unidentified Corticaria sp.

I keyed this tentatively to Corticaria serrata but I'm not completely satisfied that this is the correct ID, though I think it probably is. Unfortunately it was a female which means I have no aedeagus to confirm it genitalically. One point in the key that I wasn't completely sure about was how to interpret segment 9 of the antennae. The choice (in Duff) was between "quadrate or slightly elongate, widest at the apex and gradually contracted to the base" and "quadrate or transverse, evenly rounded at the sides." I'd have said it was slightly longer than wide, and therefore "slightly elongate" applied better than "quadrate", but it was clearly rounded at the sides and not widest at the apex. I believe the commonest Corticaria is Corticaria impressa and that's what it would key to if I took the first option, but looking at photos of impressa online, segment 8 really is "widest at the apex and gradually contracted to the base" and not like mine. Corticaria serrata is one of the next most frequently recorded Corticaria in Norfolk but all the records on the NBN Atlas are to the west or south of the county. I'm not hugely far from the nearest record to my west so I don't think it's implausible that I keyed it correctly and it is serrata, but unless someone more experienced with the genus is happy to call it from my photos I'm inclined to leave it unidentified. Annoyingly I can't find any photos of this taken while it was alive - I normally take photos alive so not sure what happened there.

female Corticaria sp. showing pronotum, antenna (2 photos), elytra (from above and side) and sternites, North Elmham (Norfolk, UK), 15th August 2024