Paleozoic Cephalopod Fossil

This fossil is quite a rare find. A coiled cephalopod found it Clark County, Indiana which means it is probably either Silurian, Devonian or Mississippian in age. The label is not too specific. I would guess it is maybe 20 cm across in size.

It is on display at the Indiana University Southeast geology department as of August 2013. It was donated to them by John T. Shelton.

Coiled Nautiloid Fossil Imprint

Over the Thanksgiving holiday I received an image of a fossil imprint of some sort of coiled nautiloid. It was found on the Indiana side of the Ohio River in the Louisville, Kentucky area. The only fossils I know of like that are found in the Louisville Limestone of Silurian Period. If it is a Silurian fossil it might be a Graftonoceras graftonense?. Other Silurian cephalopods found in the area are the Lituites marshi? shown an earlier posting and the Bickmorites shown here.

Thanks to Dana for the images.