Have you ever gone on a scavenger hunt? On these hunts, you look for specific things. This week I’ve been on a scavenger hunt for fossils along the shores of Lake Superior in Michigan. My family has found these fossils on previous trips to Michigan and the Great Lakes area. This trip, I’ve been keeping my eye out while walking along beaches and snorkeling in chilly waters. Yesterday I came across one rock with small crinoid fossils—but what exactly is a crinoid?
Crinoids are also called sea lilies because they look like flowers; but they are not plants—they are animals. Crinoids are echinoderms: the same phylum (large category) of animals as sea stars.
Crinoids are alive today in oceans around the world. Some live at depths of around 30,000 feet. Some types of crinoids have a tall stalk, resembling a flower stem, and sway in groups on the ocean flower—like wildflowers swaying in a breezy meadow. But remember: crinoids are animals! Their beautiful, feathery arms catch tiny plants, animals, and ocean debris that drift past for them to eat.
Many crinoids were rapidly buried in the worldwide flood, which is why we can find many fossils of them today. Michigan is a great place to look for these treasures. Their fossils can resemble threaded screws. You might find long fossils with grooves, or a single ring. Some have star-shaped stems that break apart and create fossilized stars.