4. Summary of Events

7. Fossil Record Fossils Most found in marine sedimentary rock
Three requirements:
1) need hard parts, e.g., shell, bone, teeth, wood
2) remains escape destruction after death
3) remains buried rapidly – stop decomposition – minearlization process

8. Fossil Record Fossils Preserved as:
Original soft parts = buried and preserved in permafrost, ice, saturated soils, amber…
Original hard parts = shell, teeth, bones, wood = resist weathering
Altered hard parts = mineralization

9. Mammalian Evolution Overview of Geological Time Scale
(Mybp = million years before present)
1) Paleozoic Era
Devonian Period (~ Mybp)
- early in period = vascular plants invade land
- diversification of bony fishes
- 1st amphibians & insects (move onto land)

10. Mammalian Evolution Overview of Geological Time Scale 1) Paleozoic Era
Carboniferous Period (~ Mybp)
large forests of vascular plants
1st seed plants
1st reptiles (amniote egg)
late in period = 1st internal fertilization

12. Mammalian Evolution Overview of Geological Time Scale 1) Paleozoic Era
Permian Period (~ Mybp)
appearance of subclass Synapsida - synapsids
Order Therapsida (therapsids) = mammal-like reptiles (mammalian grade of anatomical structure)
reptilian adaptive radiation

13. Order

14. Synapsid Reptiles
Pelycosaur
Therapsid

15. Mammalian Evolution Overview of Geological Time Scale 1) Paleozoic Era
Permian Period (~ Mybp)
Mass extinction event – largest?
90+% of marine species extinct
Causes? – glaciation, reduction in ocean volume, volcanoes
Expansion of terrestrial fauna
Pangea formation

17. Geologic Time Scale

18. Mammalian Evolution Overview of Geological Time Scale 2) Mesozoic Era
Triassic Period (~ Mybp)
“Dark Age of Mammals”
therapsids declining in numbers; nearly extinct by end of period
1st dinosaurs
1st mammals = descendants of remaining therapsids; small body size (<120 mm)

19. Mammalian Evolution Overview of Geological Time Scale 2) Mesozoic Era
Triassic Period (~ Mybp)
1st birds
gymnosperms dominate landscape
land masses connected = supercontinent = Pangaea, start dividing late

22. Continental Drift – based on plate tectonics
i.e., continents floating on lithosphere via continually spreading ocean floor

23. Devonian
Carboniferous
Permian
Triassic
Jurassic

24. Biogeography

25. Mammalian Evolution Overview of Geological Time Scale 2) Mesozoic Era
Jurassic Period (~ Mybp)
Pangaea divides into Laurasia & Gondwanaland (N-S)
dinosaurs dominate land masses

26. Mammalian Evolution Overview of Geological Time Scale 2) Mesozoic Era
Jurassic Period (~ Mybp)
archaic mammals; 1st adaptive radiation in mammals (pantotheres, multituberculates, symmetrodonts, triconodonts)
adaptive radiation in birds

27. Geologic Time Scale

28. Mammalian Evolution Overview of Geological Time Scale 2) Mesozoic Era
Cretaceous Period (~ Mybp)
dinosaurs extinct by end of period
Early- (~135 Mybp)
N. America dominate by marsupials, multituberculates & early placentals
opossum-size mammals

29. Mammalian Evolution Overview of Geological Time Scale 