Atelestidae
Atelestidae is a family of flies in the superfamily Empidoidea. The four genera were placed in a separate family in 1983; they were formerly either in Platypezidae (which are not even particularly closely related) or considered "incertae sedis". While they are doubtless the most basal of the living Empidoidea, the monophyly of the family is not fully proven. The genus "Nemedina" seems to represent a most ancient lineage among the entire superfamily, while "Meghyperus" is probably not monophyletic in its present delimitation, and it is liable to be split up eventually, with some species being placed elsewhere. In 2010 , the genus "Alavesia", previously only known from Cretaceous fossils, was found alive in Namibia, subsequent species were also described from Brazil. Atelestidae has been shown to form the sister group to the remaining members of the Empidoidea superfamily. Subfamilies include Atelestinae and Nemedininae. Description. Atelestidae are small (2–3 mm) greyish-dusted flies. They are quite similar to Empididae and Ragadidae as all three families have a symmetrical male terminalia without rotation, and the origin of vein R (radial sector) is at a distance from humeral crossvein (h) as long or longer than length of h. However, it is distinguished from  Ragadidae by a costa ending at or near the first and second medial vein (M), and from Empididae by having the prosternum separated from proepisternum. They have a disjunct distribution, being found in both the Holarctic and southern Neotropical regions (Chile). Systematics. Based on the most recent phylogenetic studies, the relationship between Atelestidae and other members of Empidoidea is as follows. The placement of Atelestidae is emphasized in bold formatting.