Mystery Tooth - Croc or Dino?

[Bone Daddy]

Got this tooth in a trade package. The exact locality is unknown, but is somewhere west of the Mississippi. It seems similar to the gator and croc teeth I have found down here in Bone Valley Florida, but the interior structure appears different. Any ideas what this might be?

 

[PalaeoArt]

Looks more like Horn Coral than a tooth (as it's missing the enamel)

 

[Fossildude19]

I agree - this is a very water worn Rugose coral.  

Regards,

[Bone Daddy]

Thanks folks. A worn coral never occurred to me.

 

[abyssunder]

It's a pretty nice example of solitary rugose coral for studying the morphology.