Mystery Devonian Rock

Mystery rock picked up in an area with Jeffersonville Limestone Devonian Period fossils. When I picked up the rock I assumed it was the inside of brachiopod. The inner part has a blue appearance. It reminds me of some of the crinoid stems found at Lake Cumberland, Kentucky. At one time, I thought it might be agate but there are no layer lines. Could it be some sort of blue opaque quartz or blue chalcedony? Then there is the crystal area, that I guess is calcite.

The area surrounding the nodule shape has a lot of dendrite patterns. I did not test the rest of the stone but I assume it is limestone.  Found in Clark County, Indiana.  I only found one half, not sure where the other part is.

What the nodule looks like from the back.

Mucrospirifer mucronatus Brachiopod

Pictures of a sampling of small brachiopods (1.5-3.0 cm wide) found in the Jeffersonville Limestone (Devonian Period). Using the Fossils of Ohio book and Index Fossils of North America this brachiopod is a Mucrospirifer mucronatus. The Ohio book says they are found in the Columbus Limestone which I think is similar to the Jeffersonville Limestone this was found in. Looking at Nettelroth's book Kentucky Fossil Shells (1889) this brachiopod seems to closely match images on Plate XII figures 14-15 of Spirifera arctisegmenta (1889 name) or today's Spirifer arctisegmenta (Hall, 1857).

Another document I have entitled Middle Devonian Type Jeffersonville Limestone at the Falls of the Ohio by James E. Conkin, Barbara Conkin, and Larry Steinrock on page 8, figure 5 labeled Diagnostic fossils of the Jeffersonville Limestone shows it as "Spirifer duodenarius" in the Paraspirifer acuminatus Zone.

So confusing but all the names seem to have spirifer in them.

All brachiopods found in Clark County, Indiana.

Upper Cretaceous Foraminifera

Pictures are of foraminifera fossils from Starksville, Mississippi. Recovered from the Prairie Bluff Formation that contain fossils from the Upper Cretaceous Period. This first fossil might be an Anomalina sp. Images were photographed at 100x with a microscope thus need to be stacked but I am not quite ready to climb that incline.  My images do not show the divots and bumps that appear on the surface of some of these fossils.

I used A Preliminary Report of the Foraminifera of Tennessee by Joseph A. Cushman (1931) as an identification guide (plates 11 and 12).  It contains a number of specimens from the Upper Cretaceous.  Thanks to Herb for the material.  It is fossil rich!

This next fossil I cannot even guess at an identification.

This fossil might be a Globigerina sp.

Last fossil could be a Globigerinella sp.

Index Fossils of North America lists a number of Upper Cretaceous foraminifera that can be found in Mississippi: Palmula (6-14), Frondicularia (6-17), Kyphopyxa (6-18), Guttulina (7-1), Pseudopolymorphina (7-3), Gumbelitria (8-2), Gumbelina (8-1), Rentilabrella (8-4, 8-5), Bolivinoides (8-6), Pseudouvigerina (8-11), Siphogenerinoides (8-12), Buliminella (8-13), Neobulimina (8-16), Loxostoma (8-18), Lamarckina (9-2), Globigerina (11-1), and Globotruncana (11-9).