Crinoids, often referred to as "sea lilies" or "feather stars," are marine animals belonging to the class Echinodermata. They have a unique appearance, resembling flowers with long, feathery arms that extend from a central stalk. Crinoids are primarily found in deep-sea environments, although some species inhabit shallow waters. They feed on small particles in the water, using their arms to capture food. These creatures have a long evolutionary history, dating back to the Cambrian period over 500 million years ago. Crinoids are important to marine ecosystems, serving as both prey and habitat for various marine organisms. Their fossilized remains are commonly found in sedimentary rocks, providing valuable insights into ancient marine environments.