Dataset 3D models related to the publication: Old fossil findings in the Upper Triassic rocks of southern Brazil improve diversity of traversodontid cynodonts (Therapsida, Cynodontia) Maur´ ıcio Rodrigo Schmitt 1 *, Agust´ ın Martinelli 2 , Jo ˜ ao Felipe Leal Kaiuca 3 , Cesar Leandro Schultz 4 , Marina Bento Soares 5 1 Programa de P ´ os-Graduac ¸˜ ao em Geoci ˆ encias, Instituto de Geoci ˆ encias, Universidade Federal do Rio Grande do Sul, Av. Bento Gonc ¸ alves, 9500, 91501-970, Bairro Agronomia, Porto Alegre, Rio Grande do Sul, Brazil 2 Secci ´ on Paleontolog´ ıa de Vertebrados, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”-CONICET. Av. ´ Angel Gallardo 470, C1405DJR, CABA, Buenos Aires, Argentina 3 Programa de P´ os-Graduac ¸˜ ao em Biodiversidade e Biologia Evolutiva, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Instituto de Biologia, Interbloco B/C, CCS, Rio de Janeiro, RJ, Brazil 4 Departamento de Paleontologia e Estratigrafia, Instituto de Geoci ˆ encias, Universidade Federal do Rio Grande do Sul, Av. Bento Gonc ¸alves 9500, 91501-970, Bairro Agronomia, Porto Alegre, Rio Grande do Sul, Brazil 5 Departamento de Geologia e Paleontologia, Museu Nacional, Universidade Federal do Rio de Janeiro, Quinta da Boa Vista s/n, S˜ ao Cristov ˜ ao, 20940-040 Rio de Janeiro, RJ, Brazil *Corresponding author: mauricio.schmitt@yahoo.com.br Abstract The present 3D Dataset contains the 3D models of a skull and lower jaw of the holotype of Santagnathus mariensis, described in “Old fossil findings in the Upper Triassic rocks of southern Brazil improve diversity of traversodontid cynodonts (Therapsida, Cynodontia)” Keywords: Gomphodontosuchinae, Hyperodapedon Assemblage Zone, Late Triassic, Traversodontidae Submitted:01/06/2023, published online:09/06/2023. https://doi.org/10.18563/journal.m3.198 M3 number Description M3#1157 Skull M3#1158 Lower jaw Table 1. List of models of Santagnathus mariensis. Specimen: UFRGS-PV-1419-T. Collection: UFRGS, Porto Alegre, Brazil. INTRODUCTION Traversodontidae is a large group of cynodont therapsids and the most diverse clade within Gomphodontia. It is well rep- resented in the Triassic fossil record of South America (e.g., Abdala and Ribeiro, 2010; Abdala et al., 2020; Schultz et al., 2020). We describe a new species of Traversodontidae cynodont in the Brazilian Triassic, with close affinities to Exaeretodon riograndensis and Siriusgnathus niemeyerorum. We scanned the skull and lower jaw of the holotype (UFRGS-PV-1419-T) and digitally processed the 3D model of the specimen (Fig. 1, 1 and table 1) to wide distribution of the data. This publication accompanies “Old fossil findings in the Upper Triassic rocks of southern Brazil improve diversity of traversodontid cynodonts (Therapsida, Cynodontia)” (Schmitt et al. 2023). METHODS The holotype (UFRGS-PV-1419-T) was scanned with a medical CT scanner (GE Brigthspeed 16 channels) at Serpal Clinica de Diagn ´ ostico, in Porto Alegre, Brazil. The 3D surfaces were extracted manually with segmentation software. The 3D surface models are provided in .ply format, and can therefore be opened with a wide range of freeware. ACKNOWLEDGEMENTS We thank the curator of the Universidade Federal do Rio Grande do Sul (UFRGS), Heitor Roberto Dias Francischini for the ac- cess to the specimens and to Pedro Henrique Morais Fonseca for the assistance with the CT data processing. Project funded by: CAPES, Grant number: PROEX 88882.345539/2019-01; Grant sponsor: CNPq, Grant numbers: 311251/2021-8; 307938/2019- 0; Grant sponsor: FAPERJ, Grant numbers: E-26/010/002540 /2019; E-26/201.066/2021; Grant sponsor: PalSIRP, Grant num- ber: 2016/2017 and 2018; Grant sponsor: Ginko Foundation; Grant sponsor: PICT, Grant number: 2020-SERIEA-01498. BIBLIOGRAPHY Abdala, F., Ribeiro, A. M. 2010. Distribution and diversity pat- terns of Triassic cynodonts (Therapsida, Cynodontia) in Gond- wana. Palaeogeography, Palaeoclimatology, Palaeoecology 286 (2010) 202–217. https://doi.org/10.1016/j.palaeo.2010.01.011 Abdala, F., Gaetano, L. C., Martinelli, A. G., Soares, M. B., Hancox, P. J., Rubidge, B. S. 2020. Non-mammaliaform cyn- odonts from western Gondwana and the significance of Argen- tinean forms in enhancing understanding of the group. Jour- nal of South American Earth Sciences 104 (2020) 102884. https://doi.org/10.1016/j.jsames.2020.102884 Schmitt, M. R., Martinelli, A. G., Kaiuca, J. F. L., Schultz, C. L., Soares, M. B. 2023. Old fossil findings in the Upper Triassic rocks of southern Brazil improve diversity of traversodontid cynodonts (Therapsida, Cynodontia). The Anatomical Record,