 Mochizuki and Ohe originally assigned the viper dogfish to the family <unk> , which at the time was used for all members of the order Squaliformes aside from the bramble and rough sharks . In a 1992 morphological study , Shigeru Shirai and Osamu Okamura placed this species in the squalid subfamily <unk> , which most taxonomists now recognize as the separate family Etmopteridae . 
