Swallowtail butterflies are large, colorful butterflies in the family Papilionidae, which includes over 550 species. Though the majority are tropical, members of the family occur on every continent except Antarctica. The family includes the largest butterflies in the world, the birdwing butterflies of the genus Ornithoptera. Swallowtails have a number of characteristic features; for example, on the prothorax a Papilionid caterpillar bears a repugnatorial organ called the osmeterium.
