Mammals Learning Target Objectives:  Distinguish between different groups of mammals, listing examples of each.  Compare and contrast features of organisms that make them unique or help place them in a particular class/group.  Identify body structures (anatomy) and functions (physiology) for each type of mammal.  Differentiate between types of births. Vocabulary: Endotherms * diaphragm * mammary glands * incisors * canines * bicuspids * molars * oviparous * placenta * gestation

Mammals Class: Mammalia (Vertebrates) - evolved from reptiles (therapsids) - endotherms (regulate their body heat – nearly constant) - have hair (insulation) - 4 heart chambers - diaphragm (muscle between chest cavity & abdomen used when breathing) - Mammary glands secrete milk to feed newborns - usually have 4 types of teeth 1) incisors (like our front teeth) 2) canines – pointed teeth 3) bicuspids – 2 points for shearing & shredding (behind canines) 4) molars – flattened teeth for grinding & crushing

Order Monotremata (3 species) - oviparous (lay eggs) - only partially endothermic (body temperature varies more than usual) - nipple-less mammary glands (for platypus) Exs: Duck-billed Platypus, Echidnas (spiny anteaters) Live in Australia, New Guinea, Tazmania Echidnas have a pouch to incubate eggs in. Order Marsupialia: - tiny immature young usually must migrate to a pouch after birth, nipples are here. Exs: opossum, kangaroos, wombats, koalas Most live in Australia

Order Placental: - young are nourished in the uterus by a placenta (formed by the chorion & allantois) Gestation – period of time during which young develop in the uterus Exs: bats, whales, people, rats, rhinos, etc.