Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu MAMMALS

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Key Characteristics of Mammals Almost all of today’s large, land-dwelling vertebrates are Mammals are well-adapted for living. They are able to retain water more efficiently than The Mammalian Body

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu The Mammalian Body

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Key Characteristics of Mammals, continued Hair Of all animal species, only mammals have hair. A hair is a composed mainly of dead cells filled with the protein The primary function of hair is. The hair of some mammals helps them blend in with their surroundings. In some mammals, specialized hairs serve a sensory function. The Mammalian Body

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Mammalian Teeth Mammals have only two sets of teeth throughout their lives: baby teeth or teeth, then permanent teeth. Mammals have four kinds of teeth: incisors, canines, premolars, and A mammal’s teeth are for the food it eats. The Mammalian Body

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Like birds, mammals are. They can be active at any time of day or night. They can also live in A mammal must eat about times as much food as an ectotherm of similar size. Mammals have a high metabolic rate and require considerable amounts of The Mammalian Body

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Body Temperature, continued Respiratory System Mammalian are more efficient at obtaining than are reptilian and amphibian lungs. Mammalian lungs contain, small chambers that provide a very large The Mammalian Body

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu The Mammalian Body

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Body Temperature, continued Heart and Circulatory System Mammals have a heart. A septum completely divides the ventricle into two One chamber pumps blood to the body. The other chamber pumps oxygen-poor blood to the lungs. The two kinds of blood do not The Mammalian Body

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu The Mammalian Body

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu The Mammalian Body

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Parental Care Mammals nourish their young with milk. Milk is produced by located on the female’s chest or Young mammals are nourished on milk from birth until, the time when the mother stops nursing them. The Mammalian Body

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Mammals are more diverse in size, anatomy, and than all other Today’s Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Today’s Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Reproduction All mammals reproduce by Mammals are divided into three groups based on differences in how and where the develops. Today’s Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Reproduction, continued Monotremes The monotremes (order ) are the most primitive of all mammals. Among living mammals, only monotremes reproduce by l There are three living monotreme species: the duckbill platypus and two species of Today’s Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Reproduction, continued Marsupials The (order Marsupialia) include kangaroos, koalas, and In marsupial mammals, the young are born incompletely developed. They crawl to their mother’s nipples located in a on her abdomen, then continue their development for several months. Today’s Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Reproduction, continued Placental Mammals The young of placental mammals develop within the female’s uterus. The enables the diffusion of nutrients and oxygen from the mother to the fetus. The period of time between fertilization and birth is called the Most domestic animals (such horses, cattle, dogs, and cats) are Today’s Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Modern Placental Mammals, continued Order 1: Order Rodentia About percent of all mammal species are rodents. Rodents have teeth that are specialized for Most rodents are small in size. Rodents have a rapid rate of Today’s Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Modern Placental Mammals, continued Order 2: Order Chiroptera This order is composed of, the only mammals capable of true flight. Most bats live in groups and are active only Most bats eat insects, using to catch insects while in flight. Today’s Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Modern Placental Mammals, continued Order 3: Order Insectivora This order consists of small mammals, such as the, that eat mainly insects. are the mammals most similar to the ancestors of the placental mammals. Today’s Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Modern Placental Mammals, continued Order 4: Order Carnivora Most species in this order consist of two subgroups: the cat family and the dog family. Carnivores have excellent senses of, vision, and Today’s Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Modern Placental Mammals, continued Order 5: Order This order of marine carnivores includes seals and sea All four limbs of are modified as flippers for swimming. Their bodies are streamlined for rapid movement through the water. Today’s Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Modern Placental Mammals, continued Order 6: Order Primates Humans belong to the order Other members of this order include the prosimians, monkeys, and Most nonhuman primates are Today’s Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Modern Placental Mammals, continued Order 7: Order Artiodactyla Mammals belonging to this order and the following order, Perissodactyla, are, mammals with hooves. Artiodactyls have an even number of toes. Many artiodactyls have a stomach with a storage chamber called a rumen. Mammals with a rumen regurgitate partially digested food, called, rechew it, and swallow it again for further digestion. Today’s Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Modern Placental Mammals, continued Order 8: Order Ungulates with an odd number of toes within their hooves are classified as perissodactyls. This order includes horses, zebras, and rhinoceroses. Perissodactyls lack a and do not chew their Today’s Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Modern Placental Mammals, continued Order 9: Order Cetacea are divided into two groups: the predatory toothed whales, dolphins, and porpoises, and the filter-feeding Today’s Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Modern Placental Mammals, continued Order 10: Order This order is composed of rabbits and hares. Like rodents, lagomorphs have long, continually growing. They also have another pair of incisors that grow behind the first pair. Rabbits and hares have long hind legs and are specialized for Today’s Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Modern Placental Mammals, continued Order 11: Order Sirenia include dugongs and manatees, barrel-shaped marine animals that eat aquatic plants. They have front limbs modified as Sirenians are closely related to elephants and are often called Today’s Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Modern Placental Mammals, continued Order 12: Order Proboscidea There are two living species in this order, the African elephant and the These animals are the land animals alive today. An elephant’s upper incisor teeth are modified into long Today’s Mammals THE END!!!