Ophiactidae Matsumoto, 1915

Stöhr, Sabine, Hugall, Andrew F., Thuy, Ben & Martynov, Alexander, 2018, Morphological diagnoses of higher taxa in Ophiuroidea (Echinodermata) in support of a new classification, European Journal of Taxonomy 416, pp. 1-35 : 21-22

Family Ophiactidae Matsumoto, 1915

Type genus

Ophiactis Lütken, 1856 (type species: O. krebsii Lütken, 1856 = O. savignyi ( Müller & Troschel, 1842)) .

Other genera

Hemipholis Lyman, 1865 .

Diagnosis

Dorsal disc with scales and plates, often with conical spines. Large tricuspid teeth. Dorsalmost tooth socket large fenestration with incomplete septum, other dorsal sockets with complete septum, ventral sockets not penetrating depressions. Infradental papillae in lateral position at dental plate. Arm spine articulation with two separated lobes, dorsal one bent and much larger than ventral one, framing two holes for muscle and nerve, separated by thin bridge. Lateral arm plates commonly with outer surface tubercles. Inner side of lateral arm plates with separate knobs sometimes associated with ridge.

Remarks

Ophiactis forms two clades based on number of lateral oral papillae (two or one), which are paraphyletic with respect to each other on some molecular topologies ( O’Hara et al. 2017).