Contacyphon hilaris

This genus was formerly known as Cyphon and many references have this species listed as Cyphon hilaris.

This keyed (using Duff) to hilaris but I wasn't completely conviced the rear of the elytral suture was dark enough, and if not it could have been ochraceus (the dark rear suture looked good in the live photos but under the microscope it didn't seem to differ so markedly from the front of the elytral suture). Gen det secured the ID as hilaris, though I was (not for the first time in this genus) caught out by what to me seem quite unusual genitalia. The median lobe looks quite unlike what I think of as a typical beetle median lobe, what I now know to be the 8th and 9th tergites somewhat resemble the apodomes of many female insects and the tip of what is known in German as dorsalstück resembles the tip of a female ovipositor in some insects, at least to my eyes. Fortunately the confusion was short-lived as the median lobe in this species is highly distinctive and shown well in Duff. The Käfer Europas website shows this along with the 8th and 9th tergite and "dorsalstück", which all helped reassure me that it really was a male!

male Contacyphon hilaris showing its hind tarsus, pronotum (2 views), rear of elytra and genitalia (2 views, first just the median lobe), Wendling Beck Environment Project (Norfolk, UK), 8th September 2023