The Echinoid Directory

Neoproraster Markov, 1994, p. 82

Diagnostic Features
  • Test cordiform, with deep anterior sulcus; posterior face truncate. Test depressed in profile.
  • Apical disc ethmolytic with three gonopores (no gonopore in G2); slightly posterior of centre.
  • Anterior ambulacrum sunken from apex. Pore-pairs well developed and arranged uniserially
  • Petals rather narrow, weakly sunken. The anterior flexed towards the anterior, the posterior very much shorter and a little less strongly depressed.
  • Peristome close to anterior border and facing towards the anterior; almost vertical.
  • Plastron plating with short, mushroom-shaped labral plate not projecting beyond first ambulacral plate. Sternal plates symmetrical. Episternal plates forming rear part of plastron; offset.
  • Periproct on posterior truncate face.
  • Peripetalous fasciole present; passing around distal ends of petals.
Distribution
Palaeocene, Kazakhstan.
Name gender masculine
Type
Neoproraster bajarunasi Markov, 1994, p. 85, by original designation.
Species Included
  • Markov included two species, N. bajarunasi Markov 1994 (Thanetian, Kazakstan), and N. usakensis Markov, 1994 (Danian, Kazakstan).
Classification and/or Status

Spatangoida, Paleopneustina, Schizasteridae.

Subjective junior synonym of Brisaster Gray, 1825.

Remarks

Differs from Schizaster and Ova in having three gonopores. Differs from Aceste in having petaloid ambulacra and three, not two gonopores.   Proraster has an ethmophract apical disc. Smith & Jeffery (2000) synonymized this taxon with Brisaster.

Markov, A. V. 1994. Morphology, systematics and phylogeny of schizasterid sea urchins. Trudy Paleontologicheskogo Instituta Rossiiskaya Akademiya Nauk 258, 94 pp, 4 pls [in Russian].

Smith, A. B. & Jeffery, C. H. 2000. Maastrichtian and Palaeocene echinoids: a key to world faunas. Special Papers in Palaeontology 63, 404 pp.