echinoderm

[ ih-kahy-nuh-durm, ek-uh-nuh- ]

noun

1. any marine animal of the invertebrate phylum Echinodermata, having a radiating arrangement of parts and a body wall stiffened by calcareous pieces that may protrude as spines and including the starfishes, sea urchins, sea cucumbers, etc.

echinoderm

/ ɪˈkaɪnəʊˌdɜːm /

noun

1. any of the marine invertebrate animals constituting the phylum Echinodermata, characterized by tube feet, a calcite body-covering (test), and a five-part symmetrical body. The group includes the starfish, sea urchins, and sea cucumbers

echinoderm

/ ĭ-kī′nə-dûrm′ /

1. Any of various marine invertebrates of the phylum Echinodermata, having a latticelike internal skeleton composed of calcite and usually a hard, spiny outer covering. The body plans of adult echinoderms show radial symmetry, typically in the pattern of a five-pointed star, while the larvae show bilateral symmetry. Echinoderms probably share a common ancestor with the hemichordates and chordates, and were already quite diversified by the Cambrian Era. They include the starfish, sea urchins, sand dollars, holothurians (sea cucumbers), and crinoids, as well as thousands of extinct forms.

Derived Forms

• eˌchinoˈdermal, adjective

Word History and Origins

Origin of echinoderm¹

1825–35; taken as singular of New Latin Echinodermata, neuter plural of echinodermatus < Greek echîn ( os ) sea urchin + -o- -o- + -dermatos -dermatous

Example Sentences

It was at first thought that we had before us an echinoderm in the act of transformation.

From Project Gutenberg

He considers the Rotifers to be "the permanent forms of Echinoderm larvæ."

From Project Gutenberg

There seems to be little or no literature on the central nervous system of this form of echinoderm.

From Project Gutenberg

A resemblance to the other Echinoderm larvae is found in the fact that coelomic diverticula of the enteron are present.

From Project Gutenberg

Half a dozen varieties of these are known, one of which inhabits an echinoderm, another a decapod crustacean.

From Project Gutenberg