The Echinoid Directory

Studeria Duncan, 1889, p. 185

[ =Hypselolampas H. L. Clark, 1917, p. 104, type species Studeria recens A. Agassiz, 1879; = Tristomanthus Bittner, 1892, p. 41, type species Nucleolites subcarinatus Goldfuss, 1826, p. 142]

Diagnostic Features
  • Test of small to medium size, elongate, inflated, with a smoothly rounded anterior margin and a slightly pointed or slightly truncated posterior margin. Oral surface depressed towards peristome.
  • Apical system anterior, monobasal, with three genital pores, no pore in the left anterior genital plate.
  • Petals long, open, straight, extending almost to margin; adjacent pore pairs widely spaced, ambulacral plates beyond petals single pored.
  • Peristome subcentral to slightly anterior, longer than wide.
  • Periproct marginal, longitudinal, with short anal sulcus.
  • Bourrelets moderately developed, weakly indenting peristome margin.
  • Phyllodes slightly widened, single pored, n two series in each half-ambulacrum with with few pores in inner series
  • Buccal pores present.
  • Tubercles slightly larger adorally, no naked granular zone in interambulacrum 5.
  • Oligocene to Recent of Europe, India, Hawaii and Australia.
Name gender feminine
Catopygus elegans Laube, 1869, p. 8; by monotypy.
Species Included
  • S. elegans (Laube, 1869); Miocene, Australia.
  • S. recens (A. Agassiz, 1879); Recent, India, Hawaii.
  • S. subcarinata (Goldfuss, 1826); Oligocene, Germany.
Classification and/or Status
Irregularia; Cassiduloida; Neolampadidae.

Studeria is similar to Pliolampas, both genera have open petals, three genital pores, with no pore in the left anterior genital plate, similar phyllodes and a longer than wide peristome (Kier, 1962, p. 217). Studeria can be distinguished from Pliolampas by its marginal periproct (inframarginal in Pliolampas).

Duncan, P. M. 1889. Revision of the Echini. Journal of the Linnean Society, Zoology 23,

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