bug experts..what is this big beetle? so. maine location

[klf73]

So my son was sick a few weeks ago and I pulled his seat to wash...so many kids I had extras so I rinsed it and set aside and used a different one. I pulled it off today and I guess while it was outside this guy crawled in and got stuck and died.
Quarter for comparison

 

[Flyingbavarian]

Closest thing i could find.

http://bugguide.net/node/view/5031

 

[klf73]

Looks like it

thanks