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.