The Echinoid Directory

Phymapatagus Lambert, 1910, p. 3

Diagnostic Features
  • Test cordate with shallow anterior sulcus; domed upper surface and rounded ambitus with relatively flat base.
  • Apical disc ethmolytic, with 4 gonopores. Madreporic plate extends to rear of apical disc where it widens.
  • Anterior ambulacrum narrow with small, simple isopores (i.e. no funnel-building tube-feet). Other ambulacra petaloid and flush.
  • Anterior paired petals bowed with upper half of anterior column with rudimentary pore-pairs only. Other pore-pairs large and conjugate. Posterior petals bowed and converging distally.
  • Periproct on short steeply undercut posterior face.
  • Peristome wider than long; kidney-shaped, with weakly projecting labrum.
  • Labral plate apparently longer than wide but not extending much beyond first ambulacral plate; in broad contact with sternal plates; paired sternal plates relatively broad and fully tuberculate.
  • Plastron formed of sternals and episternals; plate arrangement unknown.
  • Aboral tuberculation heterogenous with scattered coarse tubercules in all but the posterior interambulacrum. Primary tubercles not sunken in camellae. Somewhat smaller tubercles developed along either side of the frontal groove aborally and along the interradial line behind the apical disc.
  • Well-developed subanal fasciole; bilobed or shield-shaped; no other fascioles.
Eocene to Miocene, Europe.
Name gender masculine
Spatangus britannus Michelin, 1868, p. 382, by original designation.
Species Included
  • The type species comes from, the Miocene of Brittany, France. Lambert & Thiery (1921) included 3 other species, P. grignonensis (Desmarest), P. heberti (Cotteau) and P. koeneni (Ebert), none of which have been examined.
Classification and/or Status

Spatangoida, Micrasterina, Spatangidae.

Subjective junior synonym of Spatangus Gray, 1825.


Originally distinguished from Spatangus by lacking primary tubercles in the posterior interambulacrum aborally, and from Hemipatagus by having a fully tuberculate plastron.

Lambert, J. 1910. Addition a l'etude des echinides dea falune. Note sur deux echinides des faluns de Touraine. Feuille Jeunes naturalistes (5), 40, no. 481, p. 2-6, 1 pl.

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