from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun An echinoderm of the class Echinoidea, which includes the sand dollars and sea urchins.

from The Century Dictionary.

  • Having the form or appearance of a sea-urchin: in entomology, applied to certain insect-eggs which are shaped like an echinus, and covered with crowded deep pits.
  • Pertaining to the Echinoidea.
  • noun In zoology, one of the Echinoidea.

from the GNU version of the Collaborative International Dictionary of English.

  • adjective (Zoöl.) Of or pertaining to the Echinoidea.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun zoology Any sea urchin or sea dollar of the class Echinoidea


Sorry, no etymologies found.


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  • An unidentified holothurian is common on the northern reef flats, and an echinoid Heterocentrotus sp. (possibly H. trigonarius) is locally abundant on the sloping marginal reefs and shallow reef flat of the northern beach.

    Henderson Island, United Kingdom 2008

  • Minokawa T, Amemiya S (1999) Timing of the potential of micromere-descendants in echinoid embryos to induce endoderm differentiation of mesomere-descendants.

    PLoS Biology: New Articles 2009

  • Gao F, Davidson EH (2008) Transfer of a large gene regulatory apparatus to a new developmental address in echinoid evolution.

    PLoS Biology: New Articles 2009


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