The first true dipterans known are from the Middle Triassic (around 240 million years ago), and they became widespread during the Middle and Late Triassic. Modern flowering plants did not appear until the Cretaceous (around 140 million years ago), so the original dipterans must have had a different source of nutrition other than nectar. Based on the attraction of many modern fly groups to shiny droplets, it has been suggested that they may have fed on honeydew produced by sap-sucking bugs which were abundant at the time, and dipteran mouthparts are well-adapted to softening and lapping up the crusted residues. The basal clades in the Diptera include the Deuterophlebiidae and the enigmatic Nymphomyiidae. Three episodes of evolutionary radiation are thought to have occurred based on the fossil record. Many new species of lower Diptera developed in the Triassic, about 220 million years ago. Many lower Brachycera appeared in the Jurassic, some 180 million years ago. A third radiation took place among the Schizophora at the start of the Paleogene, 66 million years ago.
the first true dipterans known are from the middle triassic (around 240 million years ago) and they became widespread during the middle and late triassic modern flowering plants did not appear until the cretaceous (around 140 million years ago) so the original dipterans must have had a different source of nutrition other than nectar based on the attraction of many modern fly groups to shiny droplets it has been suggested that they may have fed on honeydew produced by sap-sucking bugs which were abundant at the time and dipteran mouthparts are well-adapted to softening and lapping up the crusted residues the basal clades in the diptera include the deuterophlebiidae and the enigmatic nymphomyiidae three episodes of evolutionary radiation are thought to have occurred based on the fossil record many new species of lower diptera developed in the triassic about 220 million years ago many lower brachycera appeared in the jurassic some 180 million years ago a third radiation took place among the schizophora at the start of the paleogene 66 million years ago