This Is The Largest Known Insect of All Time, With a Wingspan of 2.5 ft (75 cm)

During the long period griffinflies existed, they actually ruled the air. Flying vertebrates like bats, birds, and pterosaurs would not evolve for at least another 100,000,000 years, so the skies were free of even more active fliers that could have preyed on them.

Of course, this has also contributed to their long existence and, according to some theories, even their body size.