Affiliation:
1. Programa de Pós‐Graduação em Ecologia e Evolução da Biodiversidade, Escola de Ciências da Saúde e da Vida Pontifícia Universidade Católica do Rio Grande do Sul Porto Alegre RS Brazil
2. Museu de Ciências Naturais Secretaria do Meio Ambiente e Infraestrutura Porto Alegre RS Brazil
Abstract
AbstractAmong the living tetrapods, mammals present a unique tooth replacement pattern, diphyodonty. Therefore, studying the dentition of mammalian ancestors is relevant to a better understanding of how this remarkable feature evolved. However, little is known about the postcanine tooth replacement pattern among Triassic cynodonts. Here, we applied the nondestructive method of microcomputed tomography (microCT) to analyze the dentition of the enigmatic Upper Triassic sectorial‐toothed cynodont Charruodon tetracuspidatus (MCP 3934 PV, holotype) from the Candelaria Sequence, Santa Maria Supersequence, Brazil. The microCT‐scan data allowed visualization of the replacement dentition and roots of the functional teeth, which provided information to inform interpretations of the ontogenetic stage and taxonomy of the species. A combination of dental and mandibular traits, as well as the small size of the specimen MCP 3934 PV, suggest an early ontogenetic stage. Additionally, the specimen could potentially be an ontogenetically immature form of another taxon, or a yet unknown species of probainognathian cynodont. Therefore, Charruodon tetracuspidatus is here designated as a nomen dubium, given the challenges of maintaining the species as valid.
Funder
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Subject
Ecology, Evolution, Behavior and Systematics,Histology,Biotechnology,Anatomy