EUTHERIAN MAMMALS = PLACENTAL MAMMALS

1. Mammalogy (Fall 2013 Althoff - reference FDVM Chapters 12-20) LEC 04 EUTHERIAN MAMMALS = PLACENTAL MAMMALS

2. Placenta • Organ of ________ between maternal blood & fetal blood • Supplies ___________ to the growing offspring • Wastes passed from offspring to mother for excretion • Advantage: female free to move during pregnancy

3. The PLACENTA – the most advanced “support” structure for development

4. Insectivora Chiroptera Lagomorpha Rodentia Carnivora Perissodactyla Artiodactyla Cetacea Primates Major Orders(taxonomically speaking)

5. ORDER: Insectivora • Moles & shrews • Primitive (____________) • Small in size • _______________ teeth • Descendants of ____________ eutherian mammals

6. Insectivora • Eranacediae: hedgehogs, --largest form of all insectivores --none in North America • Talpidae: moles --fossorial (locomotion/life style) --eye & eye lie __________ skin --essentially lacking pinnae --good _______, ________ senses

7. Insectivora...continued star nosed mole Condyluracristata • Talpidae...continued --fur velvet-like, ____________ --food: ______ animal --high metabolic rate (______ of body wt. consumed daily)

8. Insectivora...continued • Sorcidae--shrews (“shrew-mice”) --most “___________” of all insectivores (241+ species) --live in ___________ --_________ living mammal is Sorexhoyi...pigmy shrew (3 g, 35 mm head-to-base-of-tail)

9. Insectivora...continued • Sorcidae...continued --_____ eyes --excellent __________sense --high metabolic rate: eats 50-100% of body weight daily --short tails, some poisonous (ex. short-tailed shrew)

10. Insectivora...continued • Sorcidae...continued --no _____________Subfamily Soricinae has reddish (or blackish) __________ teethdue to presence of iron

11. ORDER: Dermoptera • Flying lemurs = colugos • Only 2 species • ____________ • Furred membrane starts at back of ear, connects limbs, ends at tail • Closely-related to ________ __________ …not rodents

12. ORDER: Dermoptera con’t • Flying lemurs = colugos • These are ____ true lemurs (that would be the order Primate) • Omnivores: fruits & insects • Dermoptera translates to “_______________”

13. ORDER: Chiroptera • Bats • Digits support ___________ wings • Only true “flying” mammals (others glide)…often the only _______________ __________ Little brown bat Long-eared bat

14. Chiroptera • Chiroptera = “__________” • Extra _______ between digits • Adapted to foraging for insects via flying...avoided competition with birds by _______________ • 3rd & 4th digits--skin, to hind foot

15. Bat wing skeleton = hand wing ________ “hand” bones: M1-M5 = metacarpels PH I –V = phlanges Plus, radius elongated _______________ bones: reduced = ulna fused = carpals

16. Chiroptera...continued • _____chiroptera vs. ______chiroptera ....key difference: _____________

17. Megachiroptera • No echolocation • 1st & 2nd finger (digit) free of membrane • _____ larger • __________ • Diurnal ghost-faced bat

18. Microchiroptera • Echolocation: tragus “_____” into pinnae • 2nd & 3rd digits fused • Smaller • ________________ • Nocturnal

19. Chiroptera...continued • Five families (16 total): --Noctilionidae: “bull-dog bats” feed on fish --Phyllostomidae: “leaf-nosed” --___________________________ --Desmondontidae: Vampire bats (sometimes grouped with Phyllostomidae) --Molossidae: Free-tailed bats

20. ORDER: Xenarthra • Formerly “Edentata” --_________ teeth • Sloths, anteaters, armadillos • Sloths--arboreal • Anteaters--__________, terrestrial • Armadillos--jointed armor (bony ________ covered by _______ __________) • all are or tend to be “________________”

21. Xenarthra…con’t • Nine-banded armadillo (Dasypus novemicinctus) only representative in North America • Low metabolic rates (see Fig. 15.1, p303) • Low body temperature 34 C (93 F) vs 36-38 C for other mammals…thus _______________ _________

22. ORDER: Pholidota • Scaly anteaters (pangolins) • No teeth--all are or tend to be “myrmecophagous” • Scales composed of ____________ hair (see Fig. 15.13, p310) (i.e. scales) • Sense-wise, very comparable to _______: poor vision & hearing but eject an unpleasant smelling secretion from the anal glands • Africa & Asia

23. ORDERS: Tubulidentata • Aardvark (“_________”) • Only ____ species in this order making it the _________ eutherian order • “myrmecophagous” but unusual dentition with pulp tubules (see Fig. 14.11c, p245) • Eaten by natives who also make jewelry & good luck charms from their teeth

24. Aardvark – pulp tubules “surrounded by dentine” Pulp tubule dentine Accounts for order name: “tubule-toothed” Teeth: open rooted, without enamel, and covered with cementum. Also muscular __________ of stomach more grinding!

25. ORDER: Lagomorpha • Rabbits, hares, pikas • _____ teeth • Chisel-like incisors, hind legs longer than forelegs (usually) • Chewing motion: ____________ • Masseter muscle: ____________ • Rabbits & hares: long ears for __________________

26. Lagomorphs • Two families: Ochotonidae: Pikas Leporidae: Rabbits & hares

27. Pikas: Ochotonidae • Short-legged, short earred • No tail • Front & hind legs about same length • Northern temperate & mountains • Adapted to high altitude • Cut, cure, & store grass

28. Pikas

29. Rabbits & Hares: LeporidaeCharacteristicsHaresRabbitsinterparietal young gestation (days) burrow use (in North America) Note: hares in NA include snowshoe hare andjackrabbits

30. Leporidae...continued • Mode of nutrition like rodents with ____________ (coprophagy) ...______ fecal pellets are __________. • Adaptation to deal with ________. The caecum houses ________--yeast capable of breaking down _________. • Caecum is ______absorptive portion of intestines

32. ORDER: Rodentia • Mice, rats, squirrels, beaver, porcupines • Incisor teeth grow continuously, rootless • Large diastema (no canines) • Chewing motion: rotary • Masseter muscle: complex • Molar occlusal surfaces varied (see Fig. 18.2, p349)

35. Rodentia • ___________ ORDER among mammals (_______ of mammalian species) • 2016 recognized species • ___________ in New Zealand & Antarctica • Great diversity, great popn sizes .… strongly influences on ___________ through systems • Diverse array of ________________: plantigrade, cursorial, swimming, fossorial, jumping, and gliding

36. Rodentia…con’t 3 basic groupings: • Sciuromorph - squirrel-shaped • Myomorph - mouse-shaped • Hystricomorph - porcupine-shaped More important for understanding anatomical relationships than systematic relationships

37. C A B A Figure 18.1 A B C

38. Rodentia...continued Success attributed to: 1) ____________ --occupy microhabitats 2) consume “_______” food sources 3) _________________ --response to favorable conditions & rapid evolution

39. Rodentia...continued • Masseter Muscle: highly developed, anterior-posterior movement size of _________________and passage through it. Also see view in text (Fig. 18.3, p350) • 16 to 22 teeth

40. Myomorph (mouse-shaped) masseter muscle (m.m.) complex • Modest infraorbital foramen • “deep” portion of m.m. passing through • infraorbital foramen and originating on • rostrum

41. Rodentia...families • Aplodontidae: mt. beaver,in Pacific NW, most primitive of mammals • Sciuridae: squirrels, prairie dogs, chipmunks, marmots • Geomyidae: pocket gophers, NA only: fossorial, tunnels

42. Rodentia...families • Heteromyridae:kangaroo rats, pocket mice; NA only; saltatorial = “jumping”; live off of ___________ water--have incredibly long loop of the nephron (result: urine up to _____ that of plasma concentration) • Castoridae: beavers

43. Rodentia...Families Muridae(superfamily: Muroidea)(see Table 18.1, p357) 2 key subfamilies: Sigmodontinae: Peromyscus spp.; Arvicolinae (Microtines): Microtus spp.,

44. Old vs. New World Murids • Murinae is the subfamily • house mouse (Mus musculus) & Norway rat (Rattus novegicus) --two commensal rodents (commensal in this case with humans !) • _____ World rats & mice, intro. to NA vs. Peromyscus & Microtus are referred to as _____ World mice

45. Other Sciurognath Rodents... • Dipodidae: jumping mice (Zapus spp.) • Anomaluridae: scaly-tailed flying squirrels (found in West and Central Africa) (see Fig. 18.13, p356)…close resemblance to sciurid flying squirrels due to convergence…not phylogenetic relationship

46. Hystricognath Rodents... • Erethizontidae: New World porcupines--quill tips _____ barbed • Hystricidae: Old World porcupines--quills _____ barbed • Cavidae: guinea pigs, cavies, and Patagonian hares (see Fig. 18.21, p362); SA; widely distributed; guinea pigs are rare in the wild

47. Hystricognath Rodents... Hydrochaeridae:Capybara; ______ of all living rodents(> 100 lbs.) Chincillidae: chinchillas Myocastridae: nutria; __________ to NA from SA (easily mistake for muskrat…but tail is sparsely furred) Bathergidae: mole rats; highly fossorial (tunnels up to 300 m)

48. Rodentia...Chewing • _____________ teeth a) ever-growing incisors (all families); enamel anterior sideb) ever-growing cheek teeth (Geomyidae, Heteromyidae, Microtinae) • Diastema _______________

49. Rodentia...Diastema • Adaptation of ______________ mammals • Herbivores subject to predation during feeding • Two-chambered oral cavity a) ________ (some with cheek pouches) b) ________--1st “breakdown” effort with grasses, forbs, woody veg.

50. ORDER: Carnivora • Dogs, bears, cats, sea lions • Phylogeny “interesting” (see Fig. 16.1, p315) ; 2 suborders • Unique social communication systems & behavior