Yet another mystery bone from the boulonnais (France)

[ADfossils]

Hello everyone!

 

Here I am with another mystery bone from the boulonnais (Wimereux) region - North of France. The layers here are kimmeridgian and titonian (late Jurassic).

 

I have a few pieces that I’ve collected over the course of 3 days all at the same spot. I managed to match the first three pieces, with two pieces that I already glued together since I was 100% sure of how they fit together.

 

The first two pieces together:

 

 

Then, I have this third piece that also match but I didn’t find the perfect angle to glue them yet:

 

 

And together, they would look like this:

 

Total size would be 15 cm broad and 20+cm long (that’s 6 inch broad and 8 inch long).

 

Now I was thinking about part of (distal end) a plesiosaur propodial. But I’ve found a couple plesiosaur and pliosaur propodial from there and they are way flatter at the end. Also, they are mostly the same shape on both sides. Whereas here the « upper part » (the two pieces already glued together) are chunky on one side and flatter on the other side.

 

Has anyone got an idea?

 

Thank you very much!

 

[ADfossils]

No one? 

[pachy-pleuro-whatnot-odon]

On 4/21/2024 at 3:12 PM, ADfossils said:

Now I was thinking about part of (distal end) a plesiosaur propodial. But I’ve found a couple plesiosaur and pliosaur propodial from there and they are way flatter at the end. Also, they are mostly the same shape on both sides. Whereas here the « upper part » (the two pieces already glued together) are chunky on one side and flatter on the other side.

 

My first thought is distal end of a pliosaur propodial too, not only going by shape, but also frequency of their finds in this region. These propodials can have varying shapes depending on species, with some the distal end in some species being somewhat offset from the central axis. In plesiosaurs, in contrast, the flares on either side are usually more equally balanced, yet not typically rounded, as in pliosaurs, since in plesiosaurs the paddle digits interlock with the propodial.

 

(source)

 

Also compare with these paddles on display at the Paläontologische Sammlung, MUT Tübingen.

 

 

All this having been said, I'm very interested in what exactly you mean with "are chunky on one side and flatter on the other side"...

[ADfossils]

Thank you @pachy-pleuro-whatnot-odon! 

 

With « chunky on one side and flatter on the other side » I mean the propodials that I’ve found and seen are often the same shape at both sides (not the ends, really the sides). Given it a form like a, well like a paddle, right?

 

 

(See video)

 

Here both sides are not equal, with « the back » being smoother.

 

I am still trying to figure out if other pieces fit, maybe it will become more clear once it is more complete also!

[pachy-pleuro-whatnot-odon]

I see what you mean... And when it comes to that, I agree that the one more concave and one more convex end on the distal articulation make it look more like a long bone from a terrestrial animal, potentially dinosaur, rather than a marine one.

 

Aren't the occasional sauropod bones found in this area as well? @sjaak

[sjaak]

The Boulonnais is full of mystery bones. Problem is that most bones are partial and eroded. I doubt you will get a good id on this bone fragment.