This family of minute (0.5-1.3mm) beetles has 11 species on the 2012 checklist, but a twelfth species (Arthrolips obscura (Sahlberg)) was added in 2013 by Tony Allen and Andrew Duff.  Similar in appearance to the inconspicuous coccinellids, they are mould-feeders and are usually found under fungoid bark or in piles of rotting wood or vegetation, though Orthoperus atomarus (Heer) is synanthropic, occurring in wine cellars on mouldy corks.  Most species are southern in distribution, and identification relies heavily on the elytral microsculpture and genitalia dissections.