The Echinoid Directory

Echanthus Cooke, 1942, p. 37

Diagnostic Features
  • Test of medium size, subpentagonal in outline with a short, truncated posterior margin; greatest width posterior of centre. Upper surface moderately inflated, highest point slightly behind the apical disc, flat oral surface, slightly sunken towards the peristome.
  • Apical system monobasal, with four genital pores; anterior of centre.
  • Petals well developed, narrow, open distally, extending more than halfway to margin; poriferous zones of equal length in the same petal. Pores circular, conjugate; ambulacral plates beyond petals with single pores.
  • Peristome anterior, subpentagonal, wider than long; vertical walled entrance to peristome.
  • Periproct marginal, longitudinal.
  • Bourrelets developed as low mounds around peristomial opening.
  • Phyllodes broad, single pored, with two series of pores in each half-ambulacrum.
  • Buccal pores present.
  • Tubercles larger on adoral surface than adapically, narrow granular sternal zone in interambulacrum 5.
Distribution
  • Palaeocene USA.
Name gender masculine
Type
Echanthus georgiensis Twitchell, 1915, p. 139; by original designation.
Species Included
  • Only the type species.
Classification and/or Status

Irregularia; Cassiduloida; 'Gitolampadids'

Subjective junior synonym of Gitolampas Gauthier, 1889.

Remarks

The type species of Echanthus and Gitolampas are very similar and are most likely congeneric (Kier, 1962, p. 210). Both have a similar shape, with the greatest width posterior to the centre, a pointed posterior extremity, broad petals, and a similar floscelle.

Cooke (1942, p. 211) erected this genus for Echinanthus Desor (1858) non Leske (1778), because he believed Desor's Echinanthus to be preoccupied.

C. W. Cooke. 1959. Cenozoic echinoids of eastern United States. United States Geological Survey, Professional Paper, 321, 106 pp., 43 pls.

P. M. Kier. 1962. Revision of the cassiduloid echinoids. Smithsonian Miscellaneous Collections 144, (3), 262 pp.