The relict family Apsilocephalidae was formed in 1991 for three extant species, two species of Clesthentia (=Clesthentiella) from Tasmania and Apsilocephala longistyla from North America, with another extant species, Kaurimyia thorpei, described in 2008 from New Zealand. Extinct fossil Apsilocephalidae species have been described from mid-Cretaceous Burmese amber, Eocene Florissant shale (North America), and Eocene Baltic amber.
References
Nagatomi, A., Saigusa, T., Nagatomi, H. & Lyneborg, L. 1991. Apsilocephalidae, a new family of the orthorrhaphous Brachycera (Insecta, Diptera). Zoological Science 8: 579–591.
Solórzano Kraemer, M. M., & Cumming, J. M. 2019. New genera of brachyceran flies (Diptera: Xylomyidae and Apsilocephalidae sensu auctorum) from mid-Cretaceous Hukawng Valley Burmese amber. Palaeoentomology 002 (3): 251–261.
White, A. 1914. The Diptera-Brachycera of Tasmania. Part I. Families Leptidae, Stratiomyidae, Nemestrinidae, & Cyrtidae. Papers and Proceedings of the Royal Society of Tasmania 1914: 35-74.
Winterton, S. & Irwin, M. E. 2008. Kaurimyia gen. nov.: discovery of Apsilocephalidae (Diptera: therevoid clade) in New Zealand. Zootaxa 1779: 38–44.