The Echinoid Directory

Contributed by Andrew Smith, August 2011

Pseudowashitaster Tanaka, in Takana & Kozai, 1982, p. 346

Diagnostic Features	Test large, ovate with anterior groove Apical disc very far towards the posterior; ethmophract with 4 gonopores. Ambulacrum III in sulcus aborally; wide, with uniform, uniserially arranged pore-pairs; the two pores elongate, especially the outer, and slightly variable in width Paired petals flush and strongly flexed. The anterior petals have only rudimentary pores in the anterior column and are more than 3 times as long as the posterior petals. Posterior petals strongly divergent Oral plating unknown Peripetalous fasciole (?parafasciole) present
Distribution	Lower Cretaceous (Barremian), Japan
Name gender	masculine
Type	Pseudowashitaster mysticus Takana, in Takana & Kozai, 1982, p. 348
Species Included	Only the type species
Classification and/or Status	Spatangoida, Toxasteridae Monotypic
Remarks	In overall morphology this is very close in appearance to Heteraster but differs in having a well defined peripetalous fasciole and less heterogeneous pore-pairs in its anterior ambulacrum. While toxasterids in general lack fascioles, partially developed bands occur in Washitaster and this taxon is better considered as a toxasterid that has independently evolved a peripetalous fasciole than as a hemiasterid convergent on Heteraster. Takana, K. & Kozai, T. 1982. Some Cretaceous echinoids from the Monobe area, central Shikoku. Transactions and Proceedings of the Palaeontological Society of Japan 126, 341-355.