Bessoecetor septentrionalis Scott et al., 2002

Lofgren, Donald, Mckenna, Malcolm, Honey, James, Nydam, Randall, Wheaton, Christine, Yokote, Bryan, Henn, Lexington, Hanlon, Whitney, Manning, Stephen & Mcgee, Carter, 2014, New records of eutherian mammals from the Goler Formation (Tiffanian, Paleocene) of California and their biostratigraphic and paleobiogeographic implications, American Museum Novitates 2014 (3797), pp. 1-60 : 5-6

Bessoecetor septentrionalis Scott et al., 2002

HOLOTYPE: AMNH 33810 , left dentary with p2–m3 from Scarritt Quarry, Fort Union Formation , Montana.

REFERRED SPECIMEN: RAM 9099, right dentary fragment with m2–m3 from RAM locality V200510, member 4a ( fig. 2A–B ).

DESCRIPTION AND DISCUSSION: ” Propalaeosinopa ” was the generic name employed for a common North American Torrejonian–Tiffanian pantolestid, but Scott et al. (2002) demonstrated that the type of “ Propalaeosinopa ,” P. albertensis , is a nomen dubium. Van Valen (1967) originally proposed the synonymy of Bessoecetor thomsoni , B. diliculi , and “ Propaleosinopa ” albertensis . Scott et al. (2002) argued that B. diliculi is identical to the type of “ Diacodon ” septentrionalis described by Russell (1929), and thus has priority. Scott et al. (2002) then resurrected Bessoecetor and transferred the four species of “ Propaleosinopa ” ( P. thomsoni , P. dilucli , P. albertensis , P. septentrionalis ) to the new combination, Bessoecetor septentrionalis . This synonymy was provisionally followed by Secord (2008), but he noted that the type specimen of the genus should be the holotype of B. thomsoni (AMNH 33810) from Scarritt Quarry, not the type of “ Diacodon ” septentrionalis (UALVP 126).

The m2–m3 of RAM 9099 have tall trigonids with large protoconids and metaconids and small paraconids that are shifted labially and low talonids with large hypoconids and slightly smaller entoconids, with small and medially placed hypoconulids ( fig. 2A–B ); features present in both known species of Bessoecetor , B. septentrionalis and B. pilodontus . However, B. septentrionalis can be differentiated from B. pilodontus by size, although teeth of B. pilodontus and B. septentrionalis may overlap slightly in length ( Secord, 2008). Tooth dimensions of RAM 9099 are very similar to the holotype of B. septentrionalis and are significantly smaller than the holotype of B. pilodontus ( table 1). Therefore, RAM 9099 is referred to B. septentrionalis .

Order CARNIVORA Bowdich, 1821

Family VIVERRAVIDAE Wortman and Matthew, 1899

Figures

FIGURE 2. Mandibles and teeth of Protictis, Bessoecetor, and Taeniodonta. A. Occlusal view of RAM 9099, right dentary fragment with m2–3 of Bessoecetor septentrionalis from RAM locality V200510; B. labial view of RAM 9099. C. Lingual view of RAM 6927, a right dentary fragment with c, p1–p2, p4, and partial m1 of Protictis paralus from RAM locality V200001 (with partial imprint of dentary); D. occlusal view of p1–2, p4–m1 of RAM 6927. E. Lingual view of partial m1 of RAM 7246, left dentary fragment with partial m1 of Protictis cf. P. agastor from RAM locality V200001; F. labial view of partial m1 of RAM 7246; G. occlusal view of RAM 7246. H. Posterior view of RAM 15328, partial lower canine of a taeniodont from RAM locality V200612; I. anterior view of RAM 15328. Scale bar for C–D also applies to E–G.