[Papers in Palaeontology, 2017, pp. 1–23] A NEW CYNODONT FROM THE SANTA MARIA FORMATION, SOUTH BRAZIL, IMPROVES LATE TRIASSIC PROBAINOGNATHIAN DIVERSITY by AGUSTIN G. MARTINELLI1 , ESTEVAN ELTINK2, ATILAA.S.DA-ROSA 3 and MAX C. LANGER4 1Laboratorio de Paleontologia de Vertebrados, Departamento de Paleontologia e Estratigrafia, Instituto de Geoci^encias, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Goncßalves 9500, Agronomia, 91540–000, Porto Alegre, RS Brazil;
[email protected] 2Colegiado de Ecologia, Universidade Federal do Vale do S~ao Francisco, Av. Tomaz Guimar~aes S/N, Bairro Santos Dumont, 48970000, Senhor do Bonfim, BA Brazil;
[email protected] 3Laboratorio de Estratigrafia e Paleobiologia, Departamento de Geoci^encias, Universidade Federal de Santa Maria, Av. Roraima, 1000, predio 17, sala 1131B, 97105-900, Santa Maria, RS Brazil;
[email protected] 4Laboratorio de Paleontologia de Ribeir~ao Preto, FFCLRP, Universidade de S~ao Paulo, Av. Bandeirantes 3900, 14040-901, Ribeir~ao Preto, S~ao Paulo Brazil;
[email protected] Typescript received 30 January 2017; accepted in revised form 10 April 2017 Abstract: The fossil record of non-mammaliaform based on a left lower jaw with almost complete dentition probainognathian cynodonts is outstanding in the Late Tri- that exhibits a combination of features not seen in any other assic rocks of Brazil and Argentina. Approximately 15 genera known probainognathian. Its slender lower jaw, anterodor- are known, providing unique insights in the study of the sally bent process of the dentary, high number of lower inci- major skeletal transformations prior to the mammalian con- sors, reduced canine, triconodont-like postcanine teeth with dition.