The Echinoid Directory

Mercieripygurus Vadet, 1997, p. 58

Diagnostic Features
  • Test large, circular, flat, oral surface slightly depressed towards peristome.
  • Apical system subcentral, tetrabasal, with four gonopores.
  • Petals open, extending almost to ambitus, inner pore rounded, outer pore very transversely elongated, all ambulacral pores double beneath the petals.
  • Periproct inframarginal, close to posterior margin, subtrigonal.
  • Peristome pentagonal, small, slightly anterior to centre, equant.
  • Bourrelets moderately developed.
  • Phyllodes double pored, with an inner and an outer series, every other pore in the outer series being offset, giving the impression of being arranged in arcs of three.
  • No buccal pores.
  • Primary tubercles perforate, larger on the on adoral surface than those on adapical surface; no naked zone in posterior interambulacrum.
Distribution
Middle Jurassic (Bathonian-Oxfordian) of England and France.
Name gender masculine
Type
Clypeaster hausmanni Koch & Dunker, 1837, p. 38; by original designation of Vadet, 1997, p. 58.
Species Included
  • Only the type species.
Classification and/or Status

Irregularia; Neognathostomata.

Subjective junior synonym of Astrolampas Pomel, 1883.

Remarks

Vadet (1997, p. 48) does not give a clear diagnosis by which to distinguish the type specie of this genus from the type species of Astrolampas. Given their similar appearance and phyllode structure, Mercierpygurus is here treated as a subjective junior synonym of Astrolampas.

A. Vadet. 1997. Echinides du Callovien de la Sarthe et de l'Orne. II. A les echinides irregulies: analyse et evolution. Memoires de la Societe Academique du Boulonnais Serie Histoire Naturelle, 18 (1), 1-72.