Crinoids look like plants and are also called “sea lilies,” but crinoids are in fact invertebrate marine animals of the phylum Echinodermata. They are related to starfish and sea urchins. Direct ancestors of the fossilized crinoids survive today, but these simple creatures reached their peak in the Mississippian Period, which is sometimes known as the “Age of Crinoids.” Although there were many species of crinoids, they shared a basic morphology consisting of a stem by which it anchored to the sea floor, a calyx which enclosed soft body tissues, and arms which filtered food from the water. These were once abundant in ancient seas, but are still found in modern day in certain locales. They somewhat resemble a small underwater palm tree.
Crinoids were passive feeders that collect food particles as current-driven water passes over their feathery arms. Multiple species of crinoids lived together in dense communities. Species often differed in the length of their stem and the configuration of their calyx and arms, and thus could live in the same space but occupy different niches in the water column.
It is the columnal section of the crinoids that are found fossilised in this area. Below are some images of what you are looking for. It is easiest to find these when the rock is wet as the contrasted colors make them much easier to spot. You may be lucky enough to find a small rock containing them, but most are more suitable for collecting via photographs than physical collection.
Some pictures I took:
This piece of land that stretches out into the Bay is man-made, necessary to support and maintain the ecological life in the area. The rocks used here are of varying types including limestone, and came from the Niagara Escarpment. During the Ordovician period, the Michigan Basin was under a shallow, tropical sea. Muds and sands were deposited from erosion of the Taconic Mountains to the south, creating the base shale and sandstone units of the Niagara Escarpment. Later, during Silurian period, the Taconic Mountains stopped uplifting, erosion slowed, and calcium carbonate sediments formed, creating the upper limestone and dolostone layers of the Escarpment. Fossils such as sponges, crinoids, brachiopods and rugose corals, indicating warm tropical waters, can be found in the Escarpment.
To Log This Earthcache:
1. Other than the columnal section of the crinoid, did you observe any other sections?
2. Using a metal object (keys, coin, knife etc.) make a scratch on one of the fossil bearing rocks. What did you scratch it with? Does it leave a streak and if so what color?
3. What are the average sizes of the crinoids fossils you see in the stone?
4. Post a picture of you, and/or your GPS with one of the crinoids (Optional).
Please send me these answers in an email. All found it logs that are not accompanied by an email will be deleted.