What are Crinoids?
Q: What are Crinoids?
A: Crinoids are a class of Echinoderms.
Q: What are the two forms of Crinoids?
A: The two forms of Crinoids are sea lilies, stalked forms attached to the sea floor, and feather stars, which are free-living.
Q: Where do Crinoids live?
A: All Crinoids are marine, and they live both in shallow water and in depths as great as 6000 meters.
Q: What is the basic echinoderm pattern?
A: The basic echinoderm pattern is fivefold symmetry.
Q: Do all Crinoids have five arms?
A: No, most Crinoids have many more than five arms.
Q: Where is the mouth of Crinoids located?
A: The mouth of Crinoids is on the top surface and is surrounded by feeding arms.
Q: What is the history of Crinoids?
A: Crinoids have a long history. They were the first echinoderms to appear in the fossil record and have kept their early structure throughout their long career. They were extremely common in the Palaeozoic, and some rocks from the Carboniferous consist almost entirely of fossil crinoids.
