Carbonaceous Filmed Pelecypod Fossil

This interesting fossil is some sort of clam preserved by carbonaceous film. It was found in the Lexington Limestone of Franklin County, Kentucky. The name might be a Psiloconcha sp.  If you look at the picture of the matrix plate, it was fossilized in place with a number of other sea creatures. In addition, a brachiopod imprint appears in the matrix as well. Also the clam might have some calcite crystals at one end of it.

Thanks to Lawrence for these fossils.

Coiled Crinoid Holdfast/Arm

At first glance, this fossil looks like a coiled up millipede or some sort of worm. This coiled crinoid holdfast was probably used by the creature to anchor itself on the seafloor so it would not float away. It was found near railroad tracks in Indianapolis, Indiana. If I had to guess, it is probably from the Mississippian Period.

Thanks to Daniel for sharing this picture.

Syringopora monroenae? Coral

This larger colonial coral fossil specimen was found in Hardin County, Kentucky. It is Mississippian in age and might be from the Salem Limestone. It appears to match the characteristics of a Syringopora monroenae coral fossil.

Thanks to Kenny for loaning me the fossil to photograph.

The last two pictures are from the Indiana Department of Geology and Natural Resources Thirtieth Annual Report, W.S. Blatchely State Geologist, 1905. They are Figures 1 and 2 in Plate X on pages 1402-1403. Listed as a specimen in the Indiana University collection.

Plate X Figure 1 page 1403

Plate X Figure 2 page 1403