Ophiocomina nigra, commonly known as the black brittle star or black serpent star, is a species of marine invertebrate in the order Ophiurida. It occurs in the north-eastern Atlantic Ocean, the North Sea, and the Mediterranean Sea.
Ophiocomina nigra
Brittle stars, serpent 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.
Brittle star
Brittle star in Kona, Hawaii
Ophiopetra lithographica from the Lower Hienheim Beds (Lower Tithonian, Upper Jurassic) near Regensburg, Germany
Asteriacites, a trace fossil of an ophiuroid; Carmel Formation (Middle Jurassic), near Gunlock, Utah; scale bar is 10 mm.