Mammals

POINT > Identify characteristics of mammals POINT > Describe three subclasses of mammals POINT > Describe mammalian teeth POINT > Identify various orders of mammals

POINT > Identify characteristics of mammals Class Mammalia: endothermic vertebrates with fur or hair Infants are fed with milk produced by mother’s mammary glands Have highly specialized teeth Four chambered heart Includes 4000 species: dominant land animals on earth

POINT > Identify characteristics of mammals Two features distinguish them from other vertebrates: Fur or hair Mammary glands

POINT > Identify characteristics of mammals Heart has 4 chambers Diaphragm muscle aids in breathing

What are 4 characteristics of mammals? CHECK: What are 4 characteristics of mammals? Which 2 characteristics are only in mammals? What is the diaphragm?

POINT > Describe three subclasses of mammals 1. Monotremes are egg-laying mammals Only 3 types of monotremes: Duck-billed platypus and two species of spiny anteaters Not completely endothermic (body temperature is lower and changes) Limbs modified for swimming or digging Australia and New Guinea

POINT > Describe three subclasses of mammals Duck-billed platypus: the only poisonous mammal Monotremes Spiny anteater

What is the only poisonous mammal? CHECK: What are monotremes? What is the only poisonous mammal?

POINT > Describe three subclasses of mammals 2. Marsupials: infants stay in mother’s pouch for some time after birth POINT > Describe three subclasses of mammals Short gestation period (time from fertilization to birth) Ex. Koalas, kangaroos, opossums

POINT > Describe three subclasses of mammals Marsupials

What are 2 examples of marsupials? What is gestation period? CHECK: What are marsupials? What are 2 examples of marsupials? What is gestation period?

POINT > Describe three subclasses of mammals 3. Placental mammals: Babies develop more fully inside mother The placenta is the organ that supplies food and oxygen to the embryo, and eliminates wastes The infant is attached to the placenta by the umbilical cord

POINT > Describe three subclasses of mammals 95% of all mammals are placentals Oxygen and nutrients are transferred from mother’s blood to baby’s blood through the placenta

POINT > Describe three subclasses of mammals Gestation period is longer in placental mammals Gestation length is correlated with adult size (bigger mammals have longer gestation periods)

What is the umbilical cord? CHECK: What is the placenta? What is the umbilical cord? Is the gestation period of placental mammals longer or shorter than other mammals? Which would have longer gestation period, a mouse or a horse?

POINT > Describe mammalian teeth Most mammals have 4 different types of teeth: Incisors, canines, premolars, and molars Different types of teeth reflect different diets

POINT > Describe mammalian teeth Different types of teeth reflect different diets

What are 4 types of teeth in mammals? CHECK: What are 4 types of teeth in mammals? Which type of teeth are good for cutting? Which type of teeth are good for grinding?

POINT > Identify various orders of mammals Order Rodentia: Largest mammalian order (over 2,400 species) Includes squirrels, chipmunks, gophers, mice, rats, and porcupines.

POINT > Identify various orders of mammals Order Chiroptera: over 900 species of bats Live throughout the world except in polar environments

POINT > Identify various orders of mammals Order Cetacea: 90 species of whales, dolphins, and porpoises are distributed worldwide Cetaceans have fishlike bodies with forelimbs modified as flippers

POINT > Identify various orders of mammals Order Carnivora: 250 living species in distributed worldwide Most of the species mainly eat meat, which explains the name

POINT > Identify various orders of mammals Order Primates: 200 living species Including lemurs, monkeys, and great apes (including humans)

What are 2 types of rodents? What are 2 types of cetaceans? CHECK: What are 2 types of rodents? What are 2 types of cetaceans? What are 2 types of carnivores? What are 2 types of primates?

Homework: Read 420-428 Complete S.A. page 428 GRAS 174-177