Archostemata is the smallest of the four suborders of

Coleoptera, with fewer than 50 known living species. It is

an ancient lineage with a rich fossil record dating back at

least to the Triassic, before the age of the dinosaurs, and

living species preserve the simplified appearance of some of

the earliest beetles. Although there are very few species, the

modern fauna has five families, Jurodidae, Micromalthidae,

Crowsoniellidae, Ommatidae, and Cupedidae, but the first

three are each known from only a single living species. Two

of these are among the most mysterious and little-understood

of all insects: Crowsoniellidae was collected only once when

three males were found deep in the soil of Italy in 1973;

Jurodidae are known in the modern fauna from a single

specimen collected in the forests of Sikhote Alin, Russian

Far East. Neither was ever seen again, despite several

expeditions. Other families are better known, but are still

generally rare. Ommatidae, with three genera, Omma,

Beutelius, and Tetraphalerus, is restricted to Australia and

southern South America. Species of Cupedidae, the least rare

of the families, can occasionally be found in all continents

except Europe and Antarctica.

ARCHOSTEMATA

opposite | Tenomerga cinerea (Cupedidae) A typical

member of the ancient family Cupedidae, Tenomerga

cinerea is found, albeit sporadically, in eastern USA

and southern Canada. It has even been observed

on the White House lawn!