All available material of fossil Bibionidae from French Oligocene localities, including the German locality of Kleinkembs right next to the border with France, is revised, and the species redescribed. Several publications (notably Heer 1856, Oustalet 1870 and Théobald 1937) have dealt with this material but there is a large degree of duplication leading to numerous synonyms. In addition, many of the named species have been assigned to the wrong genus. We have found seven species of Penthetria, eleven species of Plecia, seven species of Bibio and a single species of Dilophus in the material of previously named species. Three new species, Penthetria luberonica sp. n., Bibio aquaesextiae sp. n. and Bibiodes provincialis sp. n. are described from French Oligocene localities. The following new combinations are proposed: Penthetria claripennis (Théobald, 1937), Penthetria gigantea (Théobald, 1937), Penthetria graciliventris (Théobald, 1937), Penthetria longiventris (Théobald, 1937), Penthetria nervisinuata (Théobald, 1937), Penthetria subterranea (Théobald, 1937), Plecia morio (Heer, 1849), Bibio major (Oustalet, 1870), Dilophus luteipennis (Théobald, 1937). Many of the species occur from several outcrops, and distinctive faunas can be recognized from Early Oligocene (e.g., Célas and Monteils), Middle Oligocene (e.g., Céreste and Bois d’Asson) and Late Oligocene (e.g. Aix-en-Provence and the German outcrop of Rott). The late Oligocene localities also share some species with the Early Miocene locality of Radoboj, Croatia, but none with the younger locality of Öhningen, Southern Germany. For a number of named species, the type material is poorly preserved and cannot be recognized at the species level, these are commented on and assigned to the lowest taxonomical level to which they can be identified with certainty. The type materials of a number of species appear to be lost; these are placed to genera to the extent that this is possible from the original descriptions and illustrations. Bibio nigripennis Théobald, 1937, nec Brunetti, 1913 is a primary junior homonym and the name must be replaced. The species is moved to the genus Plecia and renamed Plecia theobaldi nom.n.

We describe Cretobibio montsecensis, gen. et sp. nov. based on two female specimens from the Lower Cretaceous of Montsec, Spain. The new genus would key to the subfamily Pleciinae based on the presence of a short vein R2+3 and slender legs. However, some characters suggest an affinity with Bibioninae, notably the weakening of R2+3, the oblique crossvein R-M, crossvein M-Cu connected to M2 rather than the stem of M, and the shortened fore legs. We suggest this species is best considered as representing a new subfamily, Cretobibioninae subfam. nov., as sister group of Bibioninae.

A new fossil genus of Bibionidae (Diptera: Bibionomorpha), Burmahesperinus gen. nov., from the mid-Cretaceous Burmese amber, is described and illustrated (type species Burmahesperinus antennatus sp. nov., the other two species included are B. conicus sp. nov. and B. pedicellatus sp. nov.). The new genus is tentatively placed in a new subfamily, Burmahesperininae subfam. nov. of the family Bibionidae. Its possible phylogenetic position is briefly discussed. The new genus, as well as the subfamily, possesses the wing venation similar to the recent genus Hesperinus Walker, 1848, in combination with Brachycera-like modification of both the male and female antenna and the overall habitus typical of fungus gnats (Sciaroidea).

We revise the available material of fossil Bibionidae from the Oligocene of Germany, except for the Early Oligocene site of Kleinkems which has recently been revised. The bulk of the material originates from the Late Oligocene Lagerstätten of Rott and Enspel. One new species, Bibio castaneipennis sp.n., is described from Enspel. The following new combinations are established: Hesperinus heeri (Heyden & Heyden, 1865) comb.n. (previously Plecia heeri), Plecia dubia (Germar, 1837) (previously Phthiria dubia). Plecia collossea (Heyden & Heyden, 1865) is removed from synonymy with Plecia morio (Heer, 1849), Plecia gracilenta (Heyden & Heyden, 1865) is removed from synonymy with Plecia lygaeoides (Heer, 1849). The following new synonymies are established: Plecia elegantula Meunier, 1915 = Penthetria rottensis Statz, 1943 = Penthetria scita Statz, 1943 = Hesperinus heeri (Heyden & Heyden, 1865); Plecia superba Meunier, 1915 = Plecia imperialis Statz, 1943 = Plecia philippi Statz, 1943 = Plecia collossea (Heyden & Heyden, 1865); Helophilus primarius Germar, 1837 = Plecia abava (Heyden & Heyden, 1865) = Plecia satyrus Statz, 1943 = Plecia dubia (Germar, 1837); Plecia expositia (Heyden & Heyden, 1865) = Plecia grandaeva (Heyden & Heyden, 1865) = Plecia antenata (Heyden & Heyden, 1865) = Plecia elongata (Heyden & Heyden, 1865) = Plecia pulchella Meunier, 1915 = Plecia hypogaea (Heyden & Heyden, 1865); Plecia schineri (Heyden & Heyden, 1865) = Plecia macrocephala (Heyden & Heyden, 1865); Plecia lapidaria (Heyden & Heyden, 1865) = Bibio brachypteroides Meunier, 1915 = Plecia vulpina Statz, 1943 = Plecia pinguis (Heyden & Heyden, 1865); Plecia lapidaria nigra Statz, 1943 = Plecia sluiteri Meunier, 1917; Plecia veterana (Heyden & Heyden, 1865) = Plecia stygia (Heyden & Heyden, 1865); Bibio spadicea Statz, 1943 = Bibio aerosus Statz, 1943; Bibio heydeni Meunier, 1920 = Bibio comosella Statz, 1943 = Bibio germari Meunier, 1920; Plecia heroica Heyden & Heyden, 1865 = Bibio giganteus Unger, 1841; Bibio infumatus Meunier, 1915 = Bibio mimas L. Heyden, 1870. The following names are placed as nomina dubia pending rediscovery of the type material: Plecia volgeri (C.H.G. Heyden, 1859); Bibio janus L. Heyden, 1870; Bibio tertiarius C.H.G. Heyden, 1862; Dilophus deletus (C.H.G. Heyden, 1862). The male morphotypes described but not formally named by Statz (1943) are tentatively assigned to named species.

The Diptera family Bibionidae has a rich fossil record from the Tertiary, however little is known about this family in the Mesozoic. Recently, a number of specimens have been found in mid-Cretaceous Myanmar amber, dating from about 99 MYr BP. I report the finding of the oldest known member of the recent subfamily Bibioninae, as well as the youngest known member of the Cretaceous subfamily Cretobibioninae.The Cretobibioninae is represented by Cretobibio burmiticus sp. n., which suggests a wide, possibly cosmopolitan distribution of the recently discovered subfamily Cretobibionidae, the Bibioninae by Protodilophus semispinosus gen. et sp. n. The latter species is probably related to the recent and Tertiary genus Dilophus, but displays some plesiomorphic traits related to the more recent taxa.