Strange Pits

[Mediospirifer]

Looking at a new fossil site, my husband and I found a few rocks with features I've never seen before. These are Upper Devonian era, Gardeau Formation pieces.

I don't know what the pits in these rocks are, except that they put me in mind of arthropods, possibly trilobite. We found several rocks with these features:

This is a second rock with the same pits, also with some nice bivalves:

Here is a closeup of the pits:

Does anyone recognize these features?

[mikeymig]

The pits are where shells use to be. Stick some clay or play-doh in them and see what it looks like.

mikey

[Mediospirifer]

I can tell that the object was roughly spherical, mith little bumps like I've seen on some trilobites and a ribbed ridge, usually across the bottom of the pit. They're rather odd!

[mikeymig]

I have collected this material and I'm pretty sure that there were no trilobites around at this time. It's not impossible that a few trilobites existed here but not in these numbers.

Mikey

[ohiofossilhunter]

http://www.radford.edu/jtso/GeologyofVirginia/Fossils/GeologyOfVAFossils3-3b.html brachiopod external molds

Edited April 24, 2014 by ohiofossilhunter

[Mediospirifer]

I have collected this material and I'm pretty sure that there were no trilobites around at this time. It's not impossible that a few trilobites existed here but not in these numbers.

Mikey

Trilobites may have been rare in this formation, but they certainly existed during the Upper Devonian. I'm not saying that these are, just that I don't know.

http://www.radford.edu/jtso/GeologyofVirginia/Fossils/GeologyOfVAFossils3-3b.html brachiopod external molds

Mine don't really look like those, but I'll dig through the brach section of my NY Devonian book and see if I find anything that does.

If I find a match, I'll post it!

[Mediospirifer]

On a look through the brachiopod section of "Devonian Paleontology of New York", I didn't find anything that resembles these critters. So I kept turning pages, and found something that matches in the gastropod section: Aglaeoglypta koeneni. That's certainly a new one for me! I don't usually find gastropods when I go hunting, except the occasional modern snail or slug. Usually I find those in my garden.

[Fossildude19]

On a look through the brachiopod section of "Devonian Paleontology of New York", I didn't find anything that resembles these critters. So I kept turning pages, and found something that matches in the gastropod section: Aglaeoglypta koeneni. That's certainly a new one for me! I don't usually find gastropods when I go hunting, except the occasional modern snail or slug. Usually I find those in my garden.

Good job on the ID Mediospirifer! - I would agree with you.

Nice imprints - you should try the clay trick Mikey suggested - would be cool to see the results.

Regards,

[JeanB]

Very nice plates BTW!

Jean

[Mediospirifer]

Thanks for looking, everybody!

I will try the clay trick, and I'll post pictures here. It may be a few days--I don't have easy access to clay or play-doh! Maybe I'll try filling the holes with Jell-O.