The Echinoid Directory

Contributed by Andrew Smith, July 2008

Eodiadema Duncan, in Wilson & Crick 1889, p. 339

Diagnostic Features
  • Test small, with domed upper surface
  • Apical disc  hemicyclic, with posterior two ocular plates contacting periproct.
  • Ambulacra straight, with trigeminate plating throughout.  Plate compounding acrosaleniid style, with primary tubercle overlapping two elements in each triad.  All three elements identical in shape and reaching perradius.
  • Interambulacra with single primary tubercle that is perforate and crenulate. Interradial zone broad and granular adapically. Primary tubercles distinctly smaller on adapical surface.
  • Peristome relatively large, slightly sunken and with rather open, U-shaped buccal notches.
  • Spines and lantern unknown.
Distribution Lower Jurassic (Pliensbachian), England
Name gender neuter
Type Eodiadema granulatum Wilson, in Wilson & Crick, 1889. lectotyps: BMNH E76506 by subsequent designation of Smith 2016, p. 71.
Classification and/or Status Subjective junior synonym of Glyptodiadema Pomel, 1883
Remarks Duncan, 1889. A revision of the genera and great groups of the Echinoidea. Zoological Journal of the Linnean Society, 23, 1-331.

Smith, A. B. 2016. British Cretaceous regular echinoids. Part 2 Carinacea. Monographs of the Palaeontographical Society (no. 646), pp. 69-176, pls 42-82.

Wilson, E. in Wilson, E. & Crick, W. D. 1889. The Lias Marlstone of Tilton, Leicestershire. Geological Magazine 6 (dec. 3): 337-342, pl. 10.