The Echinoid Directory

Contributed by Dinesh Srivastava, May 2009

Echinolampas garoensis Srivastava, Singh, Tiwari & Jauhri, 2008; p. 514

Diagnostic Features
  • Test large, subpentagonal, anterior ambitus broadly rounded, truncated posteriorly; oral surface flat; highest point of the test at centre.
  • Apical system monobasal, circular, excentric anteriorly.
  • Petals long, open, subpetaloid to straight and almost reaching the ambitus; III straight, shortest and narrowest; I & V subpetaloid, longest and broadest; poriferous zones of Ia, IIb, IIIa IVa and Vb are shorter than their fellows. Pore pairs are conjugated by straight to slightly curved grooves and single row of four to six small tubercles is present  between each pore pairs.
  • Peristome pentagonal with steep sides, excentric anteriorly and lies in a depression. Bourrelets and phyllodes (nucleolitid type) well developed.
  • Periproct larger than the peristome, inframarginal close to the posterior ambitus, transversally oval.
  • Tubercles abundant, non-perforate and crenulate.
Distribution Siju Limestone Formation (late Lutetian to early Bartonian); Dhapsagiri village, South Garo Hills, Meghalaya, India
Type Holotype LUGD/I/2020; Paratypes  LUGD/I/2020a , Geology Department Museum, Centre of Advanced Study in Geology, University of Lucknow, Lucknow.
Classification and/or Status Cassiduloida; Echinolampadidae

A species of Echinolampas (Echinolampas) Gray, 1825
Remarks Echinolampas garoensis differs from E. omanensis Clegg described from the early Eocene sediments of Oman (Clegg, 1933) in having subpentagonal test and petaloid to straight ambulacra besides, higher test. It differs from E. damesi Duncan & Sladen described from the Eocene sediments of Kachchh, India (Duncan & Sladen, 1883; Srivastava & Singh, 1999) in having subpentagonal test, higher test and crenulated tubercles; from E. discoideus d'Archiac described from the Oligocene sediments of Sind, Pakistan (Duncan & Sladen, 1882-1886) in having very high subpentagonal test and anteriorly excentric peristome; from E. lycopersicus Guppy reported from the middle Tertiary sediments of Puerto Rico (Gordon, 1963) in having subpetaloid to straight petals and pentagonal peristome. E. garoensis resembles E. gregoryi  McNamara & Philip recorded from the middle Miocene sediments of Southern Australia (McNamara & Philip, 1980) but differs in having excentric pentagonal peristome besides wide and subpetaloid to straight petals.

Clegg, E. L. G., 1933. Echinoidea from the Persian Gulf. Palaeontologica Indica (New Series), 22 (1): 11-12, pl.1, figs. 5a, b, c.

Duncan, P. M. and Sladen, W. P., 1882 - 1886. Fossil Echinoidea of Western Sind and the Coast of Biluchistan and of the Persian Gulf, from Tertiary formations. Palaeontologica Indica; Series 14, 1(3): 392 p., 58 pls.

Duncan, P. M.&  Sladen, W. P. 1883.The fossil Echinoidea of Kutch and Kattywar. Palaeontologica Indica,  Series 14 1(4): 104 pp., 13 pls.

Gordon, W. A., 1963. Middle Tertiary echinoids of Puerto Rico. Journal of Paleontology, 37(3): 628-642.

McNamara, K. J. & Philip, G. M., 1980. Tertiary species of Echinolampas (Echinoidea) from southern Australia. Memoirs of the National Museum, Victoria, 41: 14 pp., 4 pls.

Srivastava, D. K. & Singh, S. K., 1999. Echinolampas - a cassiduloid echinoid from the Tertiary rocks of Kachchh, India. Journal of the Palaeontological Society India, 44, 25-47.

Srivastava, D. K., Singh, A. P., Tiwari, R. P. & Jauhri, A. K., 2008. Cassiduloids (Echinoidea) from the Siju Formation (late Lutetian-early Bartonian) of the South Garo Hills, Meghalaya, India. Revue de Palaeobiologie, Geneve (Switzerland), 27(2), 511-523.