Crinoids: Ancient versus Modern Forms (PA-08)
Modern crinoids (sea lilies or featherstars) are related to starfish. They thrived in ancient seas 200 to 400 million years ago during the Paleozoic Era. Early specimens were attached to the sea floor on stems, though some later forms lack a stem and can crawl about and swim. Fossil crinoids are found abundantly in Indiana limestones, derived from limy muds and sands that accumulated in ancient seas that once covered Indiana.

Crinoids live today in temperate warm seas. Some modern crinoids inhabit the Caribbean Sea from Honduras to Barbados and north to the Bahamas. In the Bahamas area five species are found. They are marked distinctly with bright colors green, black, yellow, orange and gold. Their arms range in number from 10 to 40. Crinoids have the ability to shed an arm and grow two in its place. The Nemaster, the most common crinoid of the West Indies, is found at depths of 25 to 200 feet. Modern crinoids usually hide beneath or among sponges, corals or dense patches of algae.

Our Hoosier State Beneath Us: Paleontology


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