The Echinoid Directory

Sphaerechinus Desor, 1856, p. 134

[=Trichoelina Barrois, 1887; = Spherechinus Lambert, 1928]

Diagnostic Features
  • Test large and hemispherical with rounded base, sunken towards peristome.
  • Apical disc hemicyclic.
  • Ambulacral plating polygeminate with 4 to 6 pore-pairs to a plate; pore-zones narrow.
  • Pore-pairs arranged as an arc on each plate; one primary tubercle on each plate.
  • Multiple equal-sized tubercles on interambulacral plates forming horizontal series at the ambitus. No aboral naked zones.
  • Buccal notches sharp and pronounced.
  • Auricles joined perradially.
Distribution
Pliocene to Recent; Atlantic and Mediterranean.
Name gender masculine
Type
Echinus granularis Lamarck, 1816, by original designation.
Species Included
  • S. granularis (Lamarck, 1816); Pliocene - Recent, Mediterranean.
Classification and/or Status

Camarodonta; Echinoida; Toxopneustidae.

Monotypic.

Remarks

The deep buccal notches and polyporous ambulacra distinguish this taxon from all but Pseudocentrotus and Pseudoboletia. Pseudocentrotus has a flat base, strongly developed phyllodes and more pore-pairs to an ambital plate and cannot be confused. Pseudoboletia is more simiar, but can be distinguished by having naked interradial and perradial zones adapically.

Mortensen, T. (1943) A monograph of the Echinoidea Part III.2, Camarodonta 1. C. A. Reitzel, Copenhagen