The Echinoid Directory

• Test ovate with deep anterior sulcus; posterior face truncate. Test depressed in profile; ambitus rounded.
• Apical disc ethmophract with four gonopores; posterior of centre.
• Ambulacrum III deeply sunken aborally; wide and with vertical walls which converge towards the ambitus so that the groove is pinched adambitally. Pore-pairs uniserial.
• Petals sunken; anterior petals long and flexed anteriorly; posterior petals less than half the length of the anterior petals and only weakly depressed.
• Ambulacral zones strongly pinched immediately beneath petals where they pass through the fasciole.
• Peristome close to anterior border and facing forward into frontal groove. Labrum projecting to cover peristome in oral view.
• Plastron plating with triangular labral plate and symmetrical sternal plates. Episternal plates offset.
• Periproct on posterior truncate face.
• Peripetalous fasciole present.

Upper Cretaceous (Upper Campanian to Maastrichtian), Europe, former Soviet Union, North Africa, Middle East.

Schizaster atavus Arnaud in Cotteau, 1883, p. 13, by original designation.

• P. atavus (Arnaud, in Cotteau, 1883); Campanian, France.
• P. geayi Cottreau, 1908; Upper Campanian and Maastrichtian, Madagascar, Arabian Peninsula, Libya.
• P. morgani (Cotteau & Gauthier, 1895); Campanian or Maastrichtian, Iran.
• P. centrosus (Cotteau & Gauthier, 1895); Campanian or Maastrichtian, Iran.
• P. douvillei (Gauthier, 1902); Senonian, Iran.
• P. granti Kier, 1972; Campanian, Saudi Arabia.

Spatangoida, Hemiasterina, Hemiasteridae.

Monophyletic?

Proraster resembles Holanthus in having highly pinched ambulacral zones beneath the petals, but that genus has only a shallow anterior groove. The deeply sunken frontal groove and flexed anterior petals make Proraster look like a Brisaster or Paraster, but it is distinguished from both by its ethmophract apical disc and absence of a latero-anal fasciole.

Kier, P. M. 1972. Tertiary and Mesozoic echinoids of Saudi Arabia. Smithsonian Contributions to Paleobiology 10, 1-242.

Lambert, J. 1895, Essai d'une monographie du genere Micraster et notes sur quelques échinides. Pp. 149-267. In de GROSSOUVRE, A. (ed.) Recherches sur la Craie supérieure. Mémoires du Service de la Carte géologique de France 1 (Chapitre IV).

Smith, A. B. 1995. Late Campanian-Maastrichtian echinoids from the United Arab Emirates-Oman borders region. Bulletin of the Natural History Museum, London (Geology Series) 51, 121-240.