In honor of this upcoming holiday, I will write today about one of my favorite fossils. Yes folks, it is the Ohio state fossil Isotelus. First, what isn't there to love about a large trilobite? Second, the history of Isotelus in Ohio goes back a long way.
Isotelus specimens from Ohio were first described by John Locke in the late 1830s under the guise of the first Geological Survey of Ohio. Much of southwestern Ohio is underlain by Late Ordovician rocks. These rocks were deposited as part of a shallow epicontinental sea. They are full of fossils of brachiopods, bryozoans, bivalves, gastropods, trilobites, and many other critters. These rocks are now exposed in streambeds and roadcuts around Cincinnati and the surrounding area.
|Huffman Dam Isotelus|
*Much of this information comes from the Ohio DNR's GeoFacts #6, available here.