The following tags are used to highlight each species' conservation status as assessed by the IUCN:
Some species were assessed using an earlier set of criteria. Species assessed using this system have the following instead of near threatened and least concern categories:
The armadillos are small mammals with a bony armored shell. They are native to the Americas. There are around 20 extant species.
The order Pilosa is extant only in the Americas and includes the anteaters, sloths, and tamanduas.
Rodents make up the largest order of mammals, with over 40 percent of mammalian species. They have two incisors in the upper and lower jaw which grow continually and must be keep short by gnawing. Most rodents are small though the capybara can weigh up to 45 kg (100 lb).
The bats' most distinguishing feature is that their forelimbs are developed as wings, making them the only mammals in the world naturally capable of flight. Bat species account for about 20% of all mammals.
The order Cetacea includes whales, dolphins and porpoises. 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.
Carnivorans include over 260 species, the majority of which eat meat as their primary dietary item. They have a characteristic skull shape and dentition.
The even-toed ungulates are ungulates whose weight is borne about equally by the third and fourth toes, rather than mostly or entirely by the third as in perissodactyls. There are about 220 artiodactyl species, including many that are of great economic importance to humans.
Didelphimorphia is the order of common opossums of the Western Hemisphere. 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.