Sepedophilus nigripennis

This my first Sepedophilus was found by suction. I keyed it to species using Duff with moderate difficulty. Subtle differences in structure were hard to call and the microsculpture on the pronotum hard to see. The middle segments of the antennae were slightly darker than the base and tip which was a challenge at couplet 3 but although it had wings, these were clearly short so not "fully-winged". Also what I could see of the microsculpture on the pronotum seemed to resemble reticulation more than transverse lines. The forebody length of about 1.5mm helped reassure me that I'd successfully elimated some species, as did the general appearance and colours. I would have liked to have been able to confirm it genitalically but it proved to be female (I've included a photo of what I assume is the gonocoxa below but as far as I know this isn't relevant for the ID).

female Sepedophilus nigripennis showing fore leg (2 views), elytra, antenna, wings, pronotum and gonocoxa, Wendling Beck Environment Project (Norfolk, UK), 26th September 2025