Crinoids or sea lilies are a member of the phylum Echinodermata, a group that also includes sea cucumbers, sea urchins, sea stars, and brittle stars. Most crinoids live on the bottom of the ocean where they filter the water for plankton and other particles to eat, whereas others swim in search for food. They are commonly found in Mississippian rocks in northern Alabama. As crinoids are also abundant in marine rocks elsewhere during the Mississippian, this subperiod is often referred [...]
