The Echinoid Directory

Hemipatagus Desor, 1858, p. 416

[=Tuberaster Peron & Gauthier, 1885, p. 46, type species Tuberaster tuberculatus Peron & Gauthier, 1885; =Chuniola Gagel, 1903, type species Chuniola carolinae Gagel, 1903 ]

Diagnostic Features
  • Test ovate with distinct anterior sulcus; posterior face truncate. Test low domal in profile.
  • Apical disc ethmolytic with four gonopores; central. Genital plate 2 projects well beyond posterior ocular plates. Gonopores positioned close to centre.
  • Anterior ambulacrum depressed; pore-pairs small and simple.
  • Paired ambulacra petaloid aborally and flush; closing distally.
  • Anterior column of pore-pairs rudimentary adapically and sigmoidally curved, Posterior petals almost as long as anterior petals.
  • Peristome ovate and downward-facing; without projecting labrum.
  • Labral plate longitudinally elongate; extending to second ambulacral plate. Sternal plates triangular, with tubercles confined to posterior half.
  • Sternal-episternal suture V-shaped.
  • Ambulacral plate 6 in posterior ambulacra L-shaped and first to extend into subanal fasciole.
  • Periproct on posterior truncate face; wider than tall.
  • Bilobed subanal fasciole present.
  • Large primary tubercles in anterior and lateral interambulacral zones; areoles sunken.
  • Tubercles on lateral interambulacra on oral surface large, weakly sunken and linearly arranged.
Middle Eocene to Oligocene, ?Miocene, North America, Europe and North Africa.
Name gender masculine
Hemipatagus hoffmanni Desor, 1858, p. 416, (=Spatangus hoffmanni Goldfuss, 1826, p. 152), by original designation.
Species Included
  • H. hoffmani (Goldfuss, 1826); Oligocene, Germany.
  • H. subrostrata Clark, in Clark & Twitchell, 1915; Middle Eocene, SE USA.
  • H. gauthieri Lambert, in Lambert & Thiery, 1921; Oligocene, Algeria.
  • H. pellati Cotteau, 1863; Lower Oligocene, France.
  • H. grandituberculatus (Lewis, 1989); Upper Eocene, UK.
  • ? H. carolinae Gagel, 1903; Lower Miocene, Germany.
  • ?H. carinata (Cotteau, 1891); Eocene, Spain.
Classification and/or Status

Spatangoida, Micrasterina, Loveniidae.

Possibly paraphyletic.

Differs from Lovenia only in lacking an internal fasciole and in having more lanceolate petals. In some ways intermediate between Maretia and Lovenia. Chuniola though currently too poorly known to be placed in synonymy with confidence, has an almost identical upper surface.

Desor, E. 1855-1858. Synopsis des échinides fossiles, lxviii + 490 pp., 44 pls. Reinwald, Paris.