Boreogomphodon jeffersoni was named in 1990. Its teeth and cranial bones are the most common tetrapod fossils in the Turkey Branch Formation. Remain assigned to
B. jeffersoni are also known from the Pekin Formation of North Carolina.
Boreogomphodon was distinguished from other traversodontids like the African
Luangwa and the South American
Traversodon on the basis of its postcanine teeth. Most traversodontids have lower postcanine teeth with two cusps, but
Boreogomphodon was the first traversodontid found with three cusps on its lower postcanine teeth. There is a single cusp on the side of the upper postcanine facing the lip, while a flat surface extends outward from it. The traversodontid
Arctotraversodon from the
Wolfville Formation of
Nova Scotia is similar to
Boreogomphodon in that it has three cusps on its lower postcanine, but its postcanines are much wider than they are long relative to those of
Boreogomphodon.
Boreogomphodon specimens likely represent juvenile individuals because of their small size. The snout is short, while larger, presumably mature traversodonts have longer snouts.
Boreogomphodon specimens have only four or five postcanine teeth. Traversodontids acquire more of these teeth as they grow, suggesting that
Boreogomphodon individuals were not fully mature.
Boreogomphodon also has some sectorial, or cutting, postcanine teeth, which are not present in most larger traversodontids. ==Classification==