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

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

This at least is the conclusion of a landmark recent paper in the journal Nature, which solved a lingering puzzle about starfish anatomy by turning to the enigmatic echinoderm's genes.

From Salon

“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

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

For Martindale, Scucchia, and colleagues, the next step will be to add coral proteins one by one to anemones to try to get them to create actual calcium carbonate crystals—and possibly the minerals of other animals, such as those in echinoderm spines or mammalian tooth enamel.

From Science Magazine