Morphological disparity of Silesauridae and Heterodontosauridae: exploring the origin of Ornithischa

• Grant number: 24/20853-2
• Support Opportunities: Scholarships in Brazil - Master
• Start date: October 01, 2025
• End date: September 30, 2026
• Field of knowledge: Biological Sciences - Zoology - Paleozoology
• Principal Investigator: Max Cardoso Langer
• Grantee: Bianca Paschoal Toller Garcia
• 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

The presented research plan aims to document patterns of morphological disparity in Silesauridae and Heterodontosauridae, clades of Dinosaromorpha without consistent phylogenetic placements. The record of the Silesauridae is restricted to the Late Triassic, from 237 to 201 million years ago, while the Heterodontosauridae were recorded between the Early Jurassic, 201 million years ago, and the Early Cretaceous, 145 million years ago. The Silesauridae are positioned outside Dinosauria by some authors and in the dinosaur lineage of the Ornithischia by others. Heterodontosauridae are consistently accepted as ornithischians, but alternatively external to Genasauria or as a sister group to Marginocephalia. With this in mind, it is proposed in this project to carry out morphological disparity analyses based on discrete characters, which will allow the construction of the morphospace of such groups, quantifying the morphological differences and similarities between them and in relation to other groups of dinosauromorphs. Finally, understanding the morphological variation of these taxa will help us understand the initial irradiation and diversification of ornithischian dinosaurs.