The Echinoid Directory

Order Echinothurioida Claus, 1880


 Regular euechinoids with:

  • monocyclic apical disc in adults
  • lantern with grooved teeth
  • ambulacral plates continue onto the peristome forming regular series
  • ambulacral plates pseudocompound, with large primary element and two demiplates
  • coronal plates thin and with imbricate sutures
  • primary tubercles perforate
  • spines hollow.
Middle Jurassic (Bajocian) to Recent; worldwide.
Species Included Includes the families Kamptosomatidae, Echinothuriidae Pelanechinidae and Phormosomatidae
Echinothurioids have grooved teeth and a monocyclic apical disc like diadematoids but can be distinguished from that clade by having ambulacral plates continuing across the peristome membrane. Most have non-crenulate tubercles.

Claus, C. F. W. 1880. Grundzüge der Zoologie. 4th ed. N. G. Elwert´sche Universitätsbuchhandlung, Marburg & Leipzig, vol. 1: vii+821 pp., vol. 2: iv+522 pp.

Mortensen, T. 1935. A Monograph of the Echinoidea. II. Bothriocidaroida, Melonechinoida, Lepidocentroida, and Stirodonta. C. A. Reitzel, Copenhagen, 647 pp.