The Echinoid Directory

Iraniaster Cotteau & Gauthier, 1895, p. 26

Diagnostic Features	Test ovate with small but distinct anterior sulcus; short truncate posterior face. Lower surface weakly convex, upper surface vaulted. Apical disc ethmophract with four gonopores; genital plate 2 separating the posterior genital plates but not the posterior ocular plates. Positioned centrally. Anterior ambulacrum weakly depressed from apex to peristome; pore-pairs miniscule. Paired ambulacra petaloid; petals extending most of the way to the ambitus; weakly depressed with narrow interporal zone. Peristome small and circular; close to anterior border and facing obliquely forward towards frontal groove. Labral plate small and longitudinally elongate; extending to third ambulacral plate. Separated from sternal plate 5.b.2 by second ambulacral plates. Sternal plate 5.b.2 large and anterior to plate 5.a.2; subsequent plating biserial. Anterior paired interambulacra amphiplacous, lateral paired interambulacra meridoplacous. Periproct on short posterior truncate face; well below mid-height in posterior view. Peripetalous fasciole present, passing around the base of the petals.
Distribution	Upper Cretaceous (Campanian-Maastrichtian), Middle East.
Name gender	masculine
Type	Iraniaster morgani Cotteau & Gauthier, 1895, p.26, by original designation.
Species Included	I. morgani Cotteau & Gauthier, 1895; Campanian-Maastrichtian, Iran. I. omanensis Jeffery, 1999; Maastrichtian of Oman. I. affinimorgani Kier, 1972; Upper Campanian, Arabian Peninsula. I. affinidouvillei Kier, 1972; Upper Campanian, Arabian Peninsula. I. bowersi Kier, 1972; Upper Campanian, Arabian Peninsula.
Classification and/or Status	Spatangoida, Hemiasterina, Somaliasteridae. Presumed monophyletic.
Remarks	Kier (1972) gave a thorough and detailed description of this taxon and placed Somaliaster in synonymy. However, the disjunct nature of the plastron in Somaliaster separates that taxon and suggests closer relationship to the more derived Leviechinus and Brightonia which have similarly disjunct plastrons. Jeffery (1999) recently reviewed the Somaliasteridae. Cotteau, G. H. & Gauthier, V. 1895. Mission scientifique en Perse par J. de Morgan; études géologiques des échinides fossiles. Volume 3, 1-107. E. Leroux, Paris. Kier, 1972. Tertiary and Mesozoic echinoids of Saudi Arabia. Smithsonian Contributions to Paleobiology 10, 242 pp. Jeffery, C. H. 1999. A reappraisal of the phylogenetic relationships of somaliasterid echinoids. Palaeontology 42, 1027-1041.