Investigating the diversity of Mesoeucrocodylia in the K-Pg event through a morphofunctional and biogeographical approach

• Grant number: 24/07676-4
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: December 01, 2024
• End date: November 30, 2026
• Field of knowledge: Biological Sciences - Zoology - Paleozoology
• Principal Investigator: Max Cardoso Langer
• Grantee: Juan Vítor Ruiz
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 20/07997-4 - Dinosaur diversity and associated faunas in the Cretaceous of South America, AP.TEM

Abstract

Although restricted in number of species, morphology, and geographic distribution, living crocodylomorph (Archosauria, Crocodylomorpha) species, the crocodiles, caimans, and gharials, represents only a fraction of their past diversity, which date back to the Triassic (~210 m.y). Crocodylomorphs diversified during the Mesozoic and, unlike other large tetrapods, did not succumb to the Cretaceous-Paleogene mass extinction event. Even though many lineages became extinct, specialized groups of Cretaceous crocodylomorphs remain present in the Cenozoic, such as the terrestrial hypercarnivores Sebecidae and the marine predators Dyrosauridae. Some recent studies sought to understand the relation between crocodylomorph diversity and extinction processes, but there are no analyses that investigated whether morphofunction (i.e., form linked to the function of a system) played a role in their survival across the K-Pg boundary. The present project aims to investigate the relations between crocodylomorph diversity in the Cretaceous-Paleogene with morphofunctional and biogeographic perspectives, focusing on the two major Mesoeucrocodylia lineages that survived the K-Pg event, Notosuchia and Neosuchia. The morphofunctional subprojects will compare the mandibular biomechanics of correlated Cretaceous and Paleogene taxa via finite element analysis and mechanical advantage, tools that allow a quantitative comparative analysis. The subproject focused on biogeography aims to understand whether the enormous diversity and broad distribution of Cretaceous Notosuchia are linked to global climate patterns. Such a multidisciplinary approach is innovative and has great potential to elucidate issues associated with the diversification of these organisms in the context of a major mass extinction.