The Echinoid Directory

Hypselaster H. L. Clark, 1917, p. 185

Diagnostic Features
  • Test ovate with deep anterior sulcus; posterior truncated; inflated in profile.
  • Apical disc ethmolytic, with just 2 gonopores (missing from anterior genital plates); subcentral.
  • Anterior ambulacrum deeply sunken; pore-pairs and tube-feet specialized and in single series.
  • Other ambulacra also deeply sunken, anterior petals longer and more flexed than posterior petals.
  • Periproct small and marginal, on near-vertical truncate face; opening between plates 5 and 8 in posterior interambulacrum.
  • Peristome large, reniform.
  • Labral plate longer than wide, extending no further than second ambulacral plate in type species (not beyond first ambulacral plate in other species); in broad contact with sternal plates. Sternal plates symmetrical. Episternal plates paired.
  • Aboral tuberculation fine, uniform and dense. Oral tubercles also dense and uniform.
  • Well-developed peripetalous fasciole. Latero-anal fasciole usually only present in the subanal region; missing laterally.
Eocene to Recent, Caribbean and Indo-Pacific.
Name gender masculine
Schizaster (Periaster) limicola A. Agassiz, 1878, p. 193, by original designation.
Species Included
  • H. limicolus (Agassiz, 1878); Recent, Gulf of Mexico.
  • H. rotundus (Agassiz & Clark, 1907); Recent, Japan.
  • H. jukesii (Gray, 1855); Recent, Australia.
  • H. dolosus Clark, 1938; Recent, Australia.
  • H. brachypetalus Clark, 1917; Recent, Caribbean.
  • H. kempi (Koehler, 1914); Recent, Indian Ocean.
  • H. maximus (Agassiz & Clark, 1907); Recent, Hawaii.
  • H. fragilis (Agassiz & Clark, 1907); Recent, Japan.
  • H. affinis Mortensen, 1948; Recent, Philippines.
  • H. obliquatus (Sowerby, in Grant, 1840); Eocene, India
  • H. rajasthanensis Srivastava & Kulshreshtha, 2009; Eocene, India
  • Hypselaster sp. Lachkem & Roman, 1995; Upper Miocene, Morocco.
Classification and/or Status

Spatangoida, Paleopneustina, Schizasteridae.



Ova also has two gonopores but differs in having a complete lateroanal fasciole. Hypselaster contains schizasterids in which the lateroanal part of the marginal fasciole is greatly reduced, with traces only remaining in the posterior interambulacrum on plates 4 and 5. This is exactly the situation seen in Gregoryaster, however, that genus has four, not two, gonopores.

Clark, H. L. 1917. Hawaiian and other Pacific Echini. Memoirs of the Museum of Comparative Zoology, Harvard College, 46, 85-283.

Mortensen, T. 1951 A monograph of the Echinoidea. V, Spatangoida 2. C. A. Reitzel, Copenhagen.