Comparison of locomotor posture in extinct crocodyliforms with modern counterparts

• Grant number: 24/10657-1
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: October 01, 2024
• End date: January 31, 2028
• Field of knowledge: Biological Sciences - Zoology - Paleozoology
• Principal Investigator: Fabiana Rodrigues Costa Nunes
• Grantee: Valerian Jean Philippe Jésus
• Host Institution: Centro de Ciências Naturais e Humanas (CCNH). Universidade Federal do ABC (UFABC). Ministério da Educação (Brasil). Santo André , SP, Brazil
• Associated research grant: 22/03099-7 - Tridimensional modeling and locomotor biomechanics in extinct vertebrates, AP.PNGP.PI

Abstract

Crocodyliformes have been known since the Late Triassic and are only represented today bycrocodilians. Despite crocodilians presenting conservative morphology, it is known that the lineage underwent postural changes that led to a transition from a more upright posture to a more sprawled one, with the anterior and posterior limbs more flexed and spread apart in relation to the body position. For the purpose of comparing these postures, 3D models of the notosuchians Araripesuchus gomesii (AMNH 24450, nearly complete specimen) and Simosuchus clarki (UA 8679, nearly complete, articulated specimen, with preservation of the pectoral girdle associated with the forelimbs, pelvic girdle, and hind limbs) will be reconstructed, finalized in their musculoskeletal constitution, and studied in terms of optimal posture and movement, as described in the stages of this project. These models will then be biomechanically compared to each other, and models of modern crocodilians (Caiman crocodilus and Paleosuchus palpebrosus) will be recorded during walking and galloping cycles. The movement patterns captured by the recordings will then be compared with those simulated by the notosuchians models in a virtual environment for comparison purposes. This project aims to develop a method for inferring the posture and gait of extinct vertebrate species using observations of current species. This method will provide additional information on the lifestyle of these species and how they fed, hunted, and traveled. (AU)