Revision of the aberrant New World genus Coenosopsia Diptera: Anthomyiidae, with a discussion of anthomyiid relationships.

. Morphological evidence from the adults males, females corroborates the recent transfer of the problematic New World genus Coenosopsia from the Muscidae to the Anthomyiidae. It is argued that the calyptrate families Anthomyiidae and Muscidae are sister­groups, and that a Neotropical anthomyiid clade, Coenosopsia Malloch + Phaonantho Albuquerque, constitutes the sister-group of the remaining Anthomyiidae. At present, this clade is largely confined to tropical forests of South and Central America, i.e. an environment avoided by practically all other members of this pronouncedly cold-adapted, boreal family. The first, earliest Coenozoic, biotic exchange between North and South America and subsequent biotic isolation are proposed to lie behind the primary dichotomy of the Anthomyiidae. Five species of Coenosopsia, with apparently perfectly allopatric ranges, are recog nized: the Neotropical C.prima Malloch from Ecuador to SE Mexico, C.peruviana sp.n. from Peru, C.brasiliensis sp.n. from Brazil, and C.mexicana sp.n. from SW Mexico, and the Nearctic C.floridensis sp.n. from N Mexico and SE United States. [ABSTRACT FROM AUTHOR]