Crinoids were creatures that looked like flowers on thick stems. They can easily be mistaken for a flower, but they are a marine animal. Small discs, usually round, stacked together to form the stems. The parts of the crinoid that looks like flower petals are its arms. With these arms the crinoid catches its food in the water. Crinoid means "like a lily". During the Mississippian period they covered many parts of the sea bottom, but today only a few kinds are left.