Quadruped

Quadrupeds vs. tetrapods

Although the words quadruped and tetrapod are both derived from terms meaning four-footed, they have distinct meanings. A tetrapod is any member of the taxonomic unit Tetrapoda (which is defined by descent from a specific four-limbed ancestor), whereas a quadruped actually uses four limbs for locomotion. Not all tetrapods are quadrupeds and not all quadrupedal animals are tetrapods; some arthropods are adapted for four-footed locomotion, such as the raptorialMantodea, or mantises, and the Nymphalidae, or brush-footed butterflies—the largest butterfly family, with ~6000 species, including the well-known monarch (see photo).