Above: Type and only specimen of the pterygote insect Rhyniognatha
hirsti (anterior towards the top) showing the sharp, bladed mandibles (m).
The mandibles are directly comparable to those seen in the pterygote clade
Metapterygota. Rhyniognatha is a relatively derived basal insect,
and may have possessed primitive wings (Engel
& Grimaldi 2004) (scale bar =
200Ám) (Copyright owned
by The Natural History Museum).