Neotropical faunal region The region which includes S. and Central America, including southern Mexico, the W. Indies, and the Galápagos Islands. Much of the area was isolated for the greater part of the Tertiary Period, which explains the distinctiveness of the fauna and the survival of ancient forms of mammals (e.g. the Marsupialia and Edentata).

Neotropical faunal region The region which includes South and Central America, including southern Mexico, the West Indies, and the Galápagos Islands. Much of the area was isolated for the greater part of the Tertiary Period, which explains the distinctiveness of the fauna and the survival of ancient forms of mammals (e.g. the marsupials and edentates).