Protypotherium claudum Ameghino, 1889

(Fig. 8B–D; Supporting Information, Table S2)

1889 Protypotherium claudum Ameghino, p. 480 (original description), pl. 14, fig. 22.

Holotype: MACN-A 551 (Fig. 8B), right mandibular fragment with p2 (alveolus)–p3–m2 (see Fernández et al. 2018), Early– Middle Miocene, SCF, Santa Cruz Province (Argentina).

Referred materials: MLP 73-VII-6-4 d (ex Interatheriinae indet; Fig. 8C), less mandibular fragment with p2 (broken)–m2 (trigonid), and MPEF-PV 1394 (Fig. 8D), incomplete mandible with less i1–dp1–p2–4, and right i1 and dp1–p2–m3.

Extended diagnosis: Protypotherium claudum differs from Pr. compressidens, Pr. antiquum, Pr. australe, Pr. praerutilum, Pr. columnifer, Pr. minutum, and Pr. colloncurensis by p2–3 without the entoflexid and with the ectoflexid wider and slightly more mesially placed, and p4–m3 with shallower entoflexid; from Pr. australe and Pr. distinctum by having a smaller size; from Pr. compressidens by having relatively wider lower cheek teeth; from Pr. antiquum by the talonid of m3 without labial groove; from Pr. colloncurensis and Pr. columnifer by the talonid of p2–4 sub-triangular in outline; and from Pr. columnifer by the talonid of p4 narrower than the trigonid.

Geographic and stratigraphic provenance: Santa Cruz Province (Argentina), SCF, Early–Middle Miocene, Santacrucian SALMA; Río Negro Province (Argentina), Collón Curá Fm., Middle Miocene, Colloncuran SALMA.

Measurements: Supporting Information, Table S2.