Fossil... but of what?

[DigEmAll]

Found this in a wash here in SE Arizona a while back.  Anyone have a clue what it is?

I know it's a fossil, but of what?

It has a cross section shape of a bean. Kinda "C" shaped.

Notice in the second picture how it indents in the mouth of the "C" shape.

It kinda reminds me of a spine, but I know it isn't. LOL

 

Amazon Forum Fav 👍

Agony and Death on a Gold Rush Steamer: The Disastrous Sinking of the Side-Wheeler Yankee Blade - Grab it through Amazon!

[PBK]

Maybe a piece of an ammonite cephalopod.

 

[DigEmAll]

I do believe that that is it... or at least something very similar. 

Thank you sir.

 

[Mackaydon]

Looks to me like a bivalue; opens like a clam.
Don.....

 

[irbaddadjoe]

its what pbk said. part of an ammonite.

 

[romeo-1]

I was thinking mastadon molar...

 

[EDDE]

Maybe a piece of an ammonite cephalopod.

CORPALITE ^