Cryptarcus ("Chasmosaurus") russelli holotype cranium (CMNFV 8800). (A) Skull in left lateral view (with restored jugal and lower jaw); (B) detail of snout in left lateral view; (C) detail of parietosquamosal frill in dorsal view; (D) detail of supraorbital review in dorsal view; (E) detail of es6 episquamosal; (F) detail of es7 episquamosal. Arrowheads in E and F point to margins of episquamosals.