To honor National Fossil Day I thought I’d show a photo of the official state fossil, Isotelus. This huge trilobite was named as the state fossil in 1985, after lobbying by two Dayton, Ohio area elementary schools. The original fossil was found at Huffman Dam near Dayton in 1919. At 14 1/2 inches long, this is one of the largest complete trilobites ever found! The Ordovician rocks exposed in southwest Ohio are known worldwide for their abundance of invertebrate fossils, especially trilobites. This specimen is at the Smithsonian, but there is a beautiful 9 1/2 inch specimen on exhibit at the Ohio Historical Center.
For more information go to GeoFacts published by the Ohio Geological Survey: http://www.dnr.state.oh.us/Portals/10/pdf/GeoFacts/geof06.pdf