Fossilized bone from Western South Dakota

[zmo63]

Hello, I'm interested to know if there's any way to narrow down what kind of animal this fossil is from? My dad tells me it was given to him by my great grandmother, who likely purchased it from a university in Western South Dakota in the 1940s or 50s. Our assumption is that it would have been discovered in that area, around that time.

 

 

 

 

 

 

The fossil is about 4" x 1.5". I think it's so cool, but beyond guessing that it's "a bone" from "an animal that had bones," I'm at a loss.

 

Thanks for any help!

Edited November 29, 2022 by zmo63

[Troodon]

I don't believe what you have is bone looks more like a baculite which is found in western SD.  Invertebrate knowledgeable folks may shed more light on it.

[jpc]

Yes, this is a baculite.  Google baculite and you'll see.  

 

[zmo63]

Thank you both so much! I really didn't expect to be able to find a definitive answer, and never would have gotten there on my own since I was making all the wrong assumptions at the start. I'm thrilled to know what this actually is. I'll update the tags on this post for accuracy.