False ground beetle

Systolosoma
Trachypachus

The false ground beetles are a family (Trachypachidae C. G. Thomson 1857) of beetles that generally resemble small ground beetles, but that are distinguished by the large coxae of their rearmost legs. Only six species are known in the family, with four species of Trachypachus found in northern Eurasia and northern North America, and two species of Systolosoma in Chile.

Their habits are similar to those of the ground beetles; they are usually found in the leaf litter of conifer forests.

To quote G. E. Ball, "the most interesting thing about this small family is its uncertain phylogenetic relationships"; it has been classified as a subfamily of Carabidae, and as a family been placed in several different positions relative to other beetle families.

Reference

• George E. Ball , "Trachypachidae", in Ross H. Arnett, Jr. and Michael C. Thomas, American Beetles (CRC Press, 2001), vol. 1