Simplify the following text for a Grade 8 native English-speaking person.
Original: The ( Eastern ) Black Swallowtail ( Papilio polyxenes ) also called the American Swallowtail or Parsnip Swallowtail , is a butterfly found throughout much of North America .
Simplified: The Black Swallowtail ( Papilio polyxenes ) is a species of butterfly . It is also called the American Swallowtail or Parsnip Swallowtail .