ClipArt ETC
A sea-urchin very similiar to the Sand Dollar, but has 5 "keyholes" through its shell.

Keyhole-Urchin

A sea-urchin very similiar to the Sand Dollar, but has 5 "keyholes" through its shell.

A sea-urchin in the shape of a circle. Has 5 star-like markings on its top-side.

Sand-Dollar

A sea-urchin in the shape of a circle. Has 5 star-like markings on its top-side.

An diagram of the anatomy of a sea urchin. Sea urchins are small, globular, spiny sea creatures, composing most of class Echinoidea. They are found in oceans all over the world. Their shell, or "test", is round and spiny, typically from 3 to 10 cm across. Common colors include black and dull shades of green, olive, brown, purple, and red. They move slowly, feeding mostly on algae. Sea otters, wolf eels, and other predators feed on urchins. Sea urchins are harvested and served as a delicacy.

Sea Urchin

An diagram of the anatomy of a sea urchin. Sea urchins are small, globular, spiny sea creatures, composing…

Sea urchins are small, globular, spiny sea creatures, composing most of class Echinoidea. They are found in oceans all over the world. Their shell, or "test", is round and spiny, typically from 3 to 10 cm across. Common colors include black and dull shades of green, olive, brown, purple, and red. They move slowly, feeding mostly on algae. Sea otters, wolf eels, and other predators feed on urchins. Sea urchins are harvested and served as a delicacy.

Sea Urchin

Sea urchins are small, globular, spiny sea creatures, composing most of class Echinoidea. They are found…

An illustration of various sea urchin fossils. "1, Palaeechinus; Carboniferous; 2, A plate and radiole of Archaeolcidaris; 3, A radiole of Cidaris; Jurassic; 4, Hemicidaris; Mid. Jurassic; 5, Salenia; Cretaceous; 6, Dyaster; Jurassic; 7, Enallaster; Cretaceous; 8, Catopygus; Cretaceous." -Britannica, 1910

Sea Urchin Fossils

An illustration of various sea urchin fossils. "1, Palaeechinus; Carboniferous; 2, A plate and radiole…

The shell of a sea-urchin without spines.

Sea-Urchin

The shell of a sea-urchin without spines.

Under surface of a Sea Urchin showing rows of suckers among the spines.

Under side of a Sea-Urchin

Under surface of a Sea Urchin showing rows of suckers among the spines.

Phormosoma luculentum is a species of Sea Urchin in the class Echinoidea.

Sea Urchin

Phormosoma luculentum is a species of Sea Urchin in the class Echinoidea.