Dipleura dekayi trilobite from the Panther Mountain formation

At the borrow pit near Cole Hill, NY parts of the trilobite Dipleura dekayi are fairly common. Isolated Cephalons and Pygidiums are most common but occasionally whole specimens can be found. Here is a large piece of mudstone with a well preserved Dipleura cephalon. It is half buried in the rock still but the upturned "scoop" like part is intact. I have yet to find a specimen, either whole or as an isolated cephalon, with the eyes intact. They rise up on short stalks and break off easily when the rock splits. Note all the tiny dots or stippling that can be seen all over the cephalon fossil. These are thought to be sensory pits or had some kind of hair like projection coming out of them. Maybe they helped it sense prey as it burrowed through the sediment.

This is an isolated pygidium that shows the same stippled features.

I also found this little enrolled specimen although he is not in the best of shape.

The rocks at Cole Hill are part of the Panther Mountain Formation which are Devonian in age (Givetian stage).

Evidence of post mortem activity in fossil Pelecypod shells from the Panther Mountain formation

Once a hard shelled animal dies it's shell often lies around on top of the muddy bottom until it gets buried. While it is exposed it provides a hard surface for many other encrusting animals that otherwise would not be able to establish themselves. Today I have two examples of trace fossils that were left on the interior surfaces of pelecypod shells from the Devonian aged Panther Mountain formation in NY.

First up is this shell which may be an Actinodesma erectum or another species. It's hard to say for sure because along the hingeline only the wing is visible and not the ear. But that is not why I kept the piece. What caught my eye are the spider like trails that criss cross the fossil.

It's important to remember that the fossil is not composed of shell material (actual, remineralized or replace). Instead it is a cast that shows the interior surface of the shell. If it were a mold the shell would be concave and not convex like this specimen.  Getting back to the fossil, a closer look reveals what looks like cracks in the surface (which was my initial reaction). I think there is a better explanation though. These lines all join together and are sinuous in places and they also have differences in depth and width. Perhaps they are evidence of worm tubes or bryozoans that colonized the interior surface of the shell while it was exposed. It could also be evidence of a type of sponge that bored into shells and used the calcium carbonate to build it's skeleton.

 Then, off to the left side, I noticed another pattern. This one looks like a bursting firework or a flower like a Dahlia.

 A closer view shows a clear pattern and I think it is of a species of bryozoan called Paleschara incrustans. Interestingly, it appears to have over grown over one of the sinuous lines implying it colonized the shell later before it ultimately became buried.

 Another pelecypod fossil from the same locality is shown below and this one has multiple, straight and wide traces on it. 

To me these look very much like a boring clam or sponge that was digging a home within the shell of the expired clam.

Both specimens come from the Panther Mountain formation (Devonian, Givetian stage) at Cole Hill Rd. quarry in Madison county, NY.

Camarotoechia sappho brachiopod from the Panther Mountain formation

I found this Camarotoechia sappho brachiopod at the Cole Hill Rd. locality in Madison County, NY. It comes from the Panther Mountain formation (Devonian, Givetian stage). I kept this specimen because it is a nice internal mold of the species whereas many of the other available specimens were just impressions in the rock and clustered tightly together. It's not perfect, however, there is a chip missing off the posterior that took the beak with it. Still it gives me a good representative specimen from the locality until I come across something better.

Actinodesma erectum pelecypod from the Panther Mountain formation

This large steinkern, or cast, fossil is a pelecypod that I found at the Cole Hill locality in Madison County, NY. I've been reviewing some resources like "The Paleontology of New York" (James Hall, 1884) and "A field Guide to the Devonian Fossils of New York" (Karl Wilson, 2014) and I think that this fossil is of a Actinodesma erectum. It's a large, oval shaped steinkern with the body vertically aligned (or erect which is where it gets it name) which is unlike many other genera that are diagonally or horizontally angled. It would be nice if I'd found this piece with the accompanying mold from either side as that would have more detail. As it is, the fossil does not have the hinge line preserved which should be shorted than the body length with a wing on the right side and a short ear on the left side.

What does the fossil have that helps with the ID? Well, as I mentioned before, the body is vertically aligned and longer than wide as well as having an umbo that narrows slowly.

