Swallowtail butterfly black swallowtail is the state butterfly of Oklahoma. Swallowtail butterfly Swallowtail butterflies are large, colorful butterflies in the family Papilionidae, and include over 550 species. Though the majority are tropical, members of the family inhabit 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 distinctive features; for example, the papilionid caterpillar bears a repugnatorial organ called the osmeterium on its prothorax. The osmeterium normally remains hidden, but when threatened, the larva turns it outward through a transverse dorsal groove by inflating it with fluid.
Comma The serial comma is also known as the Oxford comma, Harvard comma, or series comma. It is sometimes perceived as overly careful or an Americanism, but its usage occurs within both American and British English. It is called the Oxford comma because of its long history of use by Oxford University Press. Opinions among writers and editors differ on whether to use the serial comma. A majority of American style guides mandate use of the serial comma, including "The Chicago Manual of Style", Strunk and White's "The Elements of Style", and the "U.S. Government Printing Office Style Manual". The "AP