The Echinoid Directory

Eogaleropygus Jesionek-Szymanska, 1978, p. 191

Diagnostic Features
  • Test subpentagonal; as wide as long or slightly elongate; depressed, ambitus low; oral surface depressed towards peristome
  • Apical central, opening moderately large; plating lost. Disc not elongate (distance separating anterior and posterior paired ambulacra not large). Periproct opening into a small but distinct anal sulcus that extends more or less to the posterior ambitus.
  • Ambulacra not petaloid aborally; pore-pairs small, uniserial, decreasing slightly in size towards ambitus. Uniserial on oral surface with no crowding; all plates simple, but becoming organized into triads towards the peristome.
  • Peristome large and depressed with inturned walls; central; oblique with long axis running from interambulacrum 3 to ambulacrum I.
Distribution Middle Toarcian, Morocco
Name gender masculine
Type Pygaster microstomata Lambert, 1933, p. 54, by original; designation.
Species Included     Only the type species.
Classification and/or Status Euechinoidea, Irregularia, Menopygidae.

Subjective junior synonym of Menopygus Pomel, 1883.
Remarks The type species was originally placed in Pygaster by Lambert 1933, but its peristome is small, slightly oblique and lacking obvious buccal notches.  Also it has slightly elongate (subpetaloid) ambulacral pore-pairs aborally.  In creating the genus Eogaleropygus, Jesionek-Szymanska (1978) made no comparison with Menopygus from which it differs only in having a slightly less well-developed subanal groove.  The two are synonymized here.

Jesionek-Szymanska, W. 1978. On a new galeropygid genus (Echinoidea) from the Jurassic (Upper Lias) of Morocco. Acta Palaeontologica Polonica 23, 187-192, pls 13, 14.

Lambert, J. 1933. Echinides fossiles du Maroc. Notes et Memoires au Service des Mines 27, 27-79.