clypeasteroid

English

A clypeasteroid, Mellita quinquiesperforata

Noun

clypeasteroid (plural clypeasteroids)

1. 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

• (any species of Clypeasteroida): pansy shell, sand dollar, sea cookie, snapper biscuit

Hyponyms

• (species of Clypeasteroida): sea biscuit