more flexible to enter holes and crawl

through substrates. This has been proposed

as a reason for their extraordinary success.

The other five families of Staphylinoidea are

more typically beetle-shaped, with the elytra

extending to, or nearly to, the tip of the

abdomen, but none of these families reach

even 10 percent of the diversity and species

richness of the Staphylinidae

discovered and named in 1997, despite inhabiting

an entomologically well-studied continent.

Ptiliids are called featherwing beetles because

their wings are reduced to a featherlike strut with

a fringe of bristles, with which they “row” through

the air (which is very dense to such a small animal).

Some travel greater distances by hitchhiking on

birds. Ptiliid reproduction is also modified for small

size, the females producing one egg at a time. For this

reason, they have surprisingly long adult lives of at

least several months.

Hydraenidae are aquatic, and have a strong

superficial resemblance to Hydrophilidae, although

they are usually smaller. They are often found in

brackish water near the coast, even tide pools, where

they feed on algae and organic debris. Agyrtidae are

a very small family, mainly found in the north of the

northern hemisphere and in New Zealand, where

they scavenge on carrion and organic matter.

left | Coelometopon

(Hydraenidae) These

beetles, this one in South

Africa, crawl on rocks

in the spray-zone of

waterfalls grazing algae.

They resemble other water

beetles but are not closely

related to them.

below | Necrophilus pettiti

(Agyrtidae) This North

American primitive

carrion beetle might

resemble Silphidae, but

is actually more closely

related to Leiodidae.