The Echinoid Directory

• Test of moderate size, oval in outline, pointed posterior extremity, low, greatest height adapically, with a flat adoral surface.
• Apical disc anterior, form unknown.
• Petals short, of equal length, interporiferous zones almost twice the width of poriferous zones, poriferous zones of the same petal of unequal length. Petals closing distally; pore-pairs conjugate, outer pores transversely elongate, inner pores round.
• Peristome subcentral and subpentagonal.
• Periproct inframarginal on rostrate extremity, longitudinally ovate.
• Phyllodes unknown.
• Bourrelets absent with a distinct well leading to the peristome opening.
• Buccal pores unknown.

Late Cretaceous (Upper Santonian) of Poland.

Rostropygus annae Szorenyi, 1955, p. 68; by original designation.

• Only the type species.

Irregularia; Cassiduloida; indeterminate.

Kier (1962, p. 104) comments that after seeing a cast and photographs of the holotype, he believes that the type species is so similar in petal arrangement and shape to Parapygus that the projecting posterior margin is not of sufficient importance to warrant the maintenance of a separate genus. However, as the features of the apical disc and phyllodes are unknown, this genus cannot be placed with any degree of certainty and must remain incertae sedis.

E. Szorenyi. 1955. Echinides Cretaces de la Bakony. Geologica Hungarica., series Palaeontologica, 26, 268 pp., 22 pls.

P. M. Kier. 1962. Revision of the cassiduloid echinoids. Smithsonian Miscellaneous Collections, 144 (3) 262 pp.