This rare whole trilobite is called Odontocephalus sp. from the Middle Devonian period. Note the intact forked tail and border around the cephalon. This trilobite is of the suborder Phacopina and the superfamily Dalmanitoidea.
It was found in the Jeffersonville Limestone in the Falls of the Ohio state park, Clarksville, Indiana. Just a note, fossil collecting in the park is prohibited. If it were, there would be no park!
This website has a nice set of pictures of an intact one at the Museum of Natural Science in Houston, Texas. The trilobite seems to be common to area now known as the state of Pennsylvania.
UPDATE (March 2011) - The Falls of the Ohio State Park web site has a nice write up on trilobites with the lead photo being the specimen pictured above. Check it out by CLICKING HERE.
