Papilionidae

Papilionidae is a family of butterflies commonly known as swallowtails, comprising more than 550 species found on every continent except Antarctica, most diverse in tropical regions such as Southeast Asia. The family includes the birdwing butterflies, the largest butterflies in the world. Their caterpillars bear a repugnatorial organ on the prothorax called the osmeterium, an eversible forked gland that emits a pungent odor when the larva is threatened. The common name comes from the tail-like extensions on the hindwings of many species, and the family Latin name derives from papilio, meaning butterfly. Species range from sea level to high mountain elevations, with some, such as those in the genus Parnassius, surviving at extreme altitudes.