Green River Fish Plate And Mystery Fossil

[ottawafossil101]

Hello,

I have a question that might only be able to be answered by speculation.

I recently acquired a Green River, Wyoming fish plate (knightia) which is pictured below. It is an awesome piece and it seems like i'm always noticing something new.

When I got it, i noticed there was a bulging area on the 'backside' of this plate that had been chipped away to reveal what looks like a fossil. The layer revealed is the same color as the knightia fish and has a unique texture. The bulge raises above its surroundings approximately 5-7mm and the overall diameter of the area is about 4-5 inches.

Does anyone have any insight into what this might be? A flat, circular dome shaped fossil. The only thing that looks likely from what i see online is maybe the lateral portion of a stingray. A guy can hope right? What do you think?

Any info or help would be appreciated.

Thanks!

[stxhunter]

Sweet piece ! Very nice.

[Herb]

Nice plate of sardines! Maybe fish poop on the back?

[siteseer]

Herb,

I agree that it could be fish poop (coprolite). Coprolites in the Green River Formation are found in a variety of shapes and sizes (even several inches long) and can be relatively uncompressed (more of a 3D preservation that you would expect of poop)..

Jess

Nice plate of sardines! Maybe fish poop on the back?

[crinoid1]

I'll 3rd that. Definitely a coprolite. They are extremely common in the Green River Fm. Awesome fish plate!

Gabe

[old dead things]

Here are some Green River coprolites I have collected for comparison and preview.

The first photo is crocodile coprolite they are quite obvious, but sometimes you can see disruption in the limestone for many layers.

This photo is of several different sizes of coprolites from fish.

Many people think they found a snake, but no it is another coprolite.

Jim

Old Dead Things

[jpc]

I agree... it is lilely a coprolite on the back. Nice snarge there, Jim.

[ottawafossil101]

Shoot, now I can't argue with the wife when she says that all i buy is snarge! Lol. Thanks for the info guys!