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Therocephalia are an important clade of non-mammalian therapsids that evolved a diverse array of morphotypes and body sizes throughout their evolutionary history. The postcranial anatomy of therocephalians has largely been overlooked, but remains important towards understanding aspects of their palaeobiology and phylogenetic relationships. Here, we provide the first postcranial description of the large akidnognathid eutherocephalianMoschorhinus kitchingiby examining multiple specimens from fossil collections in South Africa. We also compare the postcranial anatomy with previously described therocephalian postcranial material and provide an updated literature review to ensure a reliable foundation of comparison for future descriptive work.Moschorhinusshares all the postcranial features of eutherocephalians that differentiate them from early-diverging therocephalians, but is differentiated from other eutherocephalian taxa by aspects concerning the scapula, interclavicle, sternum, manus, and femur. The novel anatomical data from this contribution shows thatMoschorhinuspossessed a stocky bauplan with a particularly robust scapula, humerus, and femur. These attributes, coupled with the short and robust skull bearing enlarged conical canines imply thatMoschorhinuswas well equipped to grapple with and subdue prey items. Additionally, the combination of these attributes differ from those of similarly sized coeval gorgonopsians, which would have occupied a similar niche in late Permian ecosystems. Moreover,Moschorhinuswas the only large carnivore known to have survived the Permo-Triassic mass extinction. Thus, the subtle but important postcranial differences may suggest a type of niche partitioning in the predator guild during the Permo-Triassic mass extinction interval.
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First record of a complete humerus of Agriotherium (mammalia-ursidae) from the early-late Hemphillian of Zacatecas, Mexico
A complete humerus referred to Agriotherium is described, collected from early-late Hemphillian deposits from Zacatecas. Agriotherium is widely represented by isolated molars, mandibles, and maxillae in early-late Hemphillian faunas of Eurasia and North America. In the literature, postcranial elements are scarce and briefly described with little detail. The greatest diversity is known from the Langebaanweg quarry in South Africa; however, the only complete specimen is from Mexico. The proximal end is described, and the humerus shares similarities with the description of the distal end from South Africa, in which the medial epicondyle and crest of the lateral epicondyle are reduced, which can be considered as a limitation in the hunting of larger prey for food. This implies that Agriotherium was not strictly carnivorous but was a predator-scavenger with an omnivorous diet that included plants and fruits.
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- Award ID(s):
- 1949742
- PAR ID:
- 10438663
- Date Published:
- Journal Name:
- Revista mexicana de ciencias geológicas
- Volume:
- 40
- Issue:
- 2
- ISSN:
- 1026-8774
- Page Range / eLocation ID:
- 214-226
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.22201/cgeo.20072902e.2023.2.1738
