Pointed-keeled Rhyzobius Rhyzobius litura

My first example of this species was spotted on a Broad-leaved Dock.

Pointed-keeled Rhyzobius Rhyzobius litura, North Elmham Cathedral Meadows (Norfolk, UK), 13th June 2021

That was closely followed by this one, swept from the same site. The identification of this one was slightly problematic for me as the literature suggests that the shape of the prosternal keel is the best way to tell it from the scarcer Round-keeled Rhyzobius Rhyzobius chrysomeloides. The overall pale elytra with the U-shape mark the only dark markings, and the habitat (swept from a field away from conifers), made this one much more likely to be litura not chrysomeloides but I was puzzled as the prosternal process seemed to have a more rounded point like chrysomeloides. It was 2.7mm long. I thought it was worth checking with the county recorder for a second opinion and as expected Martin confirmed that it was litura citing the shape of the pronotum as another helpful difference between the two species.

Pointed-keeled Rhyzobius Rhyzobius litura showing prosternal process, North Elmham Cathedral Meadows (Norfolk, UK), 31st June 2021