Abstract
Five Cretaceous fossil aphids from Canadian amber are described. All are new species and none is referable to an extant genus. The names assigned to these are as follows: Palaeoaphis archimedia, Ambaraphis costalis, Alloambria caudata, Pseudambria longirostris and Aniferella bostoni. Two new subfamilies have been proposed for four of them and the fifth has been placed in the Neophyllaphidinae, which was previously considered a tribe in the Callaphidinae. One new subfamily, the Palaeoaphidinae, is exceptionally primitive and the two included species, P. archimedia and A. costalis, have more antennal segments and a more primitive wing venation than any known aphid. The cubitus vein in these species is more like that of the Psyllidae and of the extinct Permian Archescytinidae than that of existing Aphidoidea. The venation of the other new subfamily, the Canadaphidinae, shares some similarities with the unipterine aphids that occur on the Combretaceae in Africa.The main features of the evolution of the aphid wing are discussed as an aid in placing the fossils with respect to current concepts of aphid classification.