kraglievichi, and Granastrapotherium snorki. A partial cranium of P. platignathus preserves a large, bisected circular puncture mark. Part of a distal femur of P. platignathus includes a series of semicircular puncture marks and smaller pits. Two astrapothere mandibles contain multiple puncture marks associated with significant deformation. In all cases, the most likely predator is interpreted as Purussaurus, based on the size and shape of the puncture marks and the presence of significant deformation to the cortical bone. The recognition of the ichnotaxon Knethichnus parallelum in a Xenastrapotherium mandible probably relates to a separate scavenging event by a ziphodont crocodyliform, likely Langstonia huilensis. The similarities between the trace fossils associated with Purussaurus predation and bite marks produced by modern crocodiles support the use of modern crocodiles as analogues to interpret the ecology of Miocene giant crocodylians.
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Free pdf:
P. J. Bishop & S. E. Pierce (2026)
Reconstructions of forelimb musculature in extinct pre-therian synapsids
Bulletin of the Museum of Comparative Zoology 164(2): 145-184
doi: https://doi.org/10.3099/MCZ85.1
https://bioone.org/journals/bulletin-of-the-museum-of-comparative-zoology/volume-164/issue-2/MCZ85.1/RECONSTRUCTIONS-OF-FORELIMB-MUSCULATURE-IN-EXTINCT-PRE-THERIAN-SYNAPSIDS/10.3099/MCZ85.1.full
Previously, the authors published a framework for phylogenetically informed reconstruction of appendicular musculature in extinct synapsids. In the present study, this framework is used to rigorously infer the arrangement of muscles in the forelimb of five exemplar taxa—Dimetrodon milleri (“pelycosaur”), Oudenodon bainii (dicynodont), Lycaenops ornatus (gorgonopsian), Massetognathus pascuali (nonmammalian cynodont), and Vincelestes neuquenianus (stem therian)—that capture the evolutionary transformation from basal synapsids to crown therians. Where direct osteological correlates of muscle attachments were unavailable, maximum parsimony was used to infer the phylogenetically most plausible arrangement for a given muscle. The muscle maps presented here for each taxon, detailing origins and insertions of all forelimb muscles proximal to the wrist joint, largely concur with prior, but superficial, reconstructions, but also provide additional nuance and refinement. These will aid the interpretation of fossil material in the future, especially fragmentary remains of related species, and provide a foundation for functional analysis of the appendicular skeleton and its evolution.
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Free pdf:
Daniel Bajor, Jhonatan Alarcón-Muñoz, Omar Vicencio-Campos & David Rubilar-Rogers (2026)
An incomplete metriorhynchid (Crocodylomorpha: Thalattosuchia) caudal vertebra from the Late Jurassic of northern Chile, and comments on South American thalattosuchian paleobiogeography
[Una vértebra caudal incompleta de metriorrínquido (Crocodylomorpha: Thalattosuchia) del Jurásico Tardío del norte de Chile, y comentarios sobre la paleobiogeografía de los talattosuquios de Sudamérica]
Boletín Museo Nacional De Historia Natural 75(2): 5–22.
doi: https://doi.org/10.54830/bmnhn.v75.n2.2026.1035
https://boletinmnhn.cl/index.php/ojs/article/view/1035
An incomplete metriorhynchid (Crocodylomorpha: Thalattosuchia) caudal vertebra from the Late Jurassic of northern Chile, and comments on South American thalattosuchian paleobiogeography
[Una vértebra caudal incompleta de metriorrínquido (Crocodylomorpha: Thalattosuchia) del Jurásico Tardío del norte de Chile, y comentarios sobre la paleobiogeografía de los talattosuquios de Sudamérica]
Boletín Museo Nacional De Historia Natural 75(2): 5–22.
doi: https://doi.org/10.54830/bmnhn.v75.n2.2026.1035
https://boletinmnhn.cl/index.php/ojs/article/view/1035
An incomplete isolated thalattosuchian vertebra (SGO.PV.1092) collected near Cerritos Bayos is described, and identified as a mid-caudal vertebra of a metriorhynchid (cf. Metriorhynchidae gen. et sp. indet.). The specimen represents the first three-dimensionally preserved caudal element of this group of pelagic predators from the Jurassic of Chile to be described and figured. It most likely originates from Oxfordian (lower Upper Jurassic) levels of the Cerro Campamento Formation. The paleobiogeographic relevance of incomplete and isolated thalattosuchian axial fossils from South America is commented on, and the implications of the apparent absence of Teleosauroidea in the Jurassic fossil record of the continent is discussed. There is currently no evidence of the metriorhynchid genus Metriorhynchus, or any teleosauroid having reached the Southeastern Pacific during this period. Given that historically they used to be considered as important faunistic elements of an Early–Middle Jurassic marine biotic interchange between the western Tethys and the western coast of South America, this lack of evidence calls the proposed pre-Oxfordian stage of the Caribbean Corridor hypothesis as an early dispersal route for Mesozoic marine reptiles into question.
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Free pdf:
Antoine Logghe, Claude Goujon, Monique Goujon, Jean-Marc Pouillon, Romain Garrouste & J.-Sébastien Steyer (2026)
The first vertebrate from the Late Carboniferous – Early Permian Graissessac Basin (Massif Central) with a new occurrence of a temnospondyl in France
Annales de Paléontologie 112(2): 102931
doi: https://doi.org/10.1016/j.annpal.2026.102931
https://www.sciencedirect.com/science/article/pii/S0753396926000182
The first vertebrate from the Late Carboniferous – Early Permian Graissessac Basin (Massif Central) with a new occurrence of a temnospondyl in France
Annales de Paléontologie 112(2): 102931
doi: https://doi.org/10.1016/j.annpal.2026.102931
https://www.sciencedirect.com/science/article/pii/S0753396926000182
A new temnospondyl specimen from the Carboniferous of the Graissessac Basin (southern France) is preliminary described here. It corresponds to the first occurrence of a vertebrate in the Graissessac Basin. The specimen consists of a partial skull articulated with the pre-sacral part of the vertebral column, ribs, scapular remains and skin patches. Yet its poor preservation limits its identification to Temnospondyli indet., even if it presents a mosaic of characters found in both dvinosaurs (short preorbital region, small orbits, a broad cultriform process anteriorly widened) and dissorophoids (elongated skull table, proportionally long and slender ribs). The specimen is identified as a possible paedomorphic adult. This specimen highlight the close resemblance between dvinosaurians and micromelerpetid dissorophoids, especially at a larval stage. In France, Carboniferous temnospondyls were known so far in the basins of Blanzy-Montceau, Commentry and Decazeville. This new discovery therefore increases the range of this group in another basin (Graissessac) and it corresponds to one of the rare Carboniferous temnospondyl found south of the Variscan Belt. It also confirms the strong dispersal of the group during the Carboniferous and the closed interconnections between the lacustrine European basins. Finally, the fact that this new fossil has been discovered by a volunteer strenghtens the role of non-institutional palaeontologists in the search of specimens important for science.
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Free pdf:
Oscar E. Wilson, Jorge W. Moreno-Bernal, Catalina Suarez, Frank Cardozo Tovar, Andrés Vanegas, Rubén Vanegas, Ethan A. Shirley, Patricia A. Holroyd & John-Paul Zonneveld (2026)
Physical evidence of crocodylian predation on ungulates in the Middle Miocene of Colombia
Journal of Vertebrate Paleontology: e2701154
doi: https://doi.org/10.1080/02724634.2026.2701154
https://www.tandfonline.com/doi/full/10.1080/02724634.2026.2701154
Free pdf:
https://www.tandfonline.com/doi/epdf/10.1080/02724634.2026.2701154
South American fossil mammalian assemblages contain a relatively low ratio of predators to prey. Consequently, large non-mammalian predators occupy a major ecological role. In the Middle Miocene assemblage of La Venta, Colombia, crocodyliforms have been previously proposed as the most significant predators of large mammals. Here we present ichnological evidence for predation by giant crocodylians of three large ungulates from La Venta: Pericotoxodon platignathus, Xenastrapotherium kraglievichi, and Granastrapotherium snorki. A partial cranium of P. platignathus preserves a large, bisected circular puncture mark. Part of a distal femur of P. platignathus includes a series of semicircular puncture marks and smaller pits. Two astrapothere mandibles contain multiple puncture marks associated with significant deformation. In all cases, the most likely predator is interpreted as Purussaurus, based on the size and shape of the puncture marks and the presence of significant deformation to the cortical bone. The recognition of the ichnotaxon Knethichnus parallelum in a Xenastrapotherium mandible probably relates to a separate scavenging event by a ziphodont crocodyliform, likely Langstonia huilensis. The similarities between the trace fossils associated with Purussaurus predation and bite marks produced by modern crocodiles support the use of modern crocodiles as analogues to interpret the ecology of Miocene giant crocodylians.
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