clypeasteroid
English edit
Noun edit
clypeasteroid (plural clypeasteroids)
- Any echinoderm of the order Clypeasteroida of sand dollars.
- 2006, Robert Wynn Jones, Applied Palaeontology[1], page 181:
- Their living representatives include the sea urchins or 'true' echinoids, the heart-urchins or spatangoids and allied forms, the sand-dollars or clypeasteroids, and the slate-pencil-urchins, or cidaroids.
- 2008, Anis Kumar Ray, Fossils in Earth Sciences[2], page 217:
- At ordinal levels, in cassiduloids and holectypoids, ambitus is circular, elliptical or oval, while clypeasteroids have a pentagonal to circular type.
- 2009, Andrew B. Smith, “Sea urchins (Echinoidea)”, in S. Blair Hedges, Sudhir Kumar, editors, The Timetree of Life, page 302:
- Their traditional taxonomy, based on skeletal characters, has been largely corroborated by recent molecular phylogenetic analyses with one marked exception: clypeasteroids are not found to be monophyletic.
Synonyms edit
- (any species of Clypeasteroida): pansy shell, sand dollar, sea cookie, snapper biscuit
Hyponyms edit
- (species of Clypeasteroida): sea biscuit