Mammalia - Theriiformes - Pantolestidae

Alternative combinations: Diacodon septentrionalis, Propalaeosinopa septentrionalis

Synonyms: Bessoecetor diluculi Simpson 1935, Bessoecetor thomsoni Simpson 1936, Palaeosinopa diluculi Simpson 1935, Propalaeosinopa diluculi Simpson 1935, Propalaeosinopa thomsoni Simpson 1936

Belongs to Bessoecetor according to C. S. Scott et al. 2002

Sister taxa: none

Type specimens:

• Bessoecetor septentrionalis: UALVP 126, a mandible (incomplete left dentary containing m3). Its type locality is Cochrane 1, which is in a Tiffanian terrestrial horizon in the Porcupine Hills Formation of Canada.
• Bessoecetor thomsoni:
• Palaeosinopa diluculi: Its type locality is Gidley Quarry, which is in a Torrejonian terrestrial horizon in the Fort Union Formation of Montana.

Average measurements (in mm): P4 2.45 x 2.15, M1 2.43 x 3.03, M2 2.60 x 3.70, p4 2.75 x 1.15, m1 2.39 x 1.71, m2 2.50 x 1.73