The Echinoid Directory

Radiobrissus Fourtau, 1913, p. 66

Diagnostic Features
  • Test ovate without anterior sulcus; posterior face truncate. Test depressed in profile.
  • Apical disc ethmolytic with four gonopores; a little anterior of centre.
  • Anterior ambulacrum flush, narrow; pore-pairs small and undifferentiated.
  • Paired ambulacra petaloid; long, parallel, with narrow interporal zone; weakly depressed. Pore-pairs conjugate.
  • In the anterior petals pore-pairs in the anterior column become rudimentary adapically.
  • Peristome D-shaped apparently with labral plate raised to rear.
  • Plastron plating not known for certain; fully tuberculate and apparently rather wide.
  • Periproct on posterior truncate face.
  • Subanal fasciole present; shield-shaped.
  • Peripetalous fasciole narrow; not indented behind anterior petals; ambital around anterior.
  • Aboral tuberculation coarse and heterogeneous inside peripetalous fasciole.
Miocene (Vindobonian), Gebel Geneffe, Egypt.
Name gender masculine
Radiobrissus gneffensis Fourtau, 1913, p. 66, by original designation.
Species Included
  • Only the type species.
Classification and/or Status

Spatangoida, Micrasterina, Brissidae.

Monotypic; subjective junior synonym of Metalia (Eobrissus) Bell,1904

Differs from Trachypatagus in having a shield-shaped subanal fasciole, not a bilobed one, and from Metalia by having non-confluent posterior petals. Metaliopsis has a sunken anterior ambulacrum and does not have the anterior atrophied pore-pairs in the anterior petals