Siriusgnathus niemeyerorum (Eucynodontia: Gomphodontia): The youngest South American traversodontid?

• Published in: Journal of South American earth sciences Vol. 97; p. 102394
• Main Authors: Miron, Lívia Roese, Pavanatto, Ane Elise Branco, Pretto, Flávio Augusto, Müller, Rodrigo Temp, Dias-da-Silva, Sérgio, Kerber, Leonardo
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2020
• Subjects: Biostratigraphy; Candelária Sequence; Caturrita Formation; Gomphodontosuchinae; Norian; Triassic; Gomphodontosuchinae; Caturrita Formation; Triassic; Candelária Sequence; Norian; Biostratigraphy
• ISSN: 0895-9811; 1873-0647
• DOI: 10.1016/j.jsames.2019.102394

Traversodontidae is a less inclusive clade of cynognathian cynodonts that lived during the Triassic. Recently, a traversodontid from the southern Brazilian Triassic beds was described – Siriusgnathus niemeyerorum – based upon specimens found exclusively in its type-locality. No absolute age or index fossils have been reported for this locality, which prevents an accurate biostratigraphic correlation. In the present contribution, we describe the first specimens of S. niemeyerorum found outside its type-locality, comprising skull portions excavated from outcrops in southern Brazil assigned to the Caturrita Formation (upper portion of the Candelária Sequence), Upper Triassic (Norian), Riograndia Assemblage Zone. As a result, we provide an updated biostratigraphic framework and suggest a Norian age for the type-locality of S. niemeyerorum, which, accordingly, possibly comprises the youngest South American traversodontid, pending additional geochronological studies in order to properly evaluate this hypothesis. •New specimens of the traversodontid Siriusgnathus niemeyerorum are described.•They represent the first records of S. niemeyerorum outside its type-locality.•The studied sites are assigned to the Riograndia Assemblage Zone, Norian.•Siriusgnathusniemeyerorum may be the youngest known South American traversodontid so far.