Cryptolithus Glabella

The Kope Formation of  Carroll County, Kentucky produces a lot of Cryptolithus tessellatus fragments.  This Ordovician Period trilobite was thought to be blind.  Today's post is to highlight a part of the trilobite rarely found in this collecting location: the glabella.  The center tear drop shape usually wears away from these probably molts.  This shape can be seen in the first picture in the top left corner centered in the lace collar area.

The green arrows point to possible Cryptolithus glabellas in this rock plate.  The red arrow points to pygidium of maybe a Flexicalymene.

Next picture shows the plate with a ruler to give one an idea of its size.

Thanks to Kenny for letting me use his air abrasion cleaning system to reveal more details of these trilobite fragments.

Dictyonema Graptolite

Dictyonema sp. graptolite fossil found in the Waldron Shale of Clark County, Indiana.  Fossil is from the Silurian Period.

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.