Passive-feeding
Guides
Heptagenioidea
Heptagenioidea is a superfamily of mayflies (Ephemeroptera) distributed across most global regions except the Arctic and Antarctic. The superfamily likely originated in the Jurassic period, coinciding with a shift from still-water to flowing-water breeding habitats. This ecological transition drove rapid radiation and morphological adaptations, including modifications to mouthparts and forelegs for passive feeding in current. Heptageniidae represents the most widely distributed family within this group.