Species: borealis LEIDY, 1854
Etymology: Latin, borealis, "northern."
= Dimetrodon borealis (LEIDY, 1853) BRINK, MADDIN, EVANS, & REISZ, 2015
= Bathygnathus borealis LEIDY, 1853
Note: This combination is not valid, Bathygnathus has priority over Dimetrodon and you can not state that due to taxonomic stability, Dimetrodon has priority. This has to be petitioned to the ICZN, and have an ICZN ruling on the name priority. 

Holotype: ANSP 9524

Locality: Locality 3, 1 ¾ miles south of Cape Tryon Light, French River District (New London district), Prince Edwards Island red beds, Nova Scotia Province, Canada.

Horizon: Orby Head Formation (old Stephanian).

Biostratigraphy:

Age: Artinskian Stage, Cisuralian (old Rotliegendes) Epoch, Late Early Permian (old Silesian, upper Kasimovian to Gzelian Epoch, Latest Pennsylvanian Subperiod, Latest Carboniferous Period).

Material: Left side of face from just in front of the orbits to the external naris.