Equidae
Equidae (sometimes known as the horse family) is the taxonomic family of horses and related animals, including the extant horses, donkeys, and zebras, and many other species known only from fossils. All extant species are in the genus "Equus". Equidae belongs to the order Perissodactyla, which includes the extant tapirs and rhinoceros, and several extinct families.
Empidoidea
Several species within Empidoidea are of particular interest to ethologists and ecologists, due to elaborate mating rituals and life histories involving freshwater.
The most familiar families in the group are the Empididae and Dolichopodidae, both of which occur worldwide and contain thousands of species. The smaller families were formerly included in the Empididae, but have since been accorded family status. The monophyly of most of these groups have since been confirmed by subsequent studies. The Brachystomatinae and Microphorinae are sometimes elevated to full family status, too, but this would apparently make the Empididae and Dolichopodidae paraphyletic and thus they are retained as subfamilies here. Atelestidae forming the sister group to the rest of Empidoidea is a unanimous result in all studies that have utilized molecular data.