Meganisoptera
The Meganisoptera were the giant dragonflies from the Palaeozoic era. They lived in the Pennsylvanian (late Carboniferous) epoch to the late Permian period. The group used to be called Protodonata.
The largest of these dragonflies was Meganeuropsis from the early Permian. It had a wingspan of 28 inches (71 cm). Not all this group had giant size, but they were all larger than modern dragonflies.
The modern classification is as follows: