The Echinoid Directory

Allotoxaster Nisiyama, 1968, p. 181

Diagnostic Features
  • Test small, oval in outline with rounded margin; steeply rounded anterior and truncate posterior. Feeble frontal depression at ambitus. Oral surface weakly convex.
  • Apical disc central; structure unknown but clearly compact.
  • Ambulacrum all similar; subpetaloid; flush adapically; open distally. Petaloid zones open and ending gradually; weakly flexed.
  • Peristome small, subcircular; facing obliquely towards shallow anterior furrow.
  • Plastron plating unreported.
  • Periproct small and towards the top of posterior truncate face.
  • Tubercles and spines unknown.
Distribution Japan. Originally listed as Cretaceous, but stated to be Upper Jurassic by Nisiyama (1968) - Jurassic age seems highly implausible.
Name gender masculine
Toxaster tosaensis de Loriol, 1902, p. 36, by original designation.
Species Included Only the type species.
Classification and/or Status
Spatangoid indet.

Monotypic; indeterminate.


The type is based on a specimen that has lost the external surface of the test.

de Loriol, P. 1902. Notes pour servir a l'etude des Echinodermes. Seconde Serie, fascicule 1. Bale & Geneve, Librairie Georg & Co.

Nisiyama, S. 1968. The echinoid fauna from Japan and adjacent regions part II. Palaeontological Society of Japan Special Papers 13, 1-491, pls 1-30.