Mosasaur/turtle bone ID? North Texas

[John S.]

Just found this bone out of the eagle Ford group in north central Texas. 86-90 mya. I'm guessing it's mosasaur or turtle? One end is broken off. 4 inches length. If so can we get a bone ID from it? Limb bone? Thanks for any help. 

[JarrodB]

Cool find. My turtle bones all seem lighter than my Mosasaur bones.  I think yours is turtle. 

[John S.]

Thanks Jarrod. Maybe turtle or maybe proximal end of mosasaur/plesiosaur propodial?

[John S.]

Mike Everhart from Oceans of Kansas confirmed this is indeed the proximal end of a plesiosaur propodial bone. Here is a shot of it combined with the distal end of a separate plesiosaur.