Unidentified museum object

[James SWM]

Sadly this fossil comes with no information on find location. I can only say UK. All thoughts welcome! It seems vertebra-shaped to me, but ichthyosaur doesn't seem quite right. The piece is about 6cm thick so the hole through the middle doesn't seem like erosion through the thinnest part of a biconcave disc, I don't think the concavity that remains is pronounced enough. The hole is definitely more like a 'channel' - maybe 3 cm long.

[jpc]

Doesn't quite look bone-ish, but indeed the shape suggests ichthyosaur.  I am curious as to why you call it a museum object.  Was it found in a museum basement?  

 

[James SWM]

41 minutes ago, jpc said:

I am curious as to why you call it a museum object.  Was it found in a museum basement?  

 

Almost literally, yes. I work in a local Museum and it is one of many objects donated to the Museum in the 19th century with very little information now known about it.

It is a confusing piece, I agree. A few people have been saying ichthyosaur, but my hesitation until know is that it looks so different from other ichthyosaur vertebral material I've seen. Although based on this growing opinion, the material I've seen so far must be much more highly eroded.

 

[jpc]

I also work in a museum, so I understand that.  I really doubt this is ichthyosaur... the cross sections look more like limestone than bone.  

[digit]

16 minutes ago, jpc said:

the cross sections look more like limestone than bone.  

Agreed. This looks like limestone with a solution hole in the middle. From the side the small cavities look more like boxwork than cancellous bone (the spaces would be more uniform and rounded).

 

https://en.wikipedia.org/wiki/Boxwork

 

This has likely been laying around for over a century as nobody could figure out what kind of fossil it is. The fact that it is geological rather than biological explains the mystery.

 

 

Cheers.

 

-Ken

[James SWM]

Thanks both for your input. I suppose I'm slightly disappointed that it isn't quite a large fossil vertebra, but I hadn't heard of boxwork before so I've learned something new and have a likely ID on a mystery object! Thanks again.