echinoderm

Etymology

From French échinoderme, corresponding to echino- + -derm, after plural of 18th-century Latin echinoderma.

noun

1. An animal of the phylum Echinodermata, comprising radially symmetric, spiny-skinned marine animals including seastars, sea urchins, sea cucumbers, crinoids, and sand dollars.
   Comparatively few additions were therefore made to the previously known Echinoderm-fauna of Brazil, only a single species, a Leptasterias, being with certainty new to science. 1879, Richard Rathbun, A List of the Brazilian Echinoderms: With Notes on Their Distribution, Etc
   Many echinoderms are still bilateral as larvae, and swim freely in the ocean like baby fish. 2012, Caspar Henderson, The Book of Barely Imagined Beings, Granta Books, published 2013, page 47