[2] They are generally quite robust, and consist of many strong-flying forms with relatively long and narrow wings with wrinkled lips shared through their genus.

The western mastiff bat (Eumops perotis), a large species from the southwestern United States and Mexico with wings over 0.5 m (1.6 ft) across, is perhaps one of the best known with this name.

This gives many species a degree of fine tuning in their flight maneuvers to rival their day-flying ecological equivalents, such as swifts, swallows, and martins.

Traits that were previously used to group species, such as having a flat skull, were shown to have no relation to evolutionary relationship, meaning that flat-headedness evolved multiple times within the family.

Of the 16 genera of Molossinae, 15 were used to create the phylogeny (left), with researchers unable to include Peters's flat-headed bat, the only member of Platymops.

Ammerman et al. proposed Molossini (containing Molossus, Eumops, Molossops, Cynomops, Neoplatymops, Nyctinomops, and Promops); Tadarini (containing Tadarida, Chaerephon, Mops, Platymops, Sauromys, Myopterus, and Otomops); Cheiromelini (containing Cheiromeles); and Mormopterini (containing Mormopterus)[2] The 18 genera contain about 100 species: