A heads up for National Fossil Day!

As I'm sure you are all aware, October 13, 2010 marks America's first National Fossil Day! You can learn all about it at the National Parks website. This is a day to celebrate our prehistoric heritage. I'll have a more complete post about this closer to the big day.

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

Two elementary school groups had been to the Dayton Museum of Natural History (now the Boonschoft Museum of Discovery) and seen a cast of one of the largest whole trilobites found in Ohio - the Huffman Dam specimen. The children wrote letters to their representatives and the issue received widespread publicity. On June 20, 1985, Isotelus became the state fossil of Ohio.

*Much of this information comes from the Ohio DNR's  GeoFacts #6, available here.