Description of new Chelidae (Testudines, Pleurodira) fossil material from the Tremembé Formation (Oligocene), with the proposal of a new species

• Grant number: 24/22761-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2025
• End date: April 30, 2026
• Field of knowledge: Biological Sciences - Zoology - Paleozoology
• Principal Investigator: Pedro Lorena Godoy
• Grantee: Gustavo Gonçalves Barreiros
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 24/09825-7 - Characterizing diversity and evolutionary patterns of Amniota: systematics, macroevolution and paleoecology, AP.JP

Abstract

The Tremembé Formation was a lacustrine system currently inserted in the Taubaté Basin, playing a significant role in the understanding of the fauna and flora of the Brazilian Paleogene (Oligocene), with several important discoveries that contribute to a better interpretation of the environment during this rare period in the fossil records of our country. An essential piece for this contribution is the Taubaté Natural History Museum Dr. Herculano Alvarenga (MHNT), whose Testudines material hasn't been properly described, with a single work on the description of material from the Tremembé Formation still not formally published. Consequently, the diversity of Testudines in the Formation is potentially underestimated at present. One of the pieces of evidence supporting this claim comes from undescribed Testudines fossil materials from the Tremembé Formation present in the collection of the Taubaté Natural History Museum. Preliminary inspections of these materials indicate significant morphological differences between individuals. In this regard, the present project will seek to identify and describe in detail the Testudines material from the collection of the Taubaté Natural History Museum, which mainly includes an individual with a partially preserved carapace and plastron and some associated post-cranial bones, potentially a new species, as well as other materials such as shell plates and isolated bones. A morphological comparison with extinct and living species will also be carried out, enabling proper taxonomic attribution. The description of the target material in this project will contribute to the evolutionary and taxonomic knowledge of Chelidae, as well as to a better understanding of the Oligocene paleoenvironment in São Paulo.