Help id this jaw piece (maybe other stuff?)

[Fossilsupremacy]

Found a pretty cool fossil yesterday- has what definitely looks like some fossil teeth in it, along with a tiny, almost shrimp or krill looking creature. Here are the photos- 

 

fossil is almost 8 centimeters tall- a little over 3 inches for my american friends.

it’s a bit hard to measure the width cause it’s a little wonky shaped and math isn’t my strong suit… you’ll have to go with this for now.

[Kane]

To my eye, this looks like the ridges on a brachiopod or similar shell-based creature.

[Ludwigia]

Or an oyster. Not teeth anyway, although they do leave the uninitiated with that impression.

[Fossildude19]

I'd go with a cross section of some sort of oyster.

 

No bone or bone texture for jawbone, and no enamel, so they are not teeth.

 

Maybe something like Rastellum sp?

[ClearLake]

Yep, I agree with @Fossildude19, looks like the edge of a Rastellum to me.