Pennsylvanian Illinois

[aek]

Hi, I found this fossil last year on a trip to the Starved Rock Clay Pit. I didn't find out what it was until just recently: a spine from a shark/eel-like creature called Listracanthus.

 

My question is what is on the other side? Looks like a zig-zaggy impression of some sort. Thanks for any help.

 

[aek]

Another view..

[Fossildude19]

Welcome to the Forum.

Cool fish spine!  

 

Your other item looks like a fish scale, to me. 

Maybe something akin to Strepsodus?

Regards,

[Missourian]

I was thinking it's just a calcite-filled fracture, but I'm hoping for a huge fish scale.

[Xiphactinus]

Conularia?

[FossilDAWG]

That Listracanthus spine is amazing! 

 

Don

[caldigger]

If that thing is a scale, it would have been one scary sized fish!  

I know it's been more than an hour after I ate, but I'm still staying out of the water!!!

[Nimravis]

12 minutes ago, caldigger said:

If that thing is a scale, it would have been one scary sized fish!  

I know it's been more than an hour after I ate, but I'm still staying out of the water!!!

Lol-

[TqB]

17 hours ago, Xiphactinus said:

Conularia?

 

I was wondering about conulariid too, there are patches that look really rod like but it's unusually flattened for one. There are possible corners and centre lines though...

 

[doushantuo]

Conulariid,based on outer morphology.

[Fossildude19]

That would have been a huge conulariid.   

 

My thought was Rhizodont of some kind, which would not be out of the realm of possibility, size wise.

 

    

 

But,  @Missourian may have a point about calcite. 

 

 

 

[TqB]

Just now, Fossildude19 said:

That would have been a huge conulariid.   

 

 

A good size but well within normal range.

[TNCollector]

I vote flattened conulariid. I have found some nearly three times that size in different localities.

[aek]

Thanks for all the replies on this enigmatic fossil. My initial thought was some sort of plant impression, as plant material can also be found at this location although I'm not sure if in the same black shale layer. I can see it could possibly be a flattened conulariid , and if so, makes a doubly intriguing specimen featuring two odd and poorly understood faunas.

[doushantuo]

I might have posted this before,dunno:

 

 

protected,so no outtake

recommended,of course

 

it covers ground similar to:

 

simovanitnconularitaphonjt009web.pdf