Shape Variations in the Endocranial Cavity of Ungulate Mammals: Exploring Major Selective Pressures on the Endocranium in Extinct Taxa, with an Emphasis on Notoungulata

• Grant number: 24/17041-6
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: July 01, 2025
• End date: June 30, 2028
• Field of knowledge: Biological Sciences - Zoology - Paleozoology
• Principal Investigator: Max Cardoso Langer
• Grantee: Santiago Ezequiel Hernández Del Pino
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

South American geographical isolation during the Cenozoic led to the evolution of an unique mammalian fauna. Among these, Notoungulata showed significant species richness and morphological diversity. Paleoproteomic and paleogenomic studies suggest a close relation between Notoungulata, Litopterna, and modern Perissodactyla, forming Panperissodactyla. Although anatomical studies about the South American Native Ungulates (SANU) are extensive, the ecological drivers of their endocranial morphology have been underexplored. This research proposal aims to examine shape variation in the endocranial cavity of ungulate mammals, focusing on SANU, particularly Notoungulata. Key objectives encompass evaluating how body mass, habitat preference, feeding behavior, and phylogeny influence the endocranial cavity shape of extant ungulates to infer SANU evolutionary processes. Using three-dimensional geometric morphometrics, this study will quantify shape variation, assess morphological integration and modularity, identify cranial cavity modules, and construct theoretical morphospaces to estimate ecological attributes in extinct taxa. Expected results include a better understanding of the ecological and evolutionary factors shaping endocranial morphology in ungulates. Additionally, this proposal will allow the development of a digital database on the endocranial morphology of SANU and the creation of educational resources for scientific outreach and science popularization.