Description--Skull large (GLS: 31.2 mm) and robust; rostrum long (LNR: 9.5 mm), robust and heavy; postorbital region very constricted (INC: 8.1 mm); sagittal crest
poorly developed; lambdoidal crest well developed; mastoidal processes broad (MAB: 15.7 mm); incisors 1/2, upper incisors in contact at the bases and divergent at the apices, with a well developed internal cingulum; apical margin of the lower incisors bilobed, i2 covered by the cingulum of the canines in occlusal view; canines with external cingulum very developed; premolars 2/2, P3 very small, located at the base of the canine; molars dilambdodont, M3 half the size of the formers, ectoloph in occlusal view form an incomplete "W"; talonid of M3 and m3 reduced.
In carnivores and omnivores, there is a ridge on top of the skull called a sagittal crest
. The site of muscle attachment for the strong muscle that controls the crushing lower jaw, the sagittal crest
is quite pronounced on opossum and fisher, and less pronounced on coyote, raccoon and otter.