NSR please help identify

[Stormywx]

I have a couple of these, this is the best specimen. I think they are from a mosasaur but only because they were found on the NSR. There are two indentions/holes that don't show up that well in the picture. The first picture shows the indention the best, there is a corresponding one on the other side. I apologize the lighting didn't make that more clear. If it helps in identification, I can retake pics. 

 

 

 

[hwwii2]

Looks like petrified wood to me..??

 

[eboe101]

This is a piece of fish bone

[GPayton]

Part of the neurocranium/skull of a Xiphactinus most likely. This looks like it corresponds well with the parasphenoid bone (essentially a low-slung bone that runs along the roof of the mouth) and the parethmoids. The parethmoids would be the two protrusions that point in opposite directions from one another. Here's a picture of the same bone that someone else posted on the Forum a while back that came from a Xiphactinus from Kansas. You have half of it, specifically the part visible in the bottom right of their picture.