Transcript Mammalia
Mammals 1 Class Mammalia The name mammalia is derived from mammary glands. These glands produce milk to nourish newborns. Females are the only sex that produce milk, but males also possess these glands. Males just don’t have certain increases of hormones that cause lactation or milk production. 2 Class Mammalia • • • • • • Hair Mammary glands Sweat glands Muscular diaphragm Endothermic Four chambered heart • Two sets of teeth (“baby” and “adult”) • Heterodont teeth – Different shapes and functions 3 Class Mammalia Additional characteristics (you don’t need to write these down) • Movable eyelids • Two occipital condyles • Three ear bones • Placenta – Except two groups 4 Mammals are endothermic. They maintain a constant internal body temperature. Hair and a subcutaneous fatty layer helps to maintain warmth, while sweat glands help cool. 5 Movement • Backbone that flexes vertically and side to side • Variations in limb bones allow walking, running, climbing, burrowing, hopping, swimming, flying, etc. 6 Basic Mammal 7 Lion 8 Rhinoceros 9 Gorilla 10 Chimpanzee 11 Chimp and Human 12 Bat 13 Same bones, different stance 14 Feeding and Digestion • Mammals may be herbivores, carnivores, omnivores, or filter feeders (baleen whale). • They have specialized teeth • Some mammals that eat plant material have specialized organs to break down plant material including a rumen and cecum • The mammalian digestive system cannot break down plant material on its own. Symbioitic relationships with bacteria and fungi allow plant material to be digested in mammalian organs. 15 16 Incissors 17 Canine 18 Premolars 19 Molars 20 Grass eaters have different teeth than carnivores 21 SALIVARY GLANDS • DIGESTION starts in the MOUTH Image from: http://www.entnet.org/healthinfo/throat/salivary.cfm 22 BALEEN Thin keratin plates that hang from the roof of the mouth and screen food from Image from: http://home.iprimus.com.au/readman/whale.htm water 23 24 RUMEN In cud chewers like cows, sheep, goats, giraffes First chamber of stomach containing bacteria to digest plants 25 Image from: http://arbl.cvmbs.colostate.edu/hbooks/pathphys/digestion/herbivores/rumen_anat.html CECUM In non cud chewers like horses, rabbits, rodents, elephants Small pouch off small intestine containing bacteria to digest plants 26 Human Digestive System 27 Respiration • Mammals have a large diaphragm muscle that when contracted, pulls the bottom of the chest cavity downward, increasing the volume of the chest cavity, allowing a mammal to inhale. • Air is pulled into the chest cavity and lungs when this happens. • When the diaphragm muscle relaxes, the volume of the chest cavity decreases and causes air to be pushed out—exhaling. 28 Human Respiratory system 29 Circulatory system • Mammals have a two loop closed system (pulmonary and systemic) that is very efficient at transporting oxygen to cells and removing carbon dioxide from cells. • 4 chambered heart 30 Fig. 31.12 31 Mammal Circulation 32 Excretory system • Mammals have highly developed kidneys that help maintain homeostasis. • Kidneys osmoregulate, maintaining water and ion concentrations, as well as removing excess urea or nitrogenous waste from the blood. 33 Human excretory system 34 Nervous system and response • Mammals have the most highly developed brain of any animal. The three main parts of the mammalian brain are the cerebrum (motor movement, sensory info), cerebellum (balance and coordination), and medulla oblongata (involuntary organ control). • Mammals have a cerebral cortex, the center for thinking and complex behaviors • Mammals have exceptional senses such as smell, hearing, and eyesight. 35 36 Reproduction and development • Distinct separate sexes, sexual reproduction, and internal fertilization. • Most viviparous (duck billed platypus is oviparous and lays eggs) • Young nourished by mother’s milk and usually raised for an extended period of time. 37 38 There are 3 general groups of mammals. Include in notes general characteristics for each as well some common examples. 39 Monotremes • • • • Lay eggs Transitional species Incubate 12 days Lick milk from mothers fur 40 MONOTREMES “Egg laying” Duckbilled Platypus Anteater Echidna 41 Marsupials • Pouched mammals • Birth to tiny embryo that is not fully developed • Embryo crawls into mother’s pouch to complete development 42 MARSUPIALS Premature babies develop in pouch Mostly found in Australia/ New Guinea • Kangaroo • Wallaby 43 MARSUPIALS Only North American Marsupial • Oppossum 44 Placental Mammals • Placenta nourishes embryo inside mother • Long gestation period – 22 months for elephant • Most successful group of mammals 45 PLACENTAL Embryos nourished inside mother by placenta 95% of all mammals are placental At least 18 orders 46 Placental Mammals • Competitive advantage over monotremes and marsupials – Better nutrition from placenta – Less vulnerable to predators • More advanced at birth 47 Evolution of Placenta from Amniotic Egg (you don’t have to write down) Reptile • Mammal • Chorion • Chorion – Oxygen from air • Amnion – Provides private pond • Yolk Sac – Food for embryo • Allantois – Store urinary waste – Form placenta to get oxygen & food from mothers blood • Amnion – Provides private pond • Yolk sac – Temporarily make RBCs • Allantois – Form umbilical cord 48 49 50 Mammal Classification • • • • 14 major orders Over 4,000 species About half are rodents Don’t worry about writing down various order names and groups 51 Order Monotremata • Lays eggs • Young lick milk from mothers fur 52 Order Marsupiallia • Pouch 53 Order Insectivora • • • • Sharp-snout Small Burrow underground Eat insects 54 Order Chiroptera • Flying mammals • Elongated fingers • Echolocation 55 Order Xenarthra • Toothless or peg like teeth 56 Order Carnivora • Large canine teeth • Teeth adapted to shear flesh 57 Order Rodentia • Chisel-like incisor teeth 58 Order Lagomorpha • Four upper incisors • Hind legs adapted for jumping 59 Bats • • • • Only flying mammal Seed dispersal Pollination Control insects 60 Smallest Mammal • Kitti’s hog-nosed Bat • Bumble size • 1.5 grams 61 ECHOLOCATION Bats can fly without eyes, but NOT without ears Bats emit high frequency sound waves that bounce off objects Can determine size, distance, direction, speed 62 Echolocation 63 64 Order Cetacea • Front limbs modified into flippers • No hind limbs • Marine 65 Whales • Blue whale • 100 feet long, 120 tons – 9 story building • Loudest animal– 188 dB • Sound travels 100’s of miles 66 67 Grey Whale 68 Migrates 12,500 miles 69 Grey Whale • 50 feet long • 35 tons • Baleen whale – Sift mud • Endangered species 70 Killer Whale 71 Blue Whale • Baleen whale • Eats krill – Tiny crustaceans – 400 pounds/day • Heart weighs 1000 pounds – Size of a Volkswagen • Endangered species 72 Breaching 73 Killer Whale • 12,000 pounds • Eat fish, squid, seals and whales – 200 pounds/day • Swim 30 mph 74 Humpback Whale 75 Order Pinnipedia • Limbs modified for swimming • Marine carnivores 76 Order Proboscidea • Tusks • Largest living land mammal 77 Order Artiodactyla • Two or four toes 78 Order Perissodactyla • One or three toes 79 Order Primates Write down general characteristics of primates below • • • • Opposable thumb Binocular vision Well developed cerebrum Fingers and toes, fingernails usually • Arms rotate around shoulder joint • Mammary glands reduced to one thoracic pair 80 PRIMATES Larger Brain Grasping hand with fingernails instead of claws 2 forward facing eyes Includes: •Gorillas •Monkeys •Lemurs 81 PRIMATES Humans are primates too! 82 The End 83 References • Content and slides taken from: • Seth Garrison the great • Professor Dennis Anderson at Oklahoma City Community College • Kelly Riedell and her zoology website • Prentice Hall Biology 2002 • McGraw Hill Zoology 2008 84