Paleozoic Pelecypods

Hundreds of millions of years ago in the Paleozoic seas of the Ordovician, Silurian, and Devonian periods, brachiopods were the dominate shelled creature of the sea floor. Clams on the other hand just occupied a small area of this habitat. As a result clam fossils are harder to find. In this collector's experience, the ratio is at least 1 to 100 of clam to brachiopod fossils found. In addition, clams tend to just be molds (steinkerns) of the inside of shells or imprints left on limestone.

In the modern world, the fortunes of the brachiopods and clams have reversed with the clams the more dominant animal and brachiopods scarce.

These fossils can be acquired on eBay CLICK LINK HERE (auction ends April 4, 2011)

The Ordovician (468-458 million years ago) clams are just molds of the internal shell they include the Ambonychia and Modiolopsis.

The Silurian period (438-408 million years ago) is represented by Cypricardina arata?. This fossil has some nice contrast with the limestone matrix.

The Devonian period (408-360 million years ago) fossils are Limoptera cancellata?, Paracyclas elliptica, and the Paracyclas lirata?. These fossils show the most promise if cleaned more to reveal further details of the fossil imprint.

Ambonychia Steinkern

Cypricardina arata?

Paracyclas lirata?

Modiolopsis, Limoptera cancellata?, Paracyclas elliptica

COAL - Show Premieres Tonight

Tonight (March 30, 2011) at 10 PM EST, a show premieres on Spike TV called Coal.  It will show the internal workings of the Cobalt Coal Company, its 600 feet deep mine, and the miners who extract coal there.  The mine is located at Westchester Mountain in McDowell County, West Virginia, USA.  The mine obtains its coal from the Sewell Seam.  Coal obtained at the mine is used in the steel making industry with the "metallurgical" grade being used for coke production.

Watching the preview, one gets to see a lot of the internals of the mine and some nice computer graphic sequences showing the mine operations. 

Coal First Look – The First 14 Minutes Of The Series Premiere
Tags: Coal First Look – The First 14 Minutes Of The Series Premiere

A lot of preview videos are available on the Spike TV web site CLICK LINK HERE

Learn more at the Cobalt Coal web site CLICK LINK HERE

Visitors to Louisville, Kentucky can check out an informative coal display at the Louisville Science Center.

Tentaculites with Devonochonetes

Presented for your visual inspection, a Devonian hash plate from the Silver Creek Limestone of Clark County Indiana.  An intact Tentaculites with a lot of Devonochonetes brachiopods.

The Tentaculites is an extinct molluscs that lived in the Devonian and Silurian.  The ringed cone like shell is known as a conch.  Study of Devonian pyrite specimens from Germany alludes to the creature having tentacles.   So maybe they were like miniature shelled squids.  The next image shows the Tentaculites being about 1 cm in length.

Learn more about Tentaculitoids in the 1996 book Fossils of Ohio, Chapter 20 (pp.282-287) written by Stig M. Bergström.

This fossil is available for purchase on eBay CLICK LINK HERE.

On one side of this limestone block, is a cross section of a brachiopod with calcite crystals.

On the bottom of the plate are more remains of brachiopods plus this pygidium of a trilobite.  More that like it belonged to a Phacops.

View of top of plate:

View of bottom of plate:

View of one of the sides: