The oldest occurrence of immature Diptera (Insecta), Middle Triassic, France

The oldest fossil Diptera are known from the Gres a Voltzia Formation (Upper Buntsandstein) of the northern Vosges Mountains (northeastern France), the age of which is early Anisian (early Middle Triassic). Six monotypic genera assigned to all the major lineages of Diptera (except for the Culicomorpha) were described from these beds based on adults (Krzeminski et al. 1994; Krzeminski & Krzeminska 2003). Immature Diptera also occur in the Gres A Voltzia (ca 30 specimens). Pupae are abundant whereas the larvae are extremely rare. The most numerous and well-preserved pupal type has been assigned to Voltziapupa n. gen. (V tentata n. sp. and V cornuta n. sp.). These pupae display plesiomorphic characters combined with possibly derived ones. Among the larvae, Anisinodus crinitus n. gen., n. sp. shows culicomorph features. It represents the earliest Culicomorpha (Chironomoidea inc. lam.) known up to date. The other types of dipteran immatures (six pupal and two larval ones) occurring in the Gres a Voltzia are less well preserved, so that their systematic position is difficult to determine and they have been assigned to the Nematocera incertae sedis. These immature Diptera are the first ones recorded from the Triassic.