North Sulfur River bone question

[Creek - Don]

I went out to the North Sulfur River today and found these two bones.  First one is a mosasaur vert, second one which I also think belongs to mosasaur.   

[Creek - Don]

I'm thinking plesiosaur limb bone.

[PeterMichael]

Image 7 sure looks like an appendage (a "limb"). The hole is likely a channel for a nerve or blood vessel. Image 1B: L edge (proximal or distal?) looks like a socket (ball and...). Nice.

[Creek - Don]

17 hours ago, PeterMichael said:

Image 7 sure looks like an appendage (a "limb"). The hole is likely a channel for a nerve or blood vessel. Image 1B: L edge (proximal or distal?) looks like a socket (ball and...). Nice.

Thanks.  I'm lucky to be near NSR and finding these bones.  Most fossils I find are are invertebrates , and I do have plenty of those in my collection.