Tuesday, September 22, 2009

Brevispirifer gregarius

While at the Falls of the Ohio State Park over the weekend I went on a special hike that they only do when the dam spillway is closed off letting the fossils beds to be exposed more than normal. It is an a fun and long (about 3 hours) hike that can at times be precarious. One gets to walk across the mossy spillway and along a narrow concrete ledge to falls section of the park.

This picture is of a brachiopod that marks zones in the limestone layers. It is called the Brevispirifer gregarius (Clapp, 1857).  It existed in the Jeffersonville Limestone during the Middle Devonian Period. The dark areas of the rock are from volcanic ash falls (metabentonites). I think this one might have been called Kawkawlin which I assume was the name of the volcano.

When I went on this hike one thing I was going to make sure of was to find this brachiopod since it is mentioned is so much literature describing the Falls of the Ohio near Louisville, Kentucky.

You can see another Brevispirifer brachiopod imprint next to this gastropod shell that has crystallized. It is a turrentiform called Palaeozygopleura hamiltoniea.

This last picture of a Great Egret (Casmerodius albus) that was almost driven to extinction because their beautiful white feathers were used in hats.