Moved from Hide Beetles.

There are three look alikes in that area that are pretty much indistinguishable without the male genitalia: sonorae, contractus, and robinsoni. Trox sonorae usually has dark antennal clubs, but...
Trox tuberculatus is also a possibility, but that species generally has longer elytral setae and more elevated tubercles; the four setal tufts that are diagnostic for that species would be covered in dirt in the above specimen.

Moved from ID Request.