Friday, April 20, 2012

Micro fossils in the North Evans Limestone

 After photographing the fossil wood from the North Evans Limestone (NEL) I took a closer look with my Zorb microscope/camera. The NEL is composed of fossil fragments that eroded out of Hamilton group and Genesse formation rocks right at the boundary between the middle and upper Devonian epochs. I'd read that fish teeth and bone fragments could be found within it along with conodonts and scolecodonts which are teeth and jaws from soft bodied animals (eel like vertebrates for the former and annelid worms for the latter). Below are pictures of some of what I found. Please note that the area shown in each picture is approximately 9mm across.

These are fragments of bone or placoderm armor that show rounded edges which is a clear indication of tumbling or reworking by waves.

This one is stained by pyrite as it was close to a piece of fossilized wood.

Conodont/Scolecodont teeth

Fish teeth

This last picture is of a shark tooth that is from Wellerodus wellsi.
Special thanks go out to Karl Wilson, who's website New York Paleontology I frequent regularly, for helping me ID this fossil. He sent me a paper by Susan Turner entitled "'DITTODUS' SPECIES OF EASTMAN 1899 AND HUSSAKOF AND BRYANT 1918 (MID TO LATE DEVONIAN)" Modern Geology, 1997, Vol. 21, pp. 87-119. In the paper she condenses some different genera into the single genus of Welleodus.

Karl's website has some pics of the many micro fossils that can be found in the NEL here.