The Echinoid Directory

Camerogalerus Quenstedt, 1873, p. 411

[=Pithodia Pomel, 1883, p. 75 (objective); =Pseudodiscoides Lambert & Thiery, 1914, p. 282 (objective); = Dixonia Wagner & Durham, 1964, p. 170, type species Discoidea minima Desor, 1842 ]

Diagnostic Features
  • Generally large, up to 60 mm in diameter.
  • Apical disc with five subequal genital plates, all of which are covered in hydropores.
  • Ambulacra simple near the apex, becoming trigeminate around the ambitus and adorally.
  • Upper and lower elements in each triad compound plate are reduced in size and occluded from the midline.
  • Narrow blade-like internal ridges run from the peristome to the ambitus along the adradial margins of interambulacral zones.
  • Peristome small and central.
  • Periproct always oral and relatively small.
  • Lower surface flat in medium to large species (but not in C. minimus).
Distribution
Early Cretaceous (Aptian) to Late Cretaceous (Maastrichtian), Europe and North Africa.
Name gender masculine
Type
Galerites cylindricus Lamarck, 1816, p. 23, by monotypy.
Species Included
  • C. conica (Desor, 1842); Late Albian, France.
  • C. forgemolli (Coquand, 1862); Cenomanian of Algeria.
  • C. peroni (Lambert, 1892); Late Aptian of France, Albian of England.
  • C. cylindricus (Lamarck,1816); Late Albian to Late Cenomanian, western Europe [includes C. bucaillei Lambert & Jeannet, 1928; Discoidea concava Bucaille, 1883; Discoidea favrina Desor, 1842].
  • C. minimus (Desor, 1842); Latest Cenomanian to Coniacian, England and France [includes Discoides infera Desor, 1857].
  • C. cantabricus Smith & Gallemi 1999; Early Maastrichtian, Santander, Spain.
  • C. neglectus (Lambert, 1931); Santonian, Tunisia,
Classification and/or Status

Holectypoida, Holectypidae, Discoidinae.

Probably paraphyletic, by omission of Discholectypus

Remarks

The type species is common in the Middle and Late Cenomanian chalks of the Anglo-Paris basin. The apical disc, with all five genital plates pierced by the many small pores of the madreporite, is highly characteristic. Discoidea minima, the type of Dixonia, differs from the type species of Camerogalerus in having a a more rounded profile but is otherwise very similar. Holectypus meslei, the type of Discholectypus, differs from the type species in having trigeminate plating extending closer to the apex and in having a more complicated arrangement of larger and smaller compound plates adorally. Discoides differs in having four gonopores and hydropores confined to genital plate 2.

Quenstedt, F. A. 1872-1875. Petrefactenkunde Deutschlands. 1 Abt., 3. Echinodermen (Echinoiden), 719 pp., 28 pls. Fues's Verlag, Leipzig.

Smith, A. B. & Wright, C. W. 1999. British Cretaceous Echinoids. Part 5, Holectypoida, Echinoneoida. Palaeontographical Society Monographs, 343-390, pls 115-129.