An evaluation of dental features used to distinguish Typotheriopsis Cabrera and Kraglievich 1931, from Pseudotypotherium Ameghino 1904 (Mesotheriidae, Notoungulata): reappraisals and proposals about their systematic value

ARMELLA, MATÍAS A.; ERCOLI, MARCOS D.

AMEGHINIANA

ASOCIACION PALEONTOLOGICA ARGENTINA

Lugar: Buenos Aires; Año: 2018

0002-7014

The Mesotheriinae records in the late Neogene of Argentina are mostly grouped in two genera: Typotheriopsis and Pseudotypotherium. Both taxa were poorly diagnosed and/or based on juvenile specimens. Traditionally, the dental feature considered to distinguish them is the presence of a lingual groove in the last upper premolar. Other features were mostly dismissed or considered non-informative at a generic level. Based on this, we reanalyzed dental features in Typotheriopsis and Pseudotypotherium samples to evaluate their relevance in a taxonomic framework. This study brings new qualitative and quantitative tools to appraise diagnostic features present in fossil fragments and isolated dental mesotheriine pieces.