images using improved technique added for better detail (still, lighting this beetle proved very difficult for me).
I still can't determine this beetle. Appears to key (using D&A and Am Beetles) to Acupalpus (starting from Halpalini), based on 1) labial palpi with 2-3 setae, 2) mentum w/o tooth, 3) elytra with marginal series of punctures not grouped in 2 groups of 4. But no species of Acupalpus from D&A appears to match, nor does any have any mention of a pronotum with furrows like this one.

therefore, suggestions welcome, as always :)