Thursday, September 18, 2014

Longispina lissohybus Brachiopod from the Silca Shale

I have found one specimen that I can ID as belonging to the Genus Longispina and that specimen was found in the Mahantango formation. Below is a specimen I purchased as part of a lot from E-bay that comes from the Silica Shale in Paulding, OH. The label indicates that it is Longispina lissohybus but the shell is missing the tell tale spines that normally extend from the hinge line on the left and right sides. The radial ribs that decorate the surface are a bit muted as well so I'm not sure if this really is L. lissohybus. Interestingly, there appears to be a predatory gastropod boring on the pedicle valve.

Pedicle valve
Anterior
Posterior
Profile


The Silica Shale is Devonian (Givetian stage) in age.

Tuesday, September 16, 2014

Devonochonetes scitulus brachiopod from the Silica Shale

I'm pleased to have an example of Devonochonetes scitulus from the Silica Shale near Sylvania, OH. This is a somewhat common brachiopod in the Givetian stage of the Devonian and I've found it in several units across the US.

Pedicle valve
Anterior
Brachial valve
Posterior
Profile

Here are some other examples of this species from the Arkona and Widder Formations at Arkona, Canada, the Mahantango Formation of Pennsylvania and a specimen from Germany that looks very similar.

Sunday, September 14, 2014

Devonochonetes fragilis brachiopod from the Silica Shale

As comparison to the previous Devonochonetes coronatus, here is Devonochonetes fragilis from the Silica Shale (Devonian, Givetian stage) of Sylvania, OH. The difference between this species and D. coronatus appears to be the number and thickness of the rays that extend from the hinge line. At least this is what I can discern from just a visual perspective since they are both about the same size and shape.

Pedicle valve
Anterior
Brachial valve
Posterior
Profile

Friday, September 12, 2014

Devonochonetes coronatus Brachiopod from the Silica Shale

Devonochonetes coronatus is a species that I know well from Givetian aged deposits in Pennsylvania and New York. Below is a specimen from the Silica Shale (Devonian, Givetian stage) near Sylvania, OH. It follows the form that I have used in the past to ID similar shells: Large size, rectangular shape, 1 valve covex while the other is concave. The specimen below has partially been replaced with Pyrite (darker areas) which is why it has a mottled appearance.

Pedicle valve
Anterior
Brachial valve
Posterior
Profile

Compare this to specimens I've found in the Centerfield mbr. of the Ludlowville Formation of New York and the Mahantango Formation of Pennsylvania.

Wednesday, September 10, 2014

Mucrospirifer prolificus brachiopod from the Silica Shale

After M. mucronatus, the next most common species of Mucrospifier in the Silica Shale (Devonian, Givetian stage) is M. prolificus. It has a somewhat ornate shell exterior like M. mucronatus but the interarea is wider (because the beak of the pedicle valve doesn't curl quite as much). The specimen below comes from Sylvania, OH.






Compare this specimen to M. thedfordensis and M. arkonensis from Arkona, Canada, and Eleutherokomma diluvianoides from Poland