Heptagenioidea is a superfamily of
mayflies. Members of this superfamily are found in most parts of the world apart from the Arctic and Antarctic, with
Heptageniidae being the most widely distributed family.
Heptagenioidea probably originated in the
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...
period when mayflies started breeding in flowing water, the mouthparts and forelegs becoming adapted to passive feeding. The ancestors of the new group had bred in still water, and the opportunities provided by the change in environment encouraged rapid radiation.
References
{{Taxonbar, from=Q3133322
Mayflies
Insect superfamilies