A National Museum of Natural History database for the study of ants , wasps , bees and termites describes the archedictyon as : According to a 1999 scientific paper about the evolution of flght in Palaeozoic Palaeoptera , although the archedictyon of some Palaeodictyoptera have long been believed to be generalized plesiomorphic reticulation from which true cross veins developed through evolution , these may actually be an adaptive feature .
A National Museum of Natural History database for the study of ants , wasps , bees and termites describes the archedictyon as : According to a 1999 paper on the evolution of flght in Palaeoptera the cross veins of some Palaeodictyoptera may be an adaptive feature .
These birds have mandibles with crossed tips , which gives the group its English name .