Quantifying the variation in body proportions within Crocodylomorpha

• Grant number: 23/13687-6
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: June 12, 2024
• End date: March 12, 2025
• Field of knowledge: Biological Sciences - Zoology - Paleozoology
• Principal Investigator: Max Cardoso Langer
• Grantee: Ana Laura da Silva Paiva
• Supervisor: Philip Mannion
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Institution abroad: University College London (UCL), England
• Associated to the scholarship: 22/02249-5 - Quantifying differences in body proportions in Crocodylomorpha, BP.DR

Abstract

With a rich fossil record that dates back to the Late Triassic, Crocodylomorpha exhibits a remarkable diversity of body plans, which makes the group an excellent study system for macroevolutionary investigations documenting phenotypic changes through time. This morphological disparity includes significant variation in cranial and postcranial morphology, usually associated with different ecological habitats and diets. Changes in body size are also noteworthy, ranging from species less than one meter, such as some "sphenosuchians", to giant forms, such as Machimosaurus and Purussaurus, more than seven metres long. Similarly, body proportions (i.e., relative skull size) vary significantly between major crocodylomorph clades, possibly also in association with ecology/habitat; however, this has never been quantitatively tested. This research project intends to quantify the variation in body proportions among crocodylomorphs, collecting cranial and femoral measurements from a wide range of specimens to represent skull size in relation to the body. These will be mapped on to a time-calibrated phylogenetic tree of the group, allowing the identification of major evolutionary shifts. Finally, regression models will be used to investigate possible biotic and abiotic drivers. The research will be conducted at University College London (UCL), in the UK, more specifically at the Vertebrate Palaeontology Lab. The Lab is led by Dr. Philip Mannion, an expert in crocodylomorphs and macroevolutionary analyses. Besides the scientific expertise and structure of the Lab, the proximity to important collections, including the Natural History Museum, London, will be also highly beneficial for the data collection stage of the project.