Class Mammalia

1. Class Mammalia Add to online Mammal lecture Reference back to A&P notes beginning of semester

3. Prototheria - Monotremes • 3 extant genera • all live in the Australia-New Zealand region: • Duck-billed platypus (Ornithorhynchus) • Echidna (Tachyglossus) • Long-beaked echidna or spiny anteater (Zaglossus ) • not considered ancestral to therians • specialized surviving sidebranch

4. Monotremes • lay leathery eggs (1 or 2) in underground nests • cloaca • toothless as adults • skeletal differences • have cervical ribs • "reptilian" pelvic girdle • lack a bony housing for the ear

5. Monotremes • young born very altrical • Parental care • platypus - young get milk by sucking/licking the belly hair • echidna – ventral pouch for incubating and 2 suckling regions.

6. Subclass Theria Infraclass Metatheria • Old system - Order Marsupialia • Current – several orders

7. Subclass Theria Infraclass Metatheria • Numerous during Cretaceous (end of Mesozoic) • Southern land masses were united • During Cenozoic • southern masses split, joined northern • Couldn’t compete with placentals.

8. Subclass Theria Infraclass Metatheria • young born tiny, very immature (altricial) • gestation short • time in marsupium > uterus

9. Subclass Theria Infraclass Metatheria • Skeletal differences from eutherians • shape of nasal bone • ancestral dental formulas • presence of epipubic bones • poor thermoregulators

10. Subclass Theria Infraclass Eutheria • Known from late Cretaceous • 18 extant orders

11. Order Xenarthra (Edentata) • most primitive • sloths, anteaters and armadillos (protective armor) • Strong claws • adults few to 0 teeth (molars lack enamel)

12. Order Pholidota • pangolins or scaly anteaters; 7 species • tropical Africa/Asia • Scaly, epidermal layer • curl up for protection

13. Order Pholidota • pangolins or scaly anteaters; 7 species • tropical Africa/Asia • Scaly, epidermal layer • curl up for protection • eats ants and termites • Long tongue, strong digging feet • lack teeth

14. “Edentata clade” • Order Xenarthra (Edentata) • Armadillo and anteater • Order Pholidota – spiny anteater • Similarities considered convergent evolution

15. Stand alone groups • Insectivora • Carnivora

16. Primates • hands that grasp • often opposable thumb (pollex) or big toe (hallux): • well-developed sense of touch • Most have flat finger/toenails

17. Primates • Enlarged brain • Stereoscopic color-vision • Many omnivorous • Most are social

18. Primates • 2 subdivisions

19. Primates • 2 subdivisions • prosimians or lower primates • mostly small, nocturnal • Most rely on smell more than sight or sound • Lemurs, tarsiers ….

20. Primates • The Anthropoids or higher primates • Most larger, diurnal. • Apes • no tails • Larger brain • Larger body • More upright • Fewer offspring, slower to mature • Sight more than smell • Monkeys • nearly all have tails

21. Primates • New World: all monkeys. • Fairly small and exclusively tree dwelling. • Marmosets and tamarins, • squirrel, spider, woolly, and howler monkeys, • Old World: comprise monkeys, apes and humans. • Bigger and spend more time on the ground. • Macaques, Baboons, Mandrills and Drills, Geladas, Mangabeys, Guenons, Leaf-eating monkeys (Langurs, leaf monkeys, colobus, proboscis) (Cercopithecidae)

22. Primates • apes: • Hominidae: • gorillas • chimpanzees and bonobos (aka pygmy chimps), • Humans • Pongidae: orangutan • Hylobatidae: gibbons and siamang

23. Chiroptera • Bats – only flying mammal • Wings – membrane between fingers • Different from birds and pterosaurs

24. Chiroptera • Bats – only flying mammal • Wings – membrane between fingers • Different from birds and pterosaurs • Nocturnal, often forest dweller • Eyesight poor • Well-developed echolocation

25. Chiroptera • Bats – only flying mammal • Wings – membrane between fingers • Different from birds and pterosaurs • Nocturnal, often forest dweller • Eyesight poor • Well-developed echolocation • Related to primates?

26. Dermoptera • flying lemurs or colugos (2 species) • Squirrel size • Gliders • Skin stretched from neck, to forelimbs to backfeet Related to Chiroptera?

27. 1 clade • Primates • Dermoptera (flying lemur) • Tree shrews • Chiroptera • ?

28. Ungulata • Order ARTIODACTYLA (even-toed ungulates eg. pigs, deer & cattle) • Order CETACEA (whales and dolphins) • Order PROBOSCIDEA (elephants) • Order SIRENIA (sea-cows) • Order HYRACOIDEA (hyraxes) • Order PERISSODACTYLA (odd-toed ungulates eg. horses, tapirs and rhinos) • Order TUBULIDENTATA (the aardvark)

29. “Cetartiodactyla “ • Artiodactylids and cetaceans closely related! • Cetaceans evolved from artiodactylids

30. Cetartiodactyla • Artiodactylids and cetaceans closely related! • Cetaceans evolved from artiodactylids • Closely related to hippos, not pigs • Hippos grouped w/ pigs

31. Artiodactyla • 2 or 4-toed • line of symmetry passes between digits 3 & 4 • Ankle structure differs from other ungulates (greater flexibility) • pre-molars different from molars

32. Artiodactyla • Suborder Suina: • pigs, peccaries & hippopotami: • most primitive, regrouped • Suborder Tylopoda: • camels & llamas • Suborder Ruminantia: • cattle, antelopes, deer and giraffes: advanced artiodactyls.

33. Cetacea • Suborder Odontoceti (toothed whales) • Dolphins, killer whales, sperm whale • Suborder Mysticeti (the baleen) whales. • Blue whale, right whales, humpback

34. Proboscidea • elephants - 2 genera, 2 species • Asian African Tusks normally larger, both males & females have

35. Large, communal, herbivores

36. Large, communal, herbivores • Eyes • Small • neck not very flexible

37. Smell • Important • touch with trunk, • move to Jacobson’s organ (roof of mouth)

38. Teeth • Incisors = tusk • Molars – replaced from rear

39. Teeth • Incisors = tusk • Molars – replaced from rear • Hearing and ears • Low frequency communication • Ears – thermoregulation

40. Trunk – very sensitive (tactile) • Respiration (snorkel for aquatic ancestor?) • Hose for water

41. Trunk – very sensitive (tactile) • Respiration (snorkel for aquatic ancestor?) • Hose for water • Chemosensory & tactile

42. Trunk – very sensitive (tactile) • Respiration (snorkel for aquatic ancestor?) • Hose for water • Chemosensory & tactile • Picking up objects • Communication – caress, threat displays, …

43. Closest relative?

44. Closest relative? Sirenia!

45. Sirenia • sea cows, dugongs, manatees (2 genera, 5 species) • Large, slow moving herbivores • Usually solitary

46. Hyracoidea • Hyraxes (3 genera, 11 species) • Africa • rabbit size, rodent-like animals

47. Hyracoidea • Hyraxes (3 genera, 11 species) • Africa • rabbit size, rodent-like animals • 4 toes in front, 3 in rear, hoof-like nails • Rubbery soles – grip rock

48. Hyracoidea • Hyraxes (3 genera, 11 species) • Africa • rabbit size, rodent-like animals • 4 toes in front, 3 in rear, hoof-like nails • Rubbery soles – grip rock • Related to elephants and sirens

49. Perissodactyla • line of symmetry down third digit • a full set of incisors • greatly molarized pre-molars

50. Perissodactyla • line of symmetry down third digit • a full set of incisors • greatly molarized pre-molars • 2 lineages – horses vs. tapirs & rhinos • Replaced by artiodactylids