Devonian Fish Bone to ID????

[minnbuckeye]

I had previously posted this in a Post on a fossil hunting excursion to a Devonian site in Iowa. Since then, the bone has been cleaned up and substantially more bone exposed. I am hoping someone might ID the bone. But probably just a bone chunk! You don't know if you don't ask!!!  

 

 Mike

 

 

Edited July 6, 2021 by minnbuckeye

[Fossildude19]

Fragmentary bones are tough. 

Could be part of a pelvic girdle? Not sure, though. 

 

@jdp

 

Image from this PDF.

 

[jdp]

It does look superficially pelvic-girdle-esque but the texture in cross section looks placoderm-y. 

[minnbuckeye]

6 hours ago, jdp said:

It does look superficially pelvic-girdle-esque but the texture in cross section looks placoderm-y. 

@jdp Most hunters say placoderm when they find a piece of bone in this quarry. Are you insinuating placoderms do not have the pelvic girdle? 

 

 @Fossildude19, that pelvic girdle sure looks like it. Even the triangular shape on the right side of the pelvic girdle image!!

[jdp]

No, I meant in terms of the comparison with sarcopterygian fishes, specifically tristichopterids. It looked superficially like a tristicophertid pelvis as noted by @Fossildude19 but the bone microstructure just isn't consistent with that. If it was endochondral bone from a tristichopterid, there would be a much thinner cortex and a relatively sudden transition from cortical to trabecular bone, with much finer and widely-spaced trabeculation in the latter. The microstructure does look more placoderm-y and specifically arthrodire-y. However, I am hesitating to commit to that ID because I am not quite certain what element this might be.

[Fossildude19]

1 minute ago, jdp said:

No, I meant in terms of the comparison with sarcopterygian fishes, specifically tristichopterids. It looked superficially like a tristicophertid pelvis as noted by @Fossildude19 but the bone microstructure just isn't consistent with that. If it was endochondral bone from a tristichopterid, there would be a much thinner cortex and a relatively sudden transition from cortical to trabecular bone, with much finer and widely-spaced trabeculation in the latter. The microstructure does look more placoderm-y and specifically arthrodire-y. However, I am hesitating to commit to that ID because I am not quite certain what element this might be.

 

Thanks for this explanation!  This makes complete sense, to me. 
I know very little about Devonian fishes, and was making a best guess-timate.  

So glad I can learn here about them!