North Sulfur River Fossil Bone

[dannbethrfriends]

I found this near the Ladonia fossil park a few months ago, just the very tip was peaking up out of some sand. It's persistently bugged me ever since because, as you can see, there's actually very little area where the bone surface is not preserved, and yet I can't make heads of tails of it. 

 

IT's about 10cm/4inches from corner to corner, I'll treat this as an approximate cube and walk through the 6 sides:

 

The "top" as I happened to find it has a straited texture and is fairly flat and complete except for a growth that starts on the right-hand side as shown below and is clearly broken off. This then shifts into a joint-like structure shown in the bottom of this picture which seems to have a small chunk missing. 

 

 

        

 

This ball-joint-like structure is shown here. Below that structure is another break which clearly would have been the largest missing piece.

 

 

   

 

Moving to the side of the ball there is a smooth section shown here.

 

                 

 

 

The opposite side from this is highly ridged with deep channels

 

            

 

The side opposite the ball-like structure brings these ridges together

 

    

 

Finally, the "bottom" as I happened to find the piece is straited and strongly textured almost, but not quite, at least to my eye, like fish bone. 

 

 

 

Really appreciate any thoughts!!

 

 

 

[JohnJ]

My best guess is part of a mosasaur basioccipital or part of the prootic...all unusually shaped parts of the skull.

 

@Jared C

@Praefectus

@pachy-pleuro-whatnot-odon

[dannbethrfriends]

Thanks so much for the thoughts. That gave me the search terms to find a paper by Dale E. Russell with this schematic of the opisthotic which seems to match perfectly. So I guess the ball structure is the paroccipital process.

 

Bulletin. Natural history. RUSSELL: AMERICAN MOSASAURS 35

[Shellseeker]

13 minutes ago, dannbethrfriends said:

Thanks so much for the thoughts. That gave me the search terms to find a paper by Dale E. Russell with this schematic of the opisthotic which seems to match perfectly. So I guess the ball structure is the paroccipital process.

 

 Kudos to both you and @JohnJ

I am truly impressed by your photos, analysis, and presentation of this random bone.  It is one of the best initial write_ups for a bone on this forum in 15 years. and certainly Johnj is a Texas resident expert who knows the Geology , layers and fossils in the Ladonia fossil park .

 

Your follow_up is exceptional.  I know because tracking down research in difficult.  I hope you stick around and contribute to the Forum....

[dannbethrfriends]

On 9/8/2024 at 9:57 AM, Shellseeker said:

 Kudos to both you and @JohnJ

I am truly impressed by your photos, analysis, and presentation of this random bone.  It is one of the best initial write_ups for a bone on this forum in 15 years. and certainly Johnj is a Texas resident expert who knows the Geology , layers and fossils in the Ladonia fossil park .

 

Your follow_up is exceptional.  I know because tracking down research in difficult.  I hope you stick around and contribute to the Forum....

Thanks, Shellseeker! I will definitely stick around, it's pretty amazing to have such a deep, knowledgeable, and generous community!