Sharktooth Hill: "Oreo" maybe cetacean vertebra?

[ScottM]

Found this thing today in my Sharktooth Hill bucket-o-bones and my first thought was "fossil oreo" so I was very intrigued to learn that there actually are fossil "cookies!" I even think I found one (not posted here). But this one is a sandwich cookie. I have pics from top, bottom, and all around the edges. The large hole you can see from the edge view goes straight through all the way. 

 

If what I learned about "cookies" is applicable, I would imagine they would be like caps on the two flat surfaces of my bone, and are therefore missing on this specimen? So I guess it's a vertebra? Ideas on what animal, what part of the spine, (or how many million miles off I am) would be greatly appreciated. Thanks!!

[JamieLynn]

I have NO clue what that is, but just wanted to say I think that is really interesting looking.

[fossilsonwheels]

I believe that is Cetacean and it’s called an Ephiphysis, it’s a vertebra. Cervical Vert I think

[Shellseeker]

Welcome to the Forum, Scott....

You have what is likely a marine mammal vertebrae (because you found it in STH) of a juvenile animal.

It is not an Epiphysis, This is an Epiphysis:

Note that the photo on the left looks a little similar to your 1st photo.... The vert and the epiphysis are initially separate in the young mammal's life and eventually merge into one leaving the photo on the right as the outside of the vertebrae. This is likely an epiphysis of a dolphin/porpoise, but I have found epiphysis from land mammals.

 

So you basically have a 4 inch wide vertebrae of a marine mammal. It does not immediately scream WHALE or Dolphin to me, but I am far from an expert on West Coast fossils..

Maybe @caldigger or @Spoons

 

Good luck... Jack

 

 

[Ruger9a]

I also think it's very interesting.

[Spoons]

I’m at a loss here. A lot of the diagnostic features appear to be eroded away. 
 

It’s really small, only 4cm wide. This makes me think small dolphin or porpoise as well. Maybe a sea otter, although I can’t see any bones here that match.

 

Im currently looking through here to find a match:  https://virtual.imnh.iri.isu.edu/Osteo/Mammals/4

[caldigger]

It may be something similar to this cetacean vert. in an under developed form. 

[ScottM]

Thanks to all who responded - very appreciated! 

Sure looks like a porpoise-like vert. Still hoping that the pics (especially #2-4 showing the internal structure) will jog someone's memory. Caldigger's cetacean vert looks very similar (thanks for the side view - hard to find those online!), and I'm betting that's what I've got but the oreo "filling" on mine is so distinctive I'm still holding out hope that somebody recognizes it. This is fun and this is a great forum. :-)  

[ScottM]

3 hours ago, Spoons said:

I’m at a loss here. A lot of the diagnostic features appear to be eroded away. 
 

It’s really small, only 4cm wide. This makes me think small dolphin or porpoise as well. Maybe a sea otter, although I can’t see any bones here that match.

 

Im currently looking through here to find a match:  https://virtual.imnh.iri.isu.edu/Osteo/Mammals/4

Thanks for the link, Spoons! :-) Bookmarked.