The Echinoid Directory

Contributed by Andrew Smith, April 2008

Orthechinus Gauthier, 1889, p. 105

Diagnostic Features
  • Apical disc relatively small, plating missing
  • Ambulacra trigeminate with uniserial pore-pairs; plate compounding diadematid with primary tubercle overlapping all elements
  • Interambulacra with primary tubercle flanked by interradial smaller secondary tubercle.  No adapical naked zone interradially
  • Buccal notches rather well developed.
  • Tubercles imperforate and crenulate
Distribution Upper Cretaceous (Senonian), North Africa and the Middle East; possibly more widely distributed
Name gender masculine
Type Orthechinus tunetanus Gauthier, 1889, by original designation.
Species Included
  • O. tunetanus Gauthier, 1889; Late Cretaceous, Tunisia.
  • O. cretaceus Cotteau & Gauthier, 1895; Late Cretaceous, Iran. [includes O. cotteaui Gauthier, 1902; Late Cretaceous, Iran] may be synonymous - see O. cotteaui for a well preserved individual.
Remarks Gauthier, V. 1889. Description des échinides fossiles recueillis en 1885 et 1886 dans la région sud des hautes-plateaux de la Tunisie, par M. Philippe Thomas. Exploration scientifique de la Tunisie, Géologie, Paléontologie, 116 pp., 32 pls. Imprimerie Nationale, Paris.