The Echinoid Directory

Scoliechinus Arnold & Clark, 1927, p. 23

Diagnostic Features	Test small (25 mm); domal in profile Apical disc plating lost; small (less than 20% test diameter); presumed hemicyclic or dicyclic Ambulacral plating trigeminate, with pore-pairs in arcs of three forming a single broad band; more or less of uniform width throughout. Plate compounding echinoid, with one occluded element and with the primary tubercle binding the other two elements. Ambulacral plates with two primary tubercles at ambitus (one aborally) and narrow naked perradial zone adapically Interambulacra with up to four equal-sized plates subambitally and with a prominent naked interradial zone adapically. All tubercles imperforate and non-crenulate Deep buccal notches extending to third or fourth interambulacral plate Peristome large; 50% test diameter Spines and lantern unknown
Distribution	Middle Eocene, Yellow Limestone Group of Jamaica
Name gender	masculine
Type	Scoliechinus axiologus Arnold & Clark, 1927, by original designation. Holotype: Museum of Comparative Zoology, Harvard 101824.
Species Included	Only the type
Classification and/or Status	Camarodonta; Echinoida; Toxopneustidae A junior subjective synonym of Lytechinus A Agassiz, 1863.
Remarks	This taxon is rather poorly known. It was originally thought to be Cretaceous, but is now almost certainly Middle to late Eocene in age (Donovan & Lewis 1993). It has trigeminate ambulacra with pore-pairs arranged in subvertical arcs and obvious naked interradial and perradial zones adapically. Like Lytechinus it also has multiple subequal tubercles on ambital and subambital plates. No significant characters distinguish it from Lytechinus. Donovan, S. K. 1992. Jamaican Cretaceous Echinoidea (Echinodermata). 3. Scoliechinus axiologus Arnold & Clark, 1927, and an indeterminate cassiduloid. Proceedings of the Biological Society of Washington 105, 23-31. Donovan, S. K. & Lewis, D. N. 1993 Caribbean Journal of Science 29, 188-189.