Washakius insignis Leidy, 1873

Kelly, Thomas S. & Murphey, Paul C., 2016, Mammals from the earliest Uintan (middle Eocene) Turtle Bluff Member, Bridger Formation, southwestern Wyoming, USA, Part 1: Primates and Rodentia, Palaeontologia Electronica 7 (8), pp. 1-55 : 11

Washakius insignis Leidy, 1873

Figure 4.6 , Table 1

Referred Specimen. From UCM Locality 92189: M1 or 2, UCM 68541.

Description. UCM 68541 exhibits the following characters: 1) moderate size; 2) a large protocone; 3) a distinct hypocone; 4) a robust protoconule; 5) a two-cusped metaconule (doubled), with the larger of the two cusps positioned near the lingual base of the metacone; 6) paracone and metacone apices nearly in line with a relatively straight centrocrista extending between them; 7) a small mesostyle; and 8) strong labial, anterior, and posterior cingula.

Remarks. Based on a single, isolated tooth, the position of UCM 68541 cannot be unequivocally determined. It is lacking a pericone, a character that Tornow (2005) found to be variable on the M1- 2 of Washakius insignis . In his study, a pericone was lacking on 43% of the M1s and 10% of the M2s. In size, UCM 68541 is within the observed ranges of both the M1 and M2 of W. insignis ( Tornow, 2005) . In all other occlusal characters, UCM 68541 agrees well with the M1-2 of W. insignis ( Gazin, 1958; Szalay, 1976; Tornow, 2005; Gunnell et al., 2008) and is referred to the species.

Figures

FIGURE 4. Primates from TBM. 1-3, Notharctus robustior: 1, RM1, DMNH 75300; partial RM1 or 2, UCM 78457; 3, partial RM3, UCM 69054. 4-5, Trogolemur myodes: 4, Rm2, UCM 78097; 5, Rm3, UCM 67883. 6, Washakius insignis, LM1 or 2, UCM 68541. 7-9, Omomys carteri: 7, LM3, 110357; 8, Lm1, SDSNH 110355; 9, Rm3, DMNH 75326. All occlusal views. Scale bar equals 1 mm.