Insect Systematics Lecture 5 Order Archeognatha and Zygentoma

The two extant orders of primitively wingless insects, Archaeognatha and Zygentoma, almost certainly are not sister groups, based on most analyses of morphological and molecular data. Thus the traditional grouping of Thysanura sensu lato (meaning in the broad sense, in which the name was first used for apterous insects with “bristletails”) should not be used. Archeogntaha is the oldest order among Class Insecta whereas Zygentoma forms a link with Pterygota by possessing dicondylic articulation