The Echinoid Directory

Balanocidaris Lambert, 1910, p. 4

Diagnostic Features	Test relatively thick shelled. Ambulacra weakly sinuous; primary tubercle to each plate forming contiguous vertical series, tuberculation uniform to peristome. Interambulacral plates with large primary tubercle. Tubercle has a large mamelon with a rudimentary perforation and a non-crenulate platform; areole circular and incised. Scrobicular tubercles differentiated; extrascrobicular granulation fine, uniform and dense; forming only a very narrow interradial band. Spines large, stout and fusiform with short neck and globular head tapering rapidly to a distal point. Shaft ornamented with beaded ribs but tip with more irregular granulation. Base non-crenulate.
Distribution	Upper Jurassic, Europe, North Africa and the Near East.
Name gender	feminine
Type	Cidaris glandifera Munster, in Goldfuss, 1826, by original designation.
Species Included	B. glandifera Munster in Goldfuss, 1829; Oxfordian to Tithonian, Europe, North Africa and the Near East. B. propinqua (Munster, in Goldfuiss, 1829); Oxfordian, Europe.
Classification and/or Status	Cidaroida, Psychocidaridae. Unknown.
Remarks	Although this taxon was established only on the basis of its distinctive spine morphology it remains a valid taxon. Vadet & Wille (2002) have described a complete test. Caenocidaris differs only in having slightly more pointed spines with a coarser ornament, finer scrobicular tubercles and more incised areoles but is otherwise very similar. It is possibly only worth distinguishing Caenocidaris at subgenus level. Tylocidaris differs from Balanocidaris in having much better developed extrascrobicular zones. Furthermore, it is only rarely that adapical tubercles in Tylocidaris retain traces of a rudimentary perforation, whereas ambital and adapical tubercles of Balanocidaris always have a small perforation. Lambert, J. 1910. Les echinides des Iles Snow-Hill et Seymour. Wissenschaftliche Ergebnisse der Schwedischen Sudpolarexpedition 1901-1903, 3, 1-15. Vadet, A. & Wille, E. 2002. Quelques oursins du Lusitanien du Portugal. Annales de la Societe d'Histoire Naturelle du Boulonnais 2(1), 8-18.