Species: rectangularis BONAPARTE, 2002
Etymology: In reference to the outline of the upper molar crown.
Holotype: MACN-RN 180
Locality: Estancia Los Alamitos, Arroyo Verde, Rio Negro Province, Argentina.
Horizon: Lower section of the Los Alamitos Formation.
Biostratigraphy:
Age: Alamitan Provincial Age, Allenian Tetrapoda Assemblage, Late Campanian-Early Maastrichtian Stage, Senonian Subepoch, Gulf Epoch, Late Cretaceous.
Material: A left molar with complete crown.