echinoderm

American  

[ih-kahy-nuh-durm, ek-uh-nuh-] / ɪˈkaɪ nəˌdɜrm, ˈɛk ə nə- /

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.

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echinoderm British  

/ 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

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echinoderm Scientific  

/ 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.

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Other Word Forms

• echinodermal adjective

Etymology

Origin of echinoderm

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

Example Sentences

The study begins to probe a bigger evolutionary question: How did the sea star and its equally-strange echinoderm siblings develop their unique starlike symmetry?

From Scientific American • Nov. 3, 2023

“It seems the whole echinoderm body plan is roughly equivalent to the head in other groups of animals,” study co-author Jeff Thompson of University of Southampton said in a release from that British school.

From Washington Times • Nov. 2, 2023

When Formery joined Lowe's lab, Formery's knowledge of echinoderm development combined with Lowe's expertise in molecular biology techniques to help tackle the mystery of sea stars' baffling body plan.

From Science Daily • Nov. 1, 2023

And the new learning will go wider still, says echinoderm specialist Jeff Thompson.

From BBC • Jul. 21, 2021

If it is more culpable to kill an ignorant human savage than an elephant, it is also more culpable to kill an elephant than an echinoderm.

From The Minds and Manners of Wild Animals A Book of Personal Observations by Hornaday, William Temple