Mazon creek Fossil

[Dean Sr]

Got this fossil passing through Illinois at a flea market with a whole box of mazon creek fossils this is the only one I could not identify it looks like an insect any ideas thanks again Dean Sr.

[Innocentx]

I suppose that on many occasions, unidentifiable pieces of plant detritus have been fossilized. This may be an example.

[Fossildude19]

I agree - looks plant-like to me. 

Let's wait 'til we hear from some of our Mazon collectors.  

@fiddlehead

@RCFossils

@digit 

@fossilized6s

[fossilized6s]

That's a tough one. My first impression is coprolite, because of its chunky calcite look. 

 

Let's see what others think. 

[digit]

I could get behind coprolite (no pun intended). From what I can see the potentially linear shaped (plant?) material seems to have an alignment to it. That might be support for some sort of plant detritus as I imagine any plant material in a coprolite would be more randomly oriented. Show me an obvious Mazon Creek fossil and I could boast at least a 50% guess rate but I'm rubbish on these sort of ambiguous fossils--just haven't seen enough of them to make inferences. I'm better at that with Peace River fossils of which I've seen my share.

 

Looking forward to hearing from the more experienced Mazon Creek collectors on this one.

 

 

Cheers.

 

-Ken

[CBOB]

Could you include a size?  If I really squint I almost see a smashed segmented insect abdomen?  But that's squinting really hard.  I would be more on board with plant debris as my vote.

[Dean Sr]

There are segments about 3/4 of an inch crushed it looks like faint wings are also present thanks for looking I will try to get another picture 

[fiddlehead]

This is a very unusual looking something. I can say with high confidence this is not something related to plants. The preservation looks to me to be cartilage or bone. If so, it is likely shark or bony fish. Possibly a partial and slightly disarticulated fin section. Complete tail and/or fins of large fish have been found in Mazon Creek concretions, so such things are possible. That said, this would make it rare, if not one of a kind, and makes a final determination difficult at best. 

 

Hope that helps,

Jack

[Fossildude19]

What is the width of the nodule?

[Dean Sr]

It is about 1and 1/8 " in circumference ! !

Edited December 27, 2016 by Dean Sr
Adding a photo

[RCFossils]

I am leaning towards coprolite.

[trisk]

1 hour ago, Dean Sr said:

It is about 1and 1/8 " in circumference ! !

Did you mean diameter?

 

Cropped and enhanced the first photo:

There are repeated linear forms in this, appearing to terminate in lobes at one end, and segmented at the other. They seem to be impressions, but some flakes of lighter material remains at the ends. The majority of this material either flaked off or was attached to the other half of the concretion. Can you take closer up photos of those areas?