List of mammals of Argentina

Opossums probably diverged from the basic South American marsupials in the late Cretaceous or early Paleocene.

They are small to medium-sized marsupials, about the size of a large house cat, with a long snout and prehensile tail.

Their much larger relatives, the pampatheres and glyptodonts, once lived in North and South America but became extinct following the appearance of humans.

Numerous ground sloths, some of which reached the size of elephants, were once present in both North and South America, as well as on the Antilles, but all went extinct following the arrival of humans.

The bats' most distinguishing feature is that their forelimbs are developed as wings, making them the only mammals capable of flight.

Sequencing of collagen from fossils of one recently extinct species each of notoungulates and litopterns has indicated that these orders comprise a sister group to the perissodactyls.

They are the mammals most fully adapted to aquatic life with a spindle-shaped nearly hairless body, protected by a thick layer of blubber, and forelimbs and tail modified to provide propulsion underwater.