Please ID jaw and tooth fossil

[idunnoaname]

Hello, new here from Ontario Canada. I purchased this fossil in a store, labeled as miscellaneous marine fossils, and unlike the rest that were various bits of old coral and such, this one caught my eye.

 

I bought it but unsure if it's a mosasaur, plesiosaur, or something else entirely. Thought I'd get an opinion here.

 

A couple views I could provide including one with measurement comparison. Unit is in Inches.

 

 

Edited 2 hours ago by idunnoaname
Editing location

[Ludwigia]

Looks to me like an Enchodus.

[idunnoaname]

18 minutes ago, Ludwigia said:

Looks to me like an Enchodus.

Oooh that does look like a match! Thank you!

That actually makes me a little more excited about it over my other guesses haha I love fish