Palaeoneurology and palaeobiology of the dinocephalian therapsid Anteosaurus magnificus - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Acta Palaeontologica Polonica Année : 2021

Palaeoneurology and palaeobiology of the dinocephalian therapsid Anteosaurus magnificus

Résumé

Dinocephalians (Therapsida), some of the earliest amniotes to have evolved large body size, include the carnivorous Anteosauria and mostly herbivorous Tapinocephalia. Whilst the palaeoneurology of the Tapinocephalia has been investigated in Moschognathus whaitsi, that of the Anteosauria remains completely unknown. Here we used X-ray micro-Computed Tomography to study, for the first time, the palaeoneurology of Anteosaurus magnificus. Compared to Moschognathus, we reconstruct Anteosaurus as an agile terrestrial predator based on the enlarged fossa for the floccular lobe of the cerebellum and semicircular canals of the inner ear. A major difference between the two genera resides in the orientation of the braincase, as indicated by the angle between the long axis of the skull and the plane of the lateral semicircular canal. This angle is 25 degrees in Anteosaurus, whereas it is 65 degrees in Moschognathus, which suggests that the braincase of the latter was remodelled as an adaptation to head-butting. This is consistent with less cranial pachyostosis and the retention of a large canine in Anteosauria, which suggests that dentition may have been used for intraspecific fighting and display in addition to trophic interactions. The evolution of a thick skull, horns, and bosses in tapinocephalids parallels the evolutionary reduction of the canine, which lead to a shift of the agonistic function from the mouth to the skull roof, as observed in extant social ungulates. Similarly, tapinocephalians may have developed complex social behaviour.
Fichier principal
Vignette du fichier
Acta_Pal_Polonica_66_29.pdf (890.98 Ko) Télécharger le fichier
Origine Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-03723564 , version 1 (15-07-2022)

Identifiants

Citer

Julien Benoit, Ashley Kruger, Sifelani Jirah, Vincent Fernandez, Bruce S. Rubidge. Palaeoneurology and palaeobiology of the dinocephalian therapsid Anteosaurus magnificus. Acta Palaeontologica Polonica, 2021, 66 (1), pp.29-39. ⟨10.4202/app.00800.2020⟩. ⟨hal-03723564⟩
4 Consultations
72 Téléchargements

Altmetric

Partager

Gmail Mastodon Facebook X LinkedIn More