The Echinoid Directory

Contributed by Andreas Kroh, March 2011

Skouraster Lambert, 1937, p. 89

Diagnostic Features	Test ovate with shallow anterior sulcus. Apical disc situated posterior of centre, structure unknown Anterior ambulacrum narrow and shallowly sunken throughout; pore-pair structure unknown. Paired ambulacra petaloid, petals sunken and straight-sided; closed distally. Anterior pair forming an angle of around 130 degrees. Posterior petals about half as long as anterior ones. Adapical pores rudimentary. Coronal plating pattern unknown. Peristome subpentagonal, strongly displaced anteriorly. Periproct high on posterior truncate face; small. Broad peripetalous fascioles present.
Distribution	Eocene, North Africa.
Name gender	masculine
Type	Palaeostoma zitteli de Loriol , 1881, p. 33, by original designation
Species Included	Palaeostoma zitteli de Loriol, 1881; Eocene, Egypt. Paleostoma [sic!] rochi Lambert, 1937; Eocene, Morocco.
Classification and/or Status	Spatangoida.
Remarks	Distinguished from Palaeostoma by the presence of a frontal notch. Very similar to juveniles of some species of Ditremaster. Type species poorly known and in need of redescription; placement uncertain as based on juveniles. Lambert, J. 1937. Echinides fossiles du Moroc. Protectorat de la Republique Francaise au Maroc, Service des Mines et de la Carte Geologique, Notes et Memoires 39, 39-109. de Loriol, P. 1883. Eocane Echinoideen aus Aegypten und der libyschen Wuste. Palaeontographica 30(2), 1-60. Roman, J. & Strougo, A. 1994. Echinoides du Libyen (Eocene inferieur) d'Egypte. Revue de Paleobiologie 13, 29-57.