Large claw (crab?)

I found this hamburger looking concretion and could see there was definitely something inside. My first throught was a crayfish because of the curve visible on the side of the rock. I took it home and removed the top which was already loose. Turns out it was a gigantic claw of some kind. I'm not sure what species it would be from.

I spent some time prepping it to try and expose more of the crab and made sure that the "lid" could still fit afterwards.

Here is a link to the prep: Prep video

Watch the video of it being found

Age: Miocene