This anterior view shows that the left valve is somewhat convex while the right valve is only slightly convex.

Side view of the left side of the piece

Side view of the right side of the piece

A view of the right valve shows some faint, concentric growth lines

Due to the size and shape of the specimen I am keeping my initial ID of Actinodesma erectum. Another possible match could be Mytilarca oviformis, but that species has a much shorter hinge line, both valves are convex to the same degree as the other and the umbo is pointed. Actinodesma erectum (Conrad) Hall 1877 is the accepted name for this fossil which formerly was known as Avicula erecta Conrad 1842 & Glyptodesma erectum Hall 1883. Thanks to Karl Wilson for the taxonomy history lesson.

Paracyclas rugosa pelecypod from the Panther Mountain formation

I broke this fossil while trying to hand trim some of the excess rock from around it but it glued together pretty well. It's a Paracyclas rugosa from the Panther Mountain formation (Devonian, Givetian) at Cole Hill in Madison County, NY.  Paracyclas rugosa is a small pelecypod that is nearly circular in outline and sometimes can be confused with a terebratulid brachiopod.

I've posted several examples of this genera before from the Silica Shale, Mahantango Formation, Arkona Formation, Jeffersonville Formation and Lime Creek Formation.

Cornellites fasiculata pelecypod with a bryozoan from the Panther Mountain formation

This rock is full of fossils but the one that made me keep it was the impression of a Cornellites fasiculata pelecypod. The detail of the mold is really nice but there is a little "window" in the mold that shows evidence of an encrusting bryozoan that had colonized the shell.

This is the whole rock with the impression near the bottom. The rounded object just above it (and casting the shadow) is the pygidium of a Dipleura dekayi trilobite.

When you look into the shadowed area you can see the "window

Here is a closer view and the cool thing is that you can see the clam shell, the base of the bryozoan and what looks like a worm tube that may have been on the shell before the bryozoan. The undulating shape of the bryozoan makes me think it could be a Leptotrypella species.

This fossil came from the Panther Mountain formation (Devonian, Givetian stage) at Cole Hill Rd., Madison County, NY

Bembexia sulcomarginata gastropod from the Panther Mountain formation

This is a pretty decent gastropod specimen from the Panther Mountain formation (Devonian, Givetian stage) at Cole Hill, NY. It's a Bembexia sulcomarginata and retains a little of the original shell texture. The curved lines that are perpendicular to the shell spiral are key to identifying this species. Despite the presence of the shell texture, this is still considered a steinkern (or cast) of the specimen. It has a nice three dimensional shape and is missing just the tip of the spiral.

I've also found this genus in the Needmore Shale of Pennsylvania.

Lyriopecten orbiculatus pelecypod from the Panther Mountain formation

The pectin like pelecypods of the Devonian can be beautiful with their regular concentric ornamentation highlighted by radial ribs and "wings" along the hinge line. The fossil below is one that I do not recognize but I think I found a name for it while perusing the "Field Guide to the Devonian Fossils of New York" by Karl A. Wilson, 2014, Paleontological Research Institution.

On page 148-149 is a pelecypod called Lyriopecten orbiculatus whose description is

 "Roughly circular shell with short hinge line, very small to absent anterior ear, and small posterior wing. Left valve convex, right valve slightly convex to concave. Surface marked by strong rays crossed by sharp concentric growth lines."

The shell I found is a right valve, although it's seen in reverse as it's a mold of the original, slightly convex with strong rays and concentric growth lines. It came from the Panther Mountain formation (Devonian, Givetian stage) in a quarry along Cole Hill Rd. in Madison County, NY.

Cypricardella tenuistriata pelecypod from the Panther Mountain formation

These next two specimens are Cypricardella tenuistriata pelecypod fossils. Both have the typical ovate shaped shell with a squared off posterior margin. The fact that the growth lines are very fine and not terribly distinct or raised eliminates the species C. bellistriata from contention.

Both fossils came from a roadside quarry on Cole Hill Rd. in Madison County, NY and come from the Panther Mountain formation (Devonian, Givetian stage) but the rock type is very similar to portions of the  Skaneateles formation (with which it is concurrent).

Specimen #1 - Right valve only

Specimen #2 - Left valve only