Chapter 32-2:Diversity of Mammals. Chris Dinh Yonathan Andu Andrew Carpenter. Mammalia. The class Mammalia contains about 4500 species Very diverse 3 groups of living mammals: Monotremes , marsupials, and placentals Groups differ in means of reproduction and development. Monotremes.
There are 12 orders of placental mammals:
Insectivores- insect eaters that have long narrow snouts and sharp claws well suited for digging (shrews, hedgehogs)
Sirenians- herbivores that live in rivers, bays, and warm coastal waters scattered throughout most of the world (manatee)
Cetaceans- adapted to underwater life yet must come to the surface to breathe (whales, dolphins)
Chiropterans- winged mammals, the only mammals capable of flight (bats)
Rodents- single pair of long, curved incisor teeth in both upper and lower jaw, used for gnawing wood and other hard plant material (rats, squirrels)
Perissodactyls- hoofed animals with an odd number of toes on each foot (horses, tapirs, zebras)
Carnivores- stalk or chase their prey by running or pouncing, then kill the prey with sharp teeth (dogs, bears)
Artiodactyls- hoofed mammals that have even number of toes on each foot, mostly consists of large grazing animals (giraffes, camels)
Lagomorphs- herbivores that have two pairs of incisors, one pair on both jaws, and have hind legs adapted for leaping (rabbits)
Xenarthrans- have simple teeth without enamel, some with no teeth at all (sloth, armadillo)
Primates- have highly developed cerebrum and complex behaviors (lemurs, apes)
Proboschideans- Mammals with trunks (elephant)
Earth’s geography helped shape mammals
During Paleozeic Era, the continent was one large landmass where mammals could roam freely
Overtime, after the land separated, unique mammal groups did too
Similar ecological opportunities on the different continents have produced some striking examples of convergent evolution in mammals
Q: About how many species of mammals are their?
A: 4500 species
Q:What are the three groups of mammals?
A: Monotremes, Marsupials, and Placentals
Q: How many orders of Placentals are there?