This "sea lily" is actually an animal most closely related to starfish, sea urchins and brittle stars.
Like other members of their phylum, crinoids have tube feet, a water vascular system, radial symmetry and appendages in multiples of five. They have a segmented stem, a calyx where the body is and digestion happen, and the arms where they filter food from the environment.
The earliest known crinoids appeared over 480 million years ago and there are still species alive today. Most species attached themselves to the sea floor, but some are known to have been free-swimming.
This specimen displays the cup-shaped calyx and appendages.
Species: Eretmocrinus tentor
Age: Mississippian (358-323 million years ago)
Formation: Gilmore City Formation
Locality: Gilmore City, Iowa
Size of Specimen: 2 x 1.88 x .88 inches
Weight: 1.25 oz.