Flies of the Order Diptera are one of the most successful groups of insects comprising an estimated 120,000 taxonomically valid species found in all areas of the globe except the extreme polar regions and the highest altitudes. They are important economically both as beneficial and pestiferous insects: some are major agricultural pests of crops (e.g., Tephritidae, Agromyzidae), while others are parasites or predators of agriculturally and medically important pests [e.g., Bombyliidae as parasites of tsetse (Glossina)], immature Toxorhynchites mosquitoes (non-biting as adults) predaceous on immatures of biting species of mosquitoes].
Virtually all the extant species of Diptera have been catalogued for all the zoogeographical regions of the world: Afrotropical (Crosskey, ed., 1980); Australasian/ Oceanian (Evenhuis, ed., 1989); Nearctic (Stone et al., 1965); Neotropical (various authors, 1966–1984; e.g., Guimarães, 1967, Robinson, 1970), Oriental (Delfinado & Hardy, eds., 1973, 1975, 1977), and Palearctic (Herting, 1984; Soós & Papp, eds., 1984–1992) [a few families have yet to be catalogueed for the Neotropical and Palearctic regions]. Of these regional catalogues, only the Australasian/Oceanian catalogue fully treats fossil Diptera within its geographical limits (the Afrotropical catalogue lists a few, but not all, of the copal species described by Meunier from that region). No catalogue has been previously compiled, which is devoted exclusively to the fossil Diptera.
Taxonomic research on fossil insects has always been relegated to a subordinate role when compared to that of living species. There are large numbers of undetermined fossil insects including many Diptera lying in many collections throughout the world awaiting descriptions, but only a small fraction of systematic research has ever been devoted to these fossils. Cockerell's (1937) summary statement concerning his dismay at the lack of interest in the study of fossil insects still holds true today:
"It is a singular fact that so many beautifully preserved fossil insects, especially Baltic amber, in the Isle of Wight Oligocene, and in the Oeningen beds, have remained unstudied for decades in the museums of Europe. The students of living insects usually care nothing about them, and will hardly look at them. One would suppose that these remains, throwing so much light on the evolution and migrations of these insects, and therefore of prime importance for the understanding of the modern fauna, would be examined as soon as found, and without delay. That this has not been done seems to show a singular narrowness of mental outlook, resulting partly from ignorance of geology, partly from reluctance to attempt the determination of specimens which do not show all the characters usually required for diagnosis, and perhaps still more from the fact that every worker is confronted by the great mass of living insects, absorbing all his energies. Whatever the explanation, it may truly be said that the collections and study of fossil insects offers an extraordinary opportunity to capable students at the present time."
Fossil insects have been catalogueed on a world basis at various times during the past century. Perhaps the two most well-known efforts toward this end are Scudder (1891) and Handlirsch (1906–1908). Both of these works listed all known fossil insects including those preserved in amber, copal, and various forms of compression fossils. More recently, taxonomic work on amber inclusions (primarily Baltic and Siberian) has led to a series of catalogues of the taxa found in these resins. Of those catalogues, those listing Diptera species in amber and copal include Keilbach (1982) and Spahr (1985, 1989). Lewis (1987, 1989a,b,c,d, 1990a,b,c,d,e, 1992), Lewis et al. (1990a, b,c,d,e), Lewis & Heikes (1991), Lewis & Vasquez (1992), and Swanson & Lewis (1993) have published a series of catalogues and bibliographies dealing with various fossil insects, usually on a regional or temporal basis. Carpenter's (1992) Treatise currently stands as the most important reference to fossil Diptera. It listed many of the families and genera of fossil Diptera, but omitted a few genera and, due to the format of the Treatise series, did not include species-group names except type species of genera. Nevertheless, no catalogues since Handlirsch have compiled all the genera and species of compression fossils of insects on a world basis.
Examples of Diptera are known in the fossil record as long ago as the Upper Triassic (Carnian) of Australia (Evans, 1971; Kovalev, 1983), Japan (Fujiyama, 1991), and the United States (Olsen et al., 1978; Krzeminski, 1992). Rohdendorf (1961, 1962) described Diptera from Issyk-Kul' in Kirghizistan in deposits thought to have been Triassic, but subsequent stratigraphic research has shown that the locality instead dates from the Lower Jurassic (probably Hettangian). It is evident from the existing data that many families of Diptera had become well diversified by the Jurassic and more so during the Cretaceous. It is probable that when more fossil deposits of Triassic age are worked and Diptera are found, the minimum age of many more families will have to be revised.
This catalogue was prepared for two reasons. First, it contains the last set of names of Diptera genus-group and species-group names to be catalogueed and is the last of the regional and temporal cataloguing projects for Diptera. Second, it serves as an essential reference for paleontologists, entomologists, and phylogeneticists. Though previously ignored by some taxonomists, names of fossil taxa come under the same rules of the Code of Zoological Nomenclature (I.C.Z.N., 1985) as other names of animals and thus are fundamentally necessary in dealing with homonymies, synonymies, and the law of priority.
Results of the cataloguing of the fossil Diptera are that 3,125 species in 1,035 described genera are enumerated in this work. Over 5,100 names of fossil Diptera have been proposed including nomina nuda and junior synonyms. In all, 159 families have representative taxa in the fossil record; of these, 49 are extinct. Over 57% of the described species originate from compression fossils. Systematic work on taxa in inclusions in amber is only beginning to realize its full potential and almost 40% of the species listed in this catalogue were described from this preservational type. Of those specimens described from amber, far and away the most (994) were described from Baltic amber. The vast majority of Diptera fossils have been described from the Tertiary (2,448) and in this epoch, the bulk of described fossils (aside from the Baltic amber species) originated from the Oligocene (757).
It is interesting to note that a large amount of Diptera species diversity is exhibited during the Mesozoic. Almost 20% (507) of all fossil Diptera were described from the Jurassic. This may not be as surprising as it might seem at first glance. Ussatchev (1971) mentioned that (at that time) there were 300 undescribed fossil specimens of Asilomorpha (including tabanoids, bombylioids, stratiomyoids, asiloids, and empidoids) known just from the Upper Jurassic (Kimmeridgian) Karatau deposits in Kazakhstan. Since then, much more Jurassic material from the Karatau and other localities has surfaced, and descriptions of new taxa have included many nematocerous Diptera as well as the brachycerous forms.
Work continues on the taxonomic research of fossil Diptera and there is much to be done. Amber inclusions from various regions of the world and from significantly old strata are still being uncovered and provide the most acceptable medium of preservation from which to study ancient and extinct taxa. Compression fossils from the Mesozoic have the potential to provide clues to phylogenetic relationships among certain taxa where the surviving characters (often just wing venation) are enough to identify taxa with confidence (see Donoghue et al., 1989 for a synopsis of the utility of fossils in phylogeny reconstruction). Most of the taxa of Diptera undergoing current systematic research are representatives of families with the largest numbers of specimens being found in fossil and amber deposits. This is primarily true of nematocerous families such as Ceratopogonidae, Limoniidae, and Tipulidae. Other families with large numbers of specimens of fossils in collections awaiting research include Chironomidae, Bibionidae, Sciaridae, Cecidomyiidae, Mycetophilidae, Empididae, Dolichopodidae, and Psychodidae.
In order to present enough essential information to be a useful reference work, yet hold down the number of pages to a reasonable size, this catalogue is of necessity a compromise between a full catalogue with all literature references to names listed and a simple index of taxa of fossil Diptera. All names of fossil Diptera from 1758 to the present are listed in this catalogue with the basic information for reference: taxonomic name, author, reference by date and page, and distribution including type locality, geological horizon, and method of preservation. The cut-off date for taxa listed in the original catalogue was 31 December 1992, though as many names as possible were included for the years 1993–1994.