The sea lilies and their relatives the feather stars are echinoderms (spiny-skinned animals) that have survived for 500 million years with hardly any changes. They give us a glimpse of what life was like in the ancient Cambrian seas.
Sea lilies and feather stars belong to the same family of spiny-skinned animals as starfish, sea urchins, and sea cucumbers. The body of an adult sea lily is attached to the deep ocean floor by a stalk. Feather stars usually live in shallower water. They are only attached to the ocean floor when they are growing; when they become 