A late Cretaceous Period (about 112 million years ago) fossil tooth of the Protolamna sokolovi shark. This fossil is from the rare Lamnid...

The distinctive ribbed coiled ammonite is known as the Mortoniceras sp. found in Tarrant County, Texas. It was found in Duck Creek Formati...

This entry shows a number of Ordovician Period bryozoan holdfasts. They were found in Franklin County, Kentucky in the Lexington Limestone....