Temporal range: Late Carboniferous–Permian Like all other
paleodictyopteroids, the megasecopterans had sucking mouthparts.
The suctorial mouth parts were probably used to pierce plant
casings and extract high-quality plant materials, such as spores
and pollen. Unlike some earlier insects, megasecopterans bore
two pairs of wings, which are nearly of the same size. The wings
probably were held horizontally, as in dragonflies (Odonata,
Anisoptera). The wing bases tend to be very slender and
petiolated, as in damselflies (Odonata, Zygoptera). The body was
usually long and thin, although the genus Protohymen was rather
stouter and shorter than a typical megasecopteran. Another
distinctive feature was the presence of a number of fine
processes projecting from the body, which in some cases could be
longer than the body itself, forming long fringes on the
insect's underside. During their relatively brief period of
existence, the Megasecoptera were rather successful. It has been
estimated that this insect order accoun