Characterisation of deep-time body size evolutionary patterns in Testudinata

• Grant number: 19/06119-6
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: October 01, 2019
• End date: March 21, 2020
• Field of knowledge: Biological Sciences - Zoology - Paleozoology
• Principal Investigator: Max Cardoso Langer
• Grantee: Bruna de Mattos Farina
• Supervisor: Roger Benson
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Institution abroad: University of Oxford, England
• Associated to the scholarship: 18/10276-7 - Characterization of macroevolutionary patterns of body size in Testudinata, BP.MS

Abstract

Testudinata is a highly diverse clade of tetrapods in terms of both extant and extinct taxa. This is reflected on the group's remarkable ecological diversity and morphological disparity, and in particular in its great body size disparity, which may be related to the environmental transitions experienced by the group through time. In this context, phylogenetic comparative methods represent important tools to investigate the patterns and modes of evolution of phenotypic characters (e.g. body size). Previous work on turtle body size evolution focused mainly on extant taxa, neglecting important information provided by the fossil record. Thus, this project aims to fully characterize Testudinata body size macroevolutionary patterns, employing a model-fitting approach. In order to do so, we will fit to our body size data a set of different evolutionary models, based on Brownian Motion (BM) and Ornstein-Uhlenbeck (OU) processes, with single or multiple macroevolutionary regimes. Aiming at identifying deep-time evolutionary patterns, we focus on sampling as many extinct taxa as possible, from which carapace length are measured and used as a proxy for total body length. The results from our macroevolutionary analyses will then be compared to a series of abiotic (e.g. palaeotemperature) and biotic (habitat) factors that could be acting as potential drivers. (AU)