Productella spinulicosta - Devonian Spiny Brachiopod

UPDATE: I originally labeled this as a spiny snail but after more research it is a spiny brachiopod.  The descriptions have been now fixed.

Here is a Devonian brachiopod a friend found on his visit to Louisville. It has 5 spines visible and is around 2 cm in diameter. It is sharing rock with several brachiopods and a horn coral.

It appears to be a Productella spinulicosta (Hall, 1867) in the Jeffersonville Limestone.  Might also be known as Spinulicosta spinulicosta (how original).

According to this Kentucky Geological Survey page, the Jeffersonville Limestone is similar to the Onondaga Limestone of New York and the Grand Tower of Illinois (Savage, 1931).

Fossil Hunting on Memorial Day Weekend

I had a fun and educational experience on Sunday visiting with a fellow fossil enthusiast at a local Devonian roadcut. Here is a nice find of a spiny brachiopod. It looks to be a Productella spinulicosta (Hall) in the Jeffersonville Limestone. The partial brachiopod to its left in the picture is some sort of spirifer.

Large coral head embedded in the rock wall.

Large horn coral embedded into the wall.

Maybe a distant relative to the trilobite?

Calcite crystals where once a brachiopod existed?

Turbinopsis shumardi or Pleuronotus decewi

Using the Fossils of Ohio (Bulletin 70: Ohio Division of Geological Survey; 1996) on page 154 in the chapter on Phyllum Mollusca, Class Gastropoda. I normally label the fossil shown in the pictures as Turbinopsis shumardi from the Jeffersonville Limestone.



I believe the Jeffersonville Limestone of Kentucky and Indiana corresponds to the Columbus Limestone in Ohio. The book describes "Pleuronotus decewi is a large, pseudoplanispirally coiled form that has sharp angulations forming the upper and lower margins of the whorls. It is also commonly preserved as an internal mold, which does not show the selenizone. The genus is restricted to the Devonian."

So maybe this snail could be the one described in the book? Ruler units are in centimeters.