The Echinoid Directory

Brachybrissus Pomel, 1883, p. 37

Diagnostic Features
  • Test ovate with anterior sulcus; rounded in profile.
  • Apical disc ethmolytic, four gonopores.
  • Anterior ambulacrum sunken adapically; pore-pairs in single column series.
  • Other ambulacra also deeply sunken, anterior petals much longer and more flexed than posterior petals.
  • Periproct small and marginal, on near-vertical truncate face.
  • Peristome labiate; wider than long.
  • Labral plate short and wide; in broad contact with sternal plates; not reaching start of ambulacral plate 2 at rear.
  • Plastron wide and ovate, episternal plates not paired and opposite and not forming significant part of plastronal area.
  • Aboral tuberculation fine, uniform and dense.
  • Well-developed peripetalous and latero-anal fascioles.
Distribution
Eocene to Miocene, Circum-Mediterranean.
Name gender masculine
Type
Spatangus ambulacrum Deshayes , 1831, p. 255; by original designation.
Species Included
  • Lambert & Thiery (1924, p. 527) included 12 other species in this taxon.
Classification and/or Status

Spatangoida, Paleopneustina, Schizasteridae.

?Subjective junior synonym of Schizaster Agassiz, 1836.

Remarks
The number of gonopores in this species, as reported by Cotteau (1885-1889) is "possibly four", although Lambert & Thiery (1921) record it as having two. A specimen in the de Loriol collection appears to have four gonopores.

Pomel, A. 1883. Classification méthodique et genera des Échinides vivante et fossiles. Thèses présentées a la Faculté des Sciences de Paris pour obtenir le Grade de Docteur ès Sciences Naturelles, 503, 131 pp. Aldolphe Jourdan, Alger.