Riograndia [SEP] parent taxon
classified as a basal genus in the family Tritheledontidae. Other tritheledontids include the related "Irajatherium", and two clades, a more basal group including "Sinoconodon", "Brasilitherium", "Brasilodon", and "Morganucodon", and a more derived clade of "Chaliminia", "Elliotherium", "Pachygenelus", "Diarthrognathus", and "Tritheledon". The below cladogram was found by Martinelli and Rougier in 2007 and modified by Soares "et al." in 2011, with Tritheledontidae added after Ruta
Riograndia
Riograndia is an extinct genus of tritheledontid cynodonts from the Late Triassic of South America. The type and only species is Riograndia guaibensis. Remains have been found in the Caturrita Formation of the geopark of Paleorrota. It was a small non-mammalian cynodont several advanced features also present in mammals. Several specimens of "Riograndia guaibensis" have been found in the towns of Candelária and Faxinal do Soturno in the Caturrita Formation. The genus defines the "Riograndia" Assemblage Zone.
Classification.
"Riograndia" is currently