The Echinoid Directory

Lymanaster Lambert, 1920, p. 162

Diagnostic Features
  • Test cordiform, with well defined anterior sulcus; posterior face truncate. Test wedge-shaped in profile.
  • Apical disc ethmolytic with three gonopores (no gonopore in G2); posterior of centre.
  • Anterior ambulacrum sunken from apex. Pore-pairs well developed, with funnel-building tube-feet; arranged uniserially.
  • Petals well developed; sunken; extending almost to ambitus. The anterior pair long and flexed anteriorly, the posterior about half the length, widely divergent.
  • Peristome close to anterior border and facing forward into frontal groove. Labral plate projecting to cover peristome in oral view.
  • Plastron plating with rather narrow, mushroom-shaped labral plate not projecting beyond first ambulacral plate.
  • Periproct small, on posterior truncate face.
  • Peripetalous fasciole present; passing around base of petals and deeply indented between petals. Lateroanal fasciole absent in adults.
Distribution
Recent, west coast of North America.
Name gender masculine
Type
Schizaster townsendi Agassiz, 1898, p. 82; by original designation.
Classification and/or Status

Spatangoida, Paleopneustina, Schizasteridae.

Subjective junior synonym of Brisaster Gray, 1855.

Remarks
This taxon was established by Lambert in 1920, but he quickly abandoned it, as it is not mentioned in Lambert & Thiery (1924). Other than in the complete absence of a lateroanal fasciole in adults, this taxon is identical to the type of Brisaster.

Lambert, J., in Castex, L. & Lambert, J. 1920. Revision des echinides des falaises de Biarritz. Actes de la Societe linnee de Bordeaux 71, 117-206, 2 pls.