Nearctic faunal region The fauna of North America, south to Mexico. At the order and family level the fauna is essentially the same as that of the Palaearctic faunal region, but some genera and more especially species are distinctive to the Nearctic. Because of their strong affinities, the Nearctic and Palaearctic regions are often grouped into one unit, Holarctica, reflecting their former connection via the Bering land bridge.

Nearctic faunal region The fauna of N. America, south to Mexico. At the order and family level the fauna is essentially the same as that of the Palaearctic region, but some genera and more especially species are distinctive to the Nearctic. Because of their strong affinities, the Nearctic and Palaearctic regions are often grouped into one unit, Holarctica, reflecting their former connection via the Bering land bridge.