Stenotritus

The Stenotritidae is the smallest of all formally recognised bee families, with only 22 species in two genera, all of them restricted to Australia. Historically, they were generally considered to belong in the family Colletidae, but the stenotritids are presently considered their sister taxon, and deserving of family status. Of prime importance is that the stenotritids have unmodified mouthparts, whereas colletids are separated from all other bees by having bilobed glossae.

The American entomologist Ronald J. McGinley proposed their position as an independent family based on the morphology of the glossae in 1980. This view quickly became established.