Graptolites

All the pictures in this post are from the same plate.  The first two are of the top and bottom of that plate.  Fossils shown on the plate appear to be graptolites (colonial Paleozoic plankton).  These were found in the Kope Formation of Carroll County, Kentucky dated to the Ordovician Period.

The Fossils of Ohio book list a number of graptolite species found in the Kope Formation: Dicellograptus flexuosus, Dicranograptus nicholsoni, Climacograptus spiniferus, Geniculograptus typicalis typicalis, Geniculograptus pygmaeus, and Orthograptus quadrimucronatus.

Learn more, read Chapter 19 Phylum Hemichordata, Class Graptolithina by Stig M. Bergström in Fossils of Ohio (1996), pp.270-281.

Coalified Callixylon Wood

Devonian wood piece probably from a Callixylon log. A little different that what I normally find. It appears to have diamond shaped patterns that might represent the outer surface. They were found in New Albany Shale in Clark County, Indiana. The wood has been coalified or vitrinized by heat and pressure over time.  This fossil appears to be from the Upper Devonian Period.

This image of the specimen viewed with a microscope shows on the left pyrite mixed with the shale and a small coalified fragment showing on the right.

Fossilized Callixylon Wood

A magnified (400x) view of a sliver of Upper Devonian Period fossilized wood.  It is probably Callixylon found in the New Albany Shale of Clark County, Indiana.  While this area was a sea with anaerobic bottom, it is thought logs floated in from Pennsylvania or New York and sank.  Buried in the silt they fossilized instead of decomposing.


While trying to get a sample for the scanning electron microscope some very small thin pieces broke free.  They were transparent enough to use the optical microscope's bottom light thus able to achieve 400x magnification.  How to determine what material is represented by that optical pattern I am not sure.  I assume it is a fragment of two wood rays.

Last picture original fossil fragment originated from.  This piece differs from yesterday's fossil in that it is not coalified.

Thanks to Herb for the specimen.