...Anelaphus niveivestitus is a south Texas species and not known from Arizona. It is also a relatively smaller species and with the pronotum less rounded.

I'm less inclined to say Enaphalodes now, which are rather robust. Perhaps Orwellion gibbulum arizonense.

I agree about distribution, but body length of that specimen is actually unknown.

They're really two very similar species and the length of elytral spines doesn't look so much different.... difficult also to see in that pictures....

...in Anelaphus it is usually ~1/2 the length of the pronotum, while in Orwellion it is ~2/3 the length. Looks to me like the latter in these photos.

The description above does indicate "larger" - which is why I originally thought of Enaphalodes. Orwellion can also be considered "larger" (though not as large as Enaphalodes), but few Anelaphus would be considered as such.

I have large series of both species in my collection - they are quite different.

Still, a better photo is needed for positive ID, although it is definitely in the tribe Elaphidiini.

p.s. did you receive my email reprint request?

Yes, did you receive my reply?

I couldn't get there without your help! Do appreciate it!