'distribution info given on the Guide page' IS NO GROUND FOR ID! Such approach undermines the integrity of the site. Not to mention the fact that no positive ID on this image have ever been provided.

the other two images on the S. californicus page look very much like my photo, and they were identified by two grad students who have considerable experience in identifying beetles, so that gives me reason to believe that at least the genus is correct.

And a search on Google for Stenomorphus found an excerpt from page 95 of American Beetles by Arnett et al, quoted here:
"Three species range into southern United States: S. californicus Menetries 1843 is widespread in Mexico, and occurs from western Georgia to California in United States; S. convexior Notman 1922 is known from southern Arizona and western Mexico; S. sinaloae Darlington 1936 is known from southern Arizona and New Mexico."

The distribution info I put on the Guide page came directly from the above quote. My photo was taken at the southern tip of Texas, which is a considerable distance from New Mexico, Arizona, and western Mexico, so I think it's reasonable to assume that my photo is not S. convexior or S. sinaloae. By the process of elimination, that leaves only S. californicus.

If you don't think this is Stenomorphus californicus, what do you think it is?

I’m not saying this is not S.californicus. And I’m well aware of what American Beetles says about Stenomorphus. That’s not the point. I agree that “the other two images on the S. californicus page look very much like photo”, but it’s not enough. They may look so to me or you but only an opinion from someone familiar with the genus and all of its members will matter. I also agree that “it's reasonable to assume that my photo is not S. convexior or S. sinaloae” but no assumption would constitute a positive ID. Positive IDs may not be made based on circumstantial evidence. In this case, neither you or I are equipped to make one.

Non-expert volunteer editors use their own judgment to move photos to various places in the Guide many times a day. If we had to wait for "positive IDs" from experts who are "familiar with the genus and all of its members", virtually nothing would get done, and the huge excess of unidentified photos would be an even worse problem than it is now.

We try our best but we're not perfect; that's why there's a Disclaimer at the bottom of every page.

I've explained why I think my photo is Stenomorphus californicus, and my reasoning is not reckless or frivolous. The onus is now on someone else to explain why it is NOT that species or genus. Until that happens, I'm willing to leave the photo where it is because I believe the ID is very likely correct.