crinoids

Crinoids are marine animals related to sea stars and sea urchins, known for their feather-like arms that extend from a central body, resembling underwater flowers. They use these arms to filter food particles from the water, such as plankton. Crinoids have a hard, calcareous skeleton and can be attached to the seabed with stalks or free-swimming. They existed hundreds of millions of years ago, thriving in various ocean environments, and many fossils of crinoids help scientists understand Earth's ancient marine life. Despite their ancient origins, some modern crinoid species still inhabit deep and shallow waters today.