Family Ophiobyrsidae Matsumoto, 1915 stat. nov. (raised to family-rank)
Type genus
Ophiobyrsa Lyman, 1878a (type species: O. rudis Lyman, 1878a).
Other genera
Ophiobyrsella Verrill, 1899b, Ophiosmilax Matsumoto, 1915, Ophiophrixus H.L. Clark, 1911 .
Diagnosis
Disc and arms covered by thickened skin bearing pointed spines, large radial shields. Vertebrae with hourglass-shaped articulation. Multiple columns of spiniform teeth on round, knob-like sockets, not perforating the dental plate. Ventral tooth cluster. Spine articulation asymmetrical with large, swollen dorsal lobe and small,indistinct ventral lobe. No sigmoidal fold. Lateral arm plates without ornamentation.
Remarks
New molecular data indicates that the genera Ophiobyrsa, Ophiophrixus and Ophiosmilax form a clade that is sister to all remaining ophiacanthid families. Consequently, the former subfamily Ophiobyrsinae Matsumoto, 1915 is raised to family-level rank.