Phylogenetic Tree of Reptiles

Mammals Class Mammalia Thought to have evolved during the Mesozoic Era from therapsids Mammalian skull accommodates a larger brain relative to body size Chief characteristics and hair and milk-producing mammary glands Infant dependency Internal development Differentiated teeth

Monotremes – (Greek. monos: one + trema: hole) Have a cloaca Mammals - Monotremes Monotremes – (Greek. monos: one + trema: hole) Have a cloaca Egg laying mammals Hard-shelled amniotic eggs Platypus - young lick up milk off of the mother Spiny anteater – young move from egg to a pouch All found in Australia or New Guinea

Mammals - Monotremes 4

Marsupials – (Gk. marsupium: pouch) Females contain pouch Mammals - Marsupials 5 Marsupials – (Gk. marsupium: pouch) Females contain pouch Begin development inside females body and move to pouch; attach to nipples Frequently more babies are born than nipples available Most abundant in Australia and New Guinea, some in South and Central America 1 in North America

6 Mammals - Marsupials

Mammals - Marsupials 7 Tricky tree: DNA bits called retroposons reveal that marsupials share a South American ancestor but form distinct South American and Australian groups.

Flying Squirrel vs Sugar Glider?? Same thing? Sugar gliders are marsupuals; flying squirrels are not? Why do they look and behave so similarly?

Nutrients provided to growing offspring Active life Acute senses Mammals - Placentals 9 Placentals - Females have organ for exchange of maternal and placental blood Nutrients provided to growing offspring Active life Acute senses Brain takes awhile to develop. Why? How long for humans?

Placental Mammals

Major Orders of Mammals Perissodactyla Horses Artiodactyla Deer Carnivora Cats Primates Monkeys Cetacea Whales Chiroptera Bats Rodentia Mice Proboscidea Elephants Lagomorpha Rabbits

Review Chordates Non-vertebrate Chordates Vertebrates Fishes Amphibians Retiles Birds Mammals

Homework: Due Monday (end of class) Homework – Short Term Homework: Due Monday (end of class) anthropoid arboreal bipedalism culture hominid hominoid molecular clock mosaic evolution Primate prosimian

Homework – Long Term Read page 571 Describe at least two examples of how products from animals are used in medicine. For extra credit – find some not listed on this page Read 576 Connecting the Concepts State and support how YOU would measure which group of vertebrates (or invertebrates) are the ‘most successful.’ Make sure you define successful and defend your position.