Crinoids: Living Fossils of the Sea (PA-09)
Crinoids, called sea lilies, are marine echinoderms related to starfish and sand dollars. Though they are animals, they resemble plants. The head (crown) is generally raised on a long stem of platelike discs fastened to the sea floor by a stony, rootlike anchor. There are about 600 species alive today, most of which lack a stem and can move about.

When crinoids die, the skeleton plates tend to fall apart, so complete crinoid heads are highly prized. Many Indiana limestones contain many crinoid stems and plates, locally called Indian beads. Fossil crinoids were discovered an long before living ones were noticed. These animals are still important marine life, especiallly near the coral reefs and in the deep sea, but they are not nearly so common as they once were.

Our Hoosier State Beneath Us: Paleontology