What kind of fossils are in Lake Michigan?

Answer 1

I have found crinoids (generally the discs from the stalks, either individually or several in a row like a pack of smarties candies), brachiopods (clams), gastropods (snails), cepholopods (similar to squids), and several types of coral (chain coral, honeycomb coral, horn coral) in Lake Michigan. I also found a few that appear to be some type of sponge. Additionally I found several that appear to be some kind of plant or animal skin, although I have not been able to identify them...they aren't in any of the books I've looked at. These were all found on the shore of the southwestern portion of the lake (near Milwaukee). Some rocks on the shoreline have many fossils in them. Most of the fossils are small; anywhere from 1/8 of an inch to a few inches. I'm sure there are other types of fossils in Lake Michigan, but these are what I've found over the past couple years. From what I've found, most Lake Michigan fossils will likely be from the Devonian and Silurian periods...about 350 million to 450 million years ago (that is, of course, supposing science is correct on these timeframes).