FIGURE 1. Main features of the phylogenies suggested by Tillyard (1917), Fraser (1957), Carle (1982a) and Bechly (1996). Only the superfamilies are shown and some detail is inevitably lost in these diagrams which do not show the changing composition of some smaller superfamilies or the placement of minor families. For example, anisopteran families Cordulegastridae and Chlorogomphidae have been variously placed in Gomphoidea or Aeshnoidea or Libeluloidea and the scope of zygopteran superfamily Megapodagrionoidea varies greatly among authors. Paraphyletic superfamilies are indicated as multiple lineages. Abbreviations Coen: Coenagrionoidea, Lest: Lestoidea, Hemi: Hemiphlebia, Cal: Calopterygoidea, Epio: Epiophlebia, Gomph: Gomphoidea, Petal: Petaluridae, Aesh: Aeshnoidea, Libel: Libelluloidea.