The Echinoid Directory
Contributed by Dinesh Srivastava, July 2010
Plerisalenia jaisalmerensis (Sahni and Bhatnagar in Sahni, 1955, p. 187)
[1955 Hemicidaris jaisalmerensis Sahni & Bhatnagar, p. 187.
1980 Recrosalenia jaisalmerensis (Sahni & Bhatnagar); Bhatia, p. 39.
2010 Acrosalenia jaisalmerensis (Sahni & Bhatnagar); Srivatava et al. 2010, p. 59. ]
| Distribution | Middle Jurasiic (Bathonian) Fort Member, Jaisalmer Formation of Jaisalmer, Rajasthan, India. |
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| Type | Holotype: GSI Type No. 17634; paratypes - GSI Type No. 17635-17638 Curatorial Division, Geological Survey of India, Kolkata, India. |
| Classification and/or Status | Calycina, Salenioida; stem group Salenioida A species of genus Perisalenia Valette, 1906 |
| Remarks | A. arabia Kier, 1972, from the Bathonian of Saudia Arabia, differs from A. jaisalmerensis by its higher number of interambulacral plates, which are comparatively low and border 3 to 5 ambulacral demiplates only at the ambitus. A. bowersi Kier, 1972, from the Bathonian of Saudia Arabia, differs in its apical disc with 4 or more suranal plates, low interambulacral plates (bordering 3 to 4 ambulacral plates at ambitus), higher number of interambulacral plates per column and its smaller interambulacral primary tubercles adapically and at the ambitus. A. dhrumaensis Kier, 1972, from the Bathonian of Saudia Arabia, differs in its single, central suranal plate and lower interambulacral plates. A. gananensis Stefanini 1931 from the Jurassic of Somalia differs in its high test, much more posteriorly elongated apical disc and presence of naked interradial zones adapically. A. lemoinei Lambert in Lambert and Lemoine, 1908, from the Jurassic of Madagascar is distinguished by its single suranal plate, more elongate apical disc and high number of interambulacral plates per column. A. marratensis Kier, 1972, from the Toarcian of Saudia Arabia, differs in its well separated areoles and more posteriorly elongated apical disc. A. microstoma Lambert in Besairie, 1936 from the Bathonian of Madagascar differs by its much smaller peristome (only ~23 % of test diameter). A. (Metacrosalenia) quadrimiliaris Currie, 1927, from the Jurassic of Somalia and A. (Metacrosalenia) pseudocidaroides Currie, 1925, from the Middle Jurassic of Somalia and Ethiopia, differs from A. jaisalmerensis in its sinuous ambulacra, larger interambulacral tubercles with deep areoles that are well separated at the ambitus, and its high interambulacral plates which border 10+ demiplates ambitally. A. somaliensis Currie, 1925, from the Lower Jurassic of Somalia, differs in its single, central suranal plate and its complete lack of enlarged interambulacral tubercles adapically. Bhatia, S. B. 1980. Taxonomic comments on Hemicidaris jaisalmerensis from the Jurassic of Jaisalmer, Rajasthan, India. Bulletin of the Indian Geologists' Association 13(1): 39-43. Sahni, M. R. 1955. Recent Researches in the Palaeontologic Division, Geological Surey of India. Current Science 24(6): 187-188. Srivastava, D. K., Kroh, A. & Kulshreshtha, S. K. 2010.Taxonomic revision of a hemicidarid echinoid Hemicidaris jaisalmerensis Sahni and Bhatnagar, 1955. Journal of the Palaeontological Society of India 55(1), 59-64. |