Morphological diagnoses of higher taxa in Ophiuroidea (Echinodermata) in support of a new classification Author Stöhr, Sabine Author Hugall, Andrew F. Author Thuy, Ben Author Martynov, Alexander text European Journal of Taxonomy 2018 2018-03-21 416 1 35 journal article 22339 10.5852/ejt.2018.416 2eebb037-4ab1-433c-a9f6-8fe319e9fda9 3806109 AD094812-5768-43E9-BCC2-9226E69F0820 Order Ophioleucida O’Hara et al. , 2017 Diagnosis Dorsal disc with granules. Radial shields with distal adradial portion exposed. Abradial genital plate with concave adradio-distal tip. Dorsal arm plates rectangular to trapezoid with straight edges. Arm spine articulations irregularly rhombic, framing large, dorsoventrally elongated muscle opening, small nerve opening ventral to articulation. Lateral arm plates fragile. Arm spine articulations commonly separated from distal plate edge by a ledge. Ventro-distal edge of lateral arm plates protruding ventralwards.