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Morphology of the maxilla informs about the type of predation strategy in the evolution of Abelisauridae (Dinosauria: Theropoda)
Articulo
Authorship:
Seculi Pereyra, E. Emanuel ; Vrdoljak, Juan E. ; Ezcurra, Martín Daniel ; González-Dionis, Javier ; Paschetta, Carolina ; Méndez, Ariel H.Date:
2025Publishing House and Editing Place:
Nature Publishing GroupMagazine:
Scientific Reports - ISSN 2045-2322Nature Publishing Group
ISSN:
2045-2322Summary *
Abelisauridae is the group of most abundant predatory dinosaurs in the Cretaceous of Gondwana, being characterized by short, ornamented skulls and strongly reduced forelimbs. Bolstered by biomechanical studies, the morphology of the skull and vertebral column of abelisaurids, have led researchers to hypothesize that Late Cretaceous forms were “specialized hunters.” Here, we use the morphology of the abelisaurid maxilla to test if its morphology is consistent with this hypothesis. Additionally, we analyze the diversity and disparity of abelisaurids maxilla in a macroevolutionary context. We quantified the maxilla shape in 17 taxa using 2D geometric morphometrics and analyzed different evolutionary scenarios and trends with phylogenetic comparative methods. The results of all the analyses (phylogenetic ordination methods, Z, and R2 comparison in phylogenetic generalized least squares, model selection, and estimated taxa-removal analysis) suggest that the hunter specialization appears during the Early Cretaceous, revealing that Cretaceous abelisaurids can be considered specialist hunters. High levels of morphological disparity in the maxilla occurred shortly after the proposed Cenomanian-Turonian faunistic turnover, which involved drastic changes in the South American terrestrial faunal assemblages. Moreover, the high evolutionary rates of the maxillary shape change in Abelisauridae supports a shift in ecological pressures or socio-sexual mechanisms, which were the main drivers of the evolution of the clade rostrum. Our study invites to analyze more osteological elements of the abelisaurid skull under a quantitative macroevolutionary framework to test our results more comprehensively. Information provided by the agent in SIGEVAKey Words
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