The Recent world fauna of Sciaroidea, or fungus gnats, comprises approximately 4000 described species in eight families: Bolitophilidae, Cecidomyiidae, Diadocidiidae, Ditomyiidae, Keroplatidae, Lygistorrhinidae, Mycetophilidae, and Sciaridae. Larvae live primarily in decaying vegetation, feeding on fungal mycelia, and they can be among the most abundant insects of temperate forests. Stem-group families appeared in the Jurassic, with large Tertiary deposits being composed almost entirely of living genera, so the Cretaceous is essential for understanding the origins and diversification of Recent families. Sixty-six specimens were studied from six major deposits of Cretaceous amber, spanning 40 million years from the Early to Late Cretaceous: Lebanon (ca. 125 Ma), northern Spain (120 Ma), northern Myanmar (Burma) (ca. 105 Ma), northern Siberia (two sites, 105 and 87 Ma), New Jersey (90 Ma), and western Canada (80 Ma).

New taxa are the following: Docidiadia burmitica (n.gen., n.sp.) (Diadocidiidae); Thereotricha sibirica, (?)T. agapa (n.gen., n.spp.) (Sciaroidea incertae sedis); Archaeognoriste primitiva, Lebanognoriste prima, Plesiognoriste carpenteri, P. zherikhini, Protognoriste amplicauda, P. goeleti, P. nascifoa, Leptognoriste davisi, L. microstoma (n.gen., n.spp.) (Lygistorrhinidae). In Mycetophilidae sensu stricto: Alavamanota burmitina, n.sp. (Manotinae), Neuratelia maimecha, n.sp., Allocotocera burmitica, n.sp., Pseudomanota perplexa, n.gen., n.sp. (Sciophilinae Sciophilini); Apolephthisa bulunensis, n.sp., Synapha longistyla, n.sp., Dziedzickia nashi, n.sp., Saigusaia pikei, n.sp., Syntemna fissurata, n.sp., Gregikia pallida, n.gen., n.sp., Gaalomyia carolinae, n.gen., n.sp. (Sciophilinae Gnoristini); Nedocosia exsanguis, N. sibirica, N. canadensis, N. novacaesarea, n.gen., n.spp.; Ectrepesthoneura succinimontana, E. swolenskyi, n.spp.; Izleiina mirifica, I. spinitibialis, n.gen., n.spp.; Zeliina orientalis, Z. occidentalis, n.gen., n.spp.; Temaleia birmitica, n.gen., n.sp., Lecadonileia parvistyla, n.gen., n.sp.; Disparoleia cristata, n.gen., n.sp.; Hemolia matilei, H. glabra, n.gen., n.spp.; and Protragoneura platycera, n.sp. (Sciophilinae Leiini).

Relationships of the fossil genera are phylogenetically assessed with living genera. The Burmese amber fauna contains an inordinate abundance and diversity of sciaroids, perhaps because of a wetter paleoclimate in that region.