The Echinoid Directory

Cyrtechinus Mortensen, 1942, p. 229

Diagnostic Features
  • Apical disc hemicyclic, usually with oculars I and V insert. Anal opening central.
  • Ambulacral plating trigeminate. Pore-pairs arranged in arcs forming a single band.
  • Interambulacral plates with central primary tubercle and slightly smaller secondary tubercles on either side. Ambulacra with one or two subequal tubercles per plate.
  • Peristomial membrane densely covered in plates.
Recent; Indo-West Pacific littoral to 130 m.
Name gender masculine
Psammechinus verruculatus Lutken, 1864, p. 98, by original designation.
Species Included
Only the type
Classification and/or Status

Camarodonta; Echinoida; Toxopneustidae.

Monotypic. Here treated as a junior subjective synonym of Nudechinus Clark, 1912.


Distinguished from Lytechinus primarily on the larval stage morphology, In Cyrtechinus the larva lacks a basket structure, whereas this is always developed in Lytechinus. The primary test character differentiating the two is that Cyrtechinus is densely covered in tubercles throughout, whereas in Lytechinus there are adapical interradial naked zones. It differs from Nudechinus only in having a densely plated peristomial membrane. In other respects it is virtually indistinguishable, and Mortensen noted the close similarity of the two genera when erecting this taxon.

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