Prionychus ater

Described as scarce.

The ID of this beetle was fairly straightforward. The ventrally-lobed penultimate tarsal segments could be missed by inexperienced folk who are used to tarsal lobes being visible from above, but the "ventrally" is a clue! Viewed side on the extension along the ventral side was perfectly clear.

The only character separating ater from melanarius that was at all doubtful was the elytral epipleura which were very slightly concave (partly accommodating the hind tibia). But they could hardly be described as "distinctly concave" and were nearly flat. The other characters checked out fine and the reticulate microsculpture on the pronotum and elytra was very clear under high magnification.

Prionychus ater showing hind tarus, prosternum, elytral epipleura, pronotal sculpturing and elytral sculpturing, North Elmham (Norfolk, UK), 22nd August 2023