What is "megalodontoidea"

The Megalodontoidea are a small superfamily within the Symphyta, containing some 250 living species restricted to the temperate regions of Eurasia and North America. These hymenopterans share the distinctive feature of a very large, almost prognathous head, which is widest ventrally.

A prehistoric family, Xyelydidae, is known from the Jurassic of inner Asia. These animals were even odder-looking than their living relatives. The genus Ferganolyda had bizarre males, with a head half was large and twice as wide as the body and wiry elongated antennae. These features apparently were unsuitable for attack or defense and might have rendered the males effectively flightless.