Crinoid "Feather Stars" Columnal Segments

Sometimes referred to as feather stars or sea lilies, Crinoids are members of an extended and very ancient family of sea animals known as echinoderms. Echinoderms date back as far as the Cambrian period some 541,000,000 years ago. They include such varied animals as sea urchins, sea cucumbers, and starfish. Their development was part of a much larger explosion of complex life on Earth which resulted in most of the animal or metazoan body plans we know today.