The Echinoid Directory

Eobrissus Bell, 1904, p. 236

[=Radiobrissus Fourtau, 1913, p. 66, type species R. gneffensis Fourtau, 1913 ]

Diagnostic Features
  • Test ovate withouta frontal groove.
  • Apical disc ethmolytic, with 4 gonopores.
  • Anterior ambulacrum narrow and very slightly sunken; pore-pairs small, simple isopores.
  • Other ambulacra petaloid; petals narrow and sunken, the anterior pair flexed anteriorly. Petals subequal in length. Occluded plates at tips of petals.
  • Periproct large, on short vertical truncate face; bound orally by plates 5.a.5, 5.b.5.
  • Peristome wider than long; kidney-shaped; facing downwards.
  • Labral plate short and wide; not extending beyond ambulacral plate 1.
  • Sternal plates long and parallel-sided; episternal plates forming a significant part of the plastron.
  • Periplastronal zones narrow, weakly bowed.
  • Spines and tubercles within peripetalous fasciole often sightly larger, especially adapically, but tubercles not sunken.
  • Well-developed subanal fasciole and peripetalous faciole. Subanal fasciole shield-shaped and with anal branches. Peripetalous fasciole indented behind anterior petals and in anterior interambulacra.
Miocene to Recent; Egypt, Indian Ocean.
Name gender masculine
Eobrissus townsendi Bell, 1904, p. 236, by original designation.
Species Included
Classification and/or Status

Spatangoida, Micrasterina, Brissidae.

Subjective junior synonym of Metalia Gray, 1855.


Differs from the type species of Metalia in lacking a distinct frontal groove. Mortensen (1951) considered this difference trivial and treated Eobrissus as a junior synonym of Metalia.

Bell, F. J. 1904. Description of a new genus of spatangid. Annals and Magazine of Natural History (series 7) 13, 236-237.

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