Odd Little North Sulfur River Bone

[ShadyW]

This is a funny little bone my wife picked up. It's basically a thin bone plate (completely flat on the back side) with a little stub of bone that sticks up from the other side. We actually found two, but the second has had the stub broken off. The plate is basically rectangular, and the edges (as seen in the foreground of this picture) look like they broke along a bone suture like on a skull. Anyone recognize it? I'm assuming it's Mosasaur, since that's 90% of the NSR vertebrate bones.

[Xiphactinus]

This is a funny little bone my wife picked up. It's basically a thin bone plate (completely flat on the back side) with a little stub of bone that sticks up from the other side. We actually found two, but the second has had the stub broken off. The plate is basically rectangular, and the edges (as seen in the foreground of this picture) look like they broke along a bone suture like on a skull. Anyone recognize it? I'm assuming it's Mosasaur, since that's 90% of the NSR vertebrate bones.

looks like turtle to me....where the shell "ribs" attach to the verts

[ShadyW]

looks like turtle to me....where the shell "ribs" attach to the verts

Thank you Xiphactinus! Now you say that, it makes perfect sense. The fracture lines along the sides of the bone looke just like the characteristic jagged edges of turtle shell plates.

I still can't quite work out where it would belong on a turtle skeleton, but from what I can work out, the protroding bone stub (or rib) was on the inside of the shell, and the smooth, slightly curved underside (which I didn't photograph) was actually the outside of the shell.

Thanks again!

[Uncle Siphuncle]

Looks like X beat me to the punch - turtle is my vote too. I have a valid excuse for my lollygagging response - I was out collecting Maastrichtian ammonites.