Biogeography deals with the distribution of taxa around the planet in space and time, and the factors influencing this distribution. It includes understanding how modes of dispersal have affected which taxa are cosmopolitan (found worldwide), which are endemic (only found in limited regions), and which have disjunct (widely separated) distributions that may be explained by larger processes such as plate tectonics (changing position of landmasses over geologic time due to shifting of the earth’s plates), landscape and climatic features that provide opportunities and corridors of dispersal, and catastropic changes to an environment, such as volcanic eruptions. Combining the evidence from biogeography and that of genetic relationships among taxa through phylogenetic studies of their “family tree,” scientists are able to make hypotheses about the when, how, and why taxonomic groups are distributed as we find them today or in the fossil record.

In the present time, therevids have been found in all of the biogeographic regions (Afrotropical, Australasian, Nearctic, Neotropical, Palearctic, Oceanian, and Oriental) except the Antarctic. The family is thought to have arisen in the Jurassic when the continents had coalesced into the supercontinent of Pangea, about 200 million years ago. Fossil evidence indicates that both the Therevidae and its sister family, Scenopenidae had already differentiated by the Upper Jurassic. This is consistent with the likely Triassic origin of the Brachycera and rise of other asiloids in the Jurassic (Gaimari and Irwin 2000).

Choose a biogeographic region:



Australasian & Oceanian





It’s too cold in the Antarctic region to support any therevid fauna!

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Relevant Publications

  • Gaimari, S.D. and Irwin, M.E. (2000). Phylogeny, classification, and biogeography of the cycloteline Therevinae (Insecta: Diptera: Therevidae). Zoological Journal of the Linnean Society, 129: 129-240.
  • Grund, M. & Hauser, M. (2005): Pachygaster hymenaea sp. nov. and P. antiqua James,1971 (Diptera: Stratiomyidae) in Neotropical ambers. Zootaxa. 1061: 29–34.
  • Hauser, M. & M. E. Irwin (2005): A new remarkable Xestomyzinae (Insecta, Diptera, Therevidae) genus from Mexican Amber. Zootaxa 1008: 39-45.
  • Hauser, M. & M. E. Irwin (2005): Fossil Therevidae (Insecta: Diptera) from Florissant, Colorado. Journal of Systematic Palaeontology 3(4): 393-401.
  • Hauser, M. & S. L. Winterton (in press): A new fossil genus of small-headed flies (Diptera: Acroceridae: Philopotinae) from Baltic Amber. Annals of the Entomological Society of America