The superfamily Membracoidea of sap-sucking true-bugs includes two of the largest families within what used to be called the "Homoptera": the leafhoppers (Cicadellidae) and the treehoppers (Membracidae). The other families in this group are quite small, and have, at various points, generally been included as members within other families, though they are all presently considered to be valid, monophyletic groups. The relict family Myerslopiidae is restricted to New Zealand and South America while the Melizoderidae consist of two genera restricted to South America. The great diversity of Neotropical taxa suggests that the group originated in that region.