Mazon Creek Insect Wing? (Piece Of)

[PaulB]

This was collected 3 years ago in the Mazon creek area. It just broke open after 2 nasty winters outside in my Park Ridge backyard. I'm pretty sure it is a piece of an insect wing, but any information or ideas about the species, family, age, etc. would be appreciated. This is the best half of the fossil. There are fewer clear veins on the other half.

Thanks in advance.

BTW the minor axis is about equal to the diameter of a nickel.

[RCFossils]

Definitely not an insect wing.

Judging from the pictures, I think it is either a partial coprinoscolex or possibly sea cucumber.

[fossilized6s]

Definitely not an insect wing.

Judging from the pictures, I think it is either a partial coprinoscolex or possibly sea cucumber.

I agree. The "leathery" texture is the defining characteristic here. I can't see one, but if there is a "O" shape present in your specimen then it is a Sea Cucumber for sure. That was it's mouth.

[PaulB]

Thank you both for replying.

Yes, now that I looked more carefully through my Richardson's Guide, I see the sea cucumber photo on page 224 and my specimen definitely looks like the back end of that one. Unfortunately there is no evidence of the mouth - nothing resembling a ring anywhere, and no tube feet, which I understand are very rare.

I first thought insect after a cursory look through Richardson's. I saw the photo of Herdina Mirificus on page 192 and the random veining in my fossil looked similar to that in the photo. I guess I didn't page on to the chapter on Echinoderms.

As I understand it, sea cucumbers are fairly common in the Mazon Creek fauna, but rare in the fossil record elsewhere. Is that true?

Thanks again for helping. This just might re-engergize my interest in collecting and studying fossils. Many years ago it was a passion of mine. At one point in the 1990s I was even taking graduate level courses in Paleobiology at the University of Chicago. I had a course with Sepkoski, a seminar with Jablonski, and met Paul Sereno once (he sat in on one of Sepkoski's lectures). It was a fun time.

[Auspex]

...Many years ago it was a passion of mine. At one point in the 1990s I was even taking graduate level courses in Paleobiology at the University of Chicago. I had a course with Sepkoski, a seminar with Jablonski, and met Paul Sereno once (he sat in on one of Sepkoski's lectures). It was a fun time.

Legends of Paleobiology all! I am envious.

[fossilized6s]

Yes Paul, Sea Cucumbers are very rare in the fossil record, as are most soft bodied creatures. Mazon Creek is one of the few places in the World they are found. Mazon is a treasure trove of soft bodied fossils (it's a wonderful place) And yes, I would say Sea Cucumbers are fairly common there.

[Diceros]

A minor addendum on sea cucumbers being soft-bodied. Embedded in their skin, there are tiny calcite sclerites (some shaped like anchors, and some like oval sieve-plates, full of tiny holes). The Tertiary fossil record of these plates in screened marine sediment actually isn't bad in the fossil record, it's just that they're hard to identify beyond "sea cucumber". They're also nothing like the squashed whole ones in m. Pennsylvanian siderite concretions in the marine Essex fauna at Mazon Crk.