The Echinoid Directory

Contributed by Andrew Smith, August 2011

Isopetalum Lambert, 1911, p. 188

[= Homoianthoides Lambert, 1920, p. 193 (27) (objective). ]

Diagnostic Features
  • Small, subglobular form with shallow anterior sulcus
  • Apical disc plating unknown
  • Ambulacrum III in shallow sulcus. Paired ambulacra strongly petalloid; the anterior pair very much longer than the posterior pair.
  • Peripetalous fasciole present; lateroanal fasciole not reported.
Distribution Oligocene, Italy
Name gender neuter
Type Linthia pseudoverticale Oppenheim, 1901, p. 107, by original designation
Species Included Only the type species
Classification and/or Status Spatangoida, ?Schizasteridae

Incertae sedis
Remarks This species is supposed to have petaloid pore-pairs in the anterior ambulacrum but that is based on a very poor drawing and seems highly unlikely.  The genus is treated as incertae sedis until the type material is re-examined critically.

Lambert, J. 1911. Notes sur quelques echinides eoceniques des Corbieres septentrionales. Annales de la Universite du Lyon nouvelle serie 1, Sciences, Medicines 30, 165-199.