There are two specimens labelled as types: MACN A 297 is a palate with both molar series, which corresponds with the palate described and illustrated by Ameghino (1889, pl. 13, fig. 25); MACN 262 is a left mandibular fragment with p2–m2 that does not correspond with the original description. The author figured a left mandibular ramus with p3–m3 (Ameghino 1889, pl. 13, fig. 27) and another fragment with right and left i1 and left i2–p3 (Ameghino 1889, pl. 13, fig. 26). We interpret that he combined these two fragments to obtain the length pro- vided for the six lower teeth (p2–m3) (Ameghino 1889, p. 429), but none of these figures coincides with MACN 262, and therefore we remove this specimen from the type material of P. teres. In contrast, among other remains assigned to P. teres, the left mandibular ramus MACN A 3308 and the symphysis and partial left ramus MACN A 277 match the mentioned illustra- tions (Ameghino 1889, pl. 13, figs 26, 27); therefore, MACN A 3308, MACN A 277 and the palate MACN A 297 constitute the syntypes of P. teres. Other specimens assigned to this species are detailed in Supplementary material,