Big chunk of bone

[Jakuzi]

I found this big chunk of bone on the North Sulphur River last Sunday.  I know IDing the exact animal or what part of the animal could be difficult.  Just looking for any info.

Marine reptile, mammal, or dinosaur? Age? 

[Jakuzi]

[DinoMike]

 Texture looks like marine reptile of some sort. Probably Ozan formation, which makes it somewhere in the 78 million year range.

[Bronto]

Spongy inner bone with a red/ brown colour. Is often extinct elephant or giant tortoise of some sort. Maybe a hip fragment. The Sulpher River bed is significantly older. So it would have to wash in from a higher area or a covered over much younger gravel bend of a long ago river.

 

[Jakuzi]

Thanks guys.  Looks like it's still a bit of mystery chunk.