Upper Carboniferous (Duckmantian) Fish/shark tooth from coal measures. N. Wales.

[Skatetom]

 

Hi people! I'm a PhD student studying a Duckmantian fossil forest in North Wales. I have found these phosphatic fish/shark? teeth and scales I need an ID on. I suspect they are Adamantina Foliacea (Cuny and Stemmerik 2018) but that is a marine shark and this sequence is almost certainly completely freshwater and thought to be an upland swamp. I'm currently doing isotope work on the nodules and plant fossils and that appears to be confirming this is a completely freshwater system.

 

Anyone have any ideas? 

 

You'll have to click on the images again once you've opened them to zoom in! Sorry for the poor quality! 

 

Thanks,

Tom

Edited April 13, 2022 by Skatetom

[Fossildude19]

@jdp   @Archie

 

Cropped and contrasted:

 

 

 

[Tidgy's Dad]

Hello, and a very warm welcome to TFF from Morocco. 

By a very weird coincidence I was reading Cuny and Stemmerik's paper quite recently. (Mainly because my name Is Adam and I'd been looking up fossils with 'Adam' in the name. Ahem.) 

https://2dgf.dk/xpdf/bull66-47-60.pdf

Your specimen does bear a resemblance to Adamantina foliacea ( Ivanov 1999 ), but, as you say, it probably isn't. 

As to what it could more likely be assigned, I'm afraid I have absolutely no idea. 

Intriguing. 

 

[Skatetom]

Thanks for those images @Fossildude19!

Intriguing indeed isn't it!! It'll be the first vertebrate fossil from the site whatever it is!

[ckmerlin]

Hi Tom it's Chris from n NEWRigs glad to see you made it on here with the scales and tooth 

I sent you an email  

it's great that these fossil  finds are the first vertebrae evidence for the fossil forest site!!

[jdp]

I'm seeing a lungfish tooth plate. That could be a function of fortuitous breakage, but it really does look a lot like juvenile lungfish toothplates I've seen and/or worked with.  The other elements might be associated cranial elements or could be a smattering of other bone or tooth bits from something else. 

 

I'd compare with Monongahela stenodonta (Lund 1970). I figured similar toothplates for another gnathorhizid, Persephonichthys chthonica, as well: https://journals.plos.org/plosone/article/figures?id=10.1371/journal.pone.0108542. You might be able to ID the remaining skull bones there if that's what they are. Another possible comparison would be Palaeophichthys parvulus, though the current state of descriptive work of that animal is pretty poor.

[Skatetom]

Update! Managed to get SEM images of the suspected tooth plate and other fragments. From quick elemental analysis they're not phososphatic... Been in touch with Timothy Smithson from Cambridge uni and he thought it could be a Xenacanth tooth (This was before the SEM image).