|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Ophiuroidea - Oegophiurida - Protasteridae
If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.
|R. V. Kesling and D. Le Vasseur 1971||Protasterid brittle-stars with disk covered by integument bearing internal thin irregular mosaic plates and external papillae. Oral surface of disk and aboral surfaces of arm papillose. Mouth frame large and set upon appreciable incline Ambb2. Tori bearing a few large but delicate denticules. Ambb "boots" with a thin shallow groove across the "leg" and a longitudinal groove from the "ankle" to the "instep". Ambb trapezoidal in aboral outline; the two subterminal ridges convergent away from the aboral mid-line, but separated by a deep channel, leaving space for dorsal musculature. Junction between alternating ambb in two halves of arm slightly sinuous. LL not overlapping, each provided with several oral spines and a few distal spines; L "nose" ridge-like, its articulation with amb nearly straight and half as long as the plate. Cupules for tube feet well defined and fairly deep. arms tapering evenly to terete tip; in distal section of arm, LL usually contracted orally to effectively obscure ambulacrum. M small and inconspicuous crossed by a slot.|
|F. H. C. Hotchkiss 1993||Frotasterid brittlestars with upper arm plates and carinal spines; upper arm plates are not in register with the ambulacrals, and their series end before the arm tip. Uppermost vertical spines project at a high angle from the sides of the arms. Aboral outline of proximal ambulacrals trapezoidal, accommodating large dorsal longitudinal muscles. Disc radius up to 8 mm; arm length five to six times disc radius. Where arms become free of disc, their width (not including splayed vertical spines) equals about half the disc radius.|