List of mammals of South America

Caviomorph rodents and monkeys arrived as "waif dispersers" by rafting across the Atlantic from Africa in the Eocene epoch, 35 million or more years ago.

The newcomers out-competed and drove to extinction many mammals that had evolved during South America's long period of isolation, as well as some species from other classes.

[4] South America suffered another major loss of mammal species in the Quaternary extinction event, which started around 12,500 cal BP, at roughly the time of arrival of Paleoindians, and may have lasted up to several thousand years.

[5] While South America currently has no megaherbivore species weighing more than 1000 kg, prior to this event it had a menagerie of about 25 of them (consisting of gomphotheres, camelids, ground sloths, glyptodonts, and toxodontids – 75% of these being "old-timers"), dwarfing Africa's present and recent total of 6.

[6] Anthropogenic climate change and the damage to its ecosystems resulting from the rapid recent growth of the human population pose a further threat to South America's biodiversity.

At the order level, the "old-timers" are overrepresented because of their ancient local origins, while the African immigrants are underrepresented because of their "sweepstakes" mode of dispersal.

The following tags are used to highlight each species' conservation status as assessed by the International Union for Conservation of Nature; those on the left are used here, those in the second column in some other articles: The IUCN status of all listed species except bats was last updated between March and June 2009; bats were updated in September 2009.

At least six families of sparassodonts lived in South America prior to the interchange, dominating the niches for large mammalian carnivores.

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.

All South American monkeys are believed to be descended from ancestors that rafted over from Africa about 25 million years ago in a single dispersal event.

South America's rodent fauna today is largely an outgrowth of two spectacularly fortunate ancient "sweepstakes" dispersal events, each of which was followed by explosive diversification.

Caviomorphs, the first rodents to reach the continent, are believed to have washed ashore after rafting across the Atlantic from Africa over 30 million years ago.

[8] More recently, ancestral sigmodontine rodents[9] apparently island-hopped from Central America 5 million or more years ago,[10][11][12] prior to the formation of the Panamanian land bridge.

Shrews and solenodons closely resemble mice, hedgehogs carry spines, while moles are stout-bodied burrowers.

The diversification of canids and felids in South America was partly a consequence of the inability of the continent's native avian and metatherian predators to compete effectively following the Great American Interchange.

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.