urchin
urchin, any of several marine invertebrates of the class Echinoidea (phylum Echinodermata), including the cake urchin, heart urchin, and sea urchin (qq.v.).
This article was most recently revised and updated by Amy Tikkanen.
Citation Information
Article Title:
urchin
Website Name:
Encyclopaedia Britannica
Publisher:
Encyclopaedia Britannica, Inc.
Date Published:
11 March 2026
Access Date:
November 14, 2026