The Echinoid Directory

• Test ovate with faint anterior sulcus; posterior face roundedly truncate. Test domed in profile.
• Apical disc ethmolytic with four gonopores; central.
• Anterior ambulacrum non-petaloid; weakly depressed towards ambitus. Pores small.
• Paired ambulacra petaloid; petals long and parallel, extending to ambitus; open distally; not sunken.
• Peristome D-shaped; far removed from the anterior; slightly sunken but predominantly downward-facing.
• Labral plate longer than wide; extending to rear of second ambulacral plate. Sternal plates triangular and fully tuberculate.
• Periproct on posterior truncate face.
• Subanal fasciole present; ovate.
• Peripetalous fasciole present; narrow and not indented behind anterior petals.
• Aboral tuberculation heterogeneous but without differentiated primary tubercles.

Eocene, North East Africa (Egypt, Somalia) and Arabian Peninsula.

Macropneustes ammon Desor, in Agassiz & Desor, 1847, p. 115, by original designation. Syntype: Museum National d'Histoire Naturelle, Paris, R62182.

• P. ammon Desor, 1847; Lower Eocene, Egypt.
• P. aff. ammon Kier, 1957; Lower Eocene, Somalia.
• P. migliorinii Checchia-Rispoli, 1941; Lower Eocene, Somalia.

Spatangoida, Micrasterina, Macropneustidae.

?

Thebaster supposedly differs from this taxon in being more depressed and in having a broad and elongately transverse periproct. However, the type specimen is badly crushed and these are artefacts. As Roman & Struogo (1994) show, Thebaster is an objective synonym of Fourtaunia, and the only difference separating Fourtaunia and Pharaonaster is whether a subanal fasciole is present or not (often difficult to tell due to the state of preservation of the material). It further differs from Fourtaunia in lacking enlarged tubercles inside the peripetalous fasciole.

Kier, P. M. 1957. Tertiary Echinoidea from British Somaliland. Journal of Paleontology, 31 pp. 839-902.

Roman, J. & Struogo, A. 1994. Echinoides du Libyen (Eocene inferieur) d'Egypt. Revue de Paleobiologie 13, 29-57.