Nalassus laevioctostriatus

I struggled to put a name to this at the time, thinking it was a Carabid, but a couple of years later with a bit more experience under my belt it was much more straightforward. It keyed straightforwardly using Mike Hackson's key. Note the long third segment of the antenna.

Nalassus laevioctostriatus, Lynford (Norfolk, UK), 14th March 2020