Thaumaleidae are a small family of fairly generally small nematocerous flies (1.5­p;7.0 mm) found primarily in the Holarctic Region with some examples from the Southern Hemisphere. Adults of living forms are found in damp areas near the immature stages. Larvae are amphineustic and occur in shaded areas on the vertical surfaces of rocks covered by a thin film of cool, flowing water. They feed on diatoms and other small organic matter.

The fossil record of this family is comprised of a single fossil species from the Jurassic/Cretaceous boundary in eastern Russia.

Ref.: Kovalev (1989b, review and classification of taxa).

MESOTHAUMALEA Kovalev, 1989b: 799 (1990: 121). Type species: Mesothaumalea fossilis Kovalev, 1989, by original designation.
fossilis Kovalev, 1989b: 799 (1990: 122). PA: Russia (Siberia) (Upper Jurassic/ Lower Cretaceous) [C].