The Echinoid Directory

Contributed by Dinesh Srivastava, March 2010

Megapneustes jaisalmerensis Srivastava et al., 2008; p. 32

Diagnostic Features	Test large, heart shaped with moderate frontal sinus; aboral surface dome shaped; oral surface flat; apical system anteriorly eccentric, ethmolytic, monobasal; petals long, subpetaloid, ambulacral plates simple (occluded plates absent); peristome labiate, anteriorly eccentric kidney shaped; periproct inframarginal at the posterior truncation.
Distribution	Early Eocene, Rajasthan, India.
Type	Holotype: GU/R/KE/2023; Paratype Nos. GU/R/KE /2024 to GU/R/KE/2026 and GU/R/KE /F 2027-31; Laboratory of Vertebrate Palaeontology, Department of Geology, HNB Garhwal University, Srinagar (Garhwal), Uttaranchal, India.
Classification and/or Status	Order Spatangoida Claus, 1876; Family Brissidae Gray, 1855. A species of Megapneustes Gauthier, 1899
Remarks	Megapneustes jaisalmerensis is close to the M. grandis Gauthier, 1899 from the Eocene of Egypt (Gauthier, 1899) but differs from the latter in having a heart shaped test, monobasal apical system, long, subpetaloid, ambulacral petals which reach almost up to the ambitus whereas the Egyptian species has an oval test with straight ambulacral petals which do not reach to the ambitus and a tetrabasal apical system. Gauthier in Fourtau, R. 1899. Revision des echinides fossiles de l'Egypte. Memoires de l'Institut egyptien, 3(8), 605-740, pls 1-4. Srivastava, D. K., Rana, R. S. & Hukam Singh, 2008. Record of Megapneustes Gauthier (brissid echinoid) from the Khuiala Formation, Jaisalmer district, Rajasthan, India. Journal of the Palaeontolgical Socity of India 53, 31-36.