Mazon Creek: Coprinoscolex Ellogimus?

[araucaria1959]

Hello,

I bought that specimen labeled Coprinoscolex ellogimus.

I'm not really convinced that this ID is correct. Maybe it is compressed and distorted and thus not as worm-like as usually. I show pictures of both sides (counterpart).

There is a second question. There are small wormlike structures on the surface of the specimen. However, they don't look like tubeworms. Maybe they are some kind of coprolite, or the sandy content of the intestine of the animal that left the intestine at several places due to injuries. If so, there must have been multiple injuries which may indicate that the animal became the victim of a predator?

araucaria1959

[snolly50]

I have no first hand knowledge of this fossil. I did enjoy looking it up in an effort to satisfy my curiosity. The Fossil Fauna of Mazon Creek, Shabica and Hay, eds.,1997 was employed. The text reported this is a "common species of the Mazon Creek fauna. To my eye the illustrations looked very much like your piece, albeit yours with a fatter mid-section. The proboscis does not appear in yours, but "capable of detaching...when disturbed." The text also reports, "convoluted gut sometimes visible...numerous rice-shaped fecal pellets." This is what I believe I am seeing in your photos.

Thanks for posting a very interesting fossil. I hope someone with some experience with this animal will comment.

[araucaria1959]

Yes, the fat mit-section is the problem which caused my doubts. I have a few specimens of Coprinoscolex for direct comparison and their shape is more worm-like. Maybe the central part was expanded after death. The rice-shaped fecal pellets are a very plausibel explanation for the structures I mentioned in my second question. Thank you very much - you found exactly the information I was looking for.

araucaria1959

[Carl]

I would go with Coprinoscolex. The first part of it's name refers to the minute coprolites that are usually (always?) found in its guts. So jealous... Got any more of these lying around?