The Echinoid Directory

Cosmocyphus Pomel, 1883, p. 91

[?=Euporophyma Gauthier, in Fourtau, 19901, p. 59, type species Coptosoma lefebvrei Gauthier, in Fourtau, 1901; =Gauthiosoma Kutscher, 1985, p. 524, type species Cidarites princeps von Hagenow 1840 ]

Diagnostic Features
  • Test wheel-shaped, depressed above and below.
  • Apical disc large, pentagonal, less than half test diameter in length, extending slightly into posterior interambulacrum. Plates not bound to corona, always missing; presumed monocyclic.
  • Ambulacra straight; plating polygeminate (5-6 elements to a plate), compounded in phymosomatid style. Pore-pairs undifferentiated; arranged into weak arcs across entire oral surface and most of aboral surface except close to apex where they become biserially arranged. No phyllodes.
  • A single primary tubercle to each compound plate; additional small secondaries and granules forming zig-zag line down perradius.
  • Interambulacral plates wider than tall; with a single primary tubercle, positioned centrally and scattered secondaries and granules interradially at the ambitus, but a well developed naked interradial zone present aborally, expanding towards the apex. In largest specimens there may be a small secondary tubercle flanking the primary on aboral plates.
  • Tubercles imperforate and crenulate with massive mamelon; on ambital and adoral plate the areole and lower part of boss typically radially striated.
  • Peristome small, circular, rather deeply sunken, with small, but clearly defined buccal notches with thickened lip; no tag.
  • No sphaeridial pits; no basicoronal interambulacral plate.
  • Spines and lantern unknown.
Distribution
Upper Cretaceous (Campanian-Maastrichtian) - Palaeocene, Europe, central Asia: possibly also Turonian, Egypt.
Name gender masculine
Type
Cyphosoma saemanni Coquand, 1860, p. 1014, by subsequent designation of Lambert & Thiery, 1910, p. 223.
Species Included
  • C. saemanni (Coquand, 1860); Upper Campanian, Europe.
  • C. princeps (Hagenow, 1840); Campanian-Maastrichtrian, Europe.
  • C. krimica (Weber, 1934); Maastrichtian of Belgium and Denmark; Danian of Poland, Ukraine and the Crimea, Turkmenia and Kazakhstan.
  • ?C. lefebvrei Gauthier, in Fourtau, 1901; Turonian, Egypt, India.
Classification and/or Status
Euechinoidea, Phymosomatoida, Phymosomatidae.
Remarks
Distinguished from Phymosoma by (i) less well developed adapical zone of biserial pore-pairs (ii) deeply sunken peristome (iii) no phyllodes. Close to Gauthieria, but in that genus the pore-pairs remain strictly uniserial to the apex. However, all Gauthieria species are small and this may simply be a size-related feature.

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, Aldolphe Jourdan, Alger, 131 pp.