Geocoma corinata Brittle Star
Anti-Atlas Mountains, Morocco
Ordovician Period (485.4-443.8 million years ago)
Geocoma is an extinct genus of brittle stars that lived in the Jurassic. These are slow-moving low-level epifaunal detritivore-suspension feeders. Brittle stars or ophiuroids are echinoderms in the class Ophiuroidea closely related to starfish. They crawl across the sea floor using their flexible arms for locomotion. The ophiuroids generally have five long, slender, whip-like arms which may reach up to 60 cm (24 in) in length on the largest specimens. They are also known as serpent stars; the New Latin class name Ophiuroidea is derived from the Ancient Greek word meaning "serpent". The Ophiuroidea contain two large clades, Ophiurida (brittle stars) and Euryalida (basket stars). Over 2,000 species of brittle stars live today. More than 1200 of these species are found in deep waters, greater than 200 m deep.