Trilobite cephalon found in the Waldron Shale.  Middle Silurian Period was the age this creature lived.   It appears to be a Glyptambon v...

The Smithsonian Museum of Natural History of Washington D.C. has an extensive collection of Ohio trilobites on display.  It consists...

Paradichocrinus planus crinoid calyx found in Indiana.  It existed in the early Carboniferous Period (345-325 million years ago).  Pictur...