The left hindwing appears to be about to form a tail. This may be an expression of an ancestral trait, since tailless birdwings evolved from the ancestor of tailed swallowtails. The tail of Papilionidae is usually an extension of the fourth hindwing vein, and the fact that this individual has such a tail supports this hypothesis. On the other hand, the tail of the Paradisea-species-group is an elongation of the second vein, which is a secondary evolutionary trait among birdwing butterflies. (Yasui)
026-00244
