The Echinoid Directory

Contributed by Jenna Sullivan, May 2007

Conulus triadis Lees, 1928, p. 659.

Diagnostic Features "A large species with rounded or slightly pentagonal outline, aboral surface with straight vertical sides for about half the height, the upper half being hemispherical, slightly carinate in the posterior interambulacrum; oral surface perfectly flat, ambitus sharp, test thin, tuberculation of areas alike, coarser below; periproct marginal. Apical disc tuberculate; poriferous zones congested, strongly triserial orally." (Lees, 1928, p. 660)
Distribution Upper Cretaceous (Senonian - Campanian) of Oman.
Type Holotype: Natural History Museum E18323.
Classification and/or Status Species of Conulus.
Remarks "Closely allied with Conulus douvillei (Coutteau & Gauthier), however C. douvillei's shape is somewhat different, the ambitus being more rounded and the base less flat. It lacks the tubercles and granules in the apical disc; the interamblacral plates have also fewer granules, and they lack the downward deflection near the junction. C. carcharias (Coquand) resembles C. triadis in shape but differs in details of ornament: the tubercles are fewer, and the sutures of the interambulacral plates are straight rather than deflected downwards." (Lees, 1928, p. 660).

Lees, G.M. 1928. The Geology and Tectonics of Oman and of Parts of south-Eastern Arabia. Quarterly Journal of the Geological Society, London, 84(4): 659, pl. XLVI.