Diagnosis
provided by World Register of Marine Species
Hyocrinidae with basals fused or basal circlet with 1-3 sutures. Arms moderately narrow. Width of distal radial articular facet 74-81 percent of upper width of radial. Second nonmuscular articulation between brachials 5-6; synostoses occur regularly after brachial 7. Distal arm with fewer than 5 successive muscular articulations in juveniles and at most 22 in large adult specimens. First pinnule on brachial 4. Proximal part of genital pinnules with one row of lateral plates on each side, rarely joined by stereom bridges over gonad in H-shaped plates. Cover plates of distal pinnules with short, terminal, fingerlike projection; outer perpendicular spine or tubercle absent. Tegmen low to inflated. Oral plates of moderate size. Anal cone lower or higher than oral cone. Tegminal plates connected with brachials 1-4. Columnal symplexies with 6-10 crenular units of 1-3 crenulae each.
- license
- cc-by-4.0
- copyright
- WoRMS Editorial Board
- bibliographic citation
- Hess H. (2011). Hyocrinida. <em>In: Hess H, Messing CG, Ausich WI (Eds.), Treatise on Invertebrate Paleontology, Part T, Echinodermata 2 Revised, Crinoidea, vol. 3. University of Kansas Press, Lawrence, Kansas.</em> 172–179.
- contributor
- Messing, Charles, C.G.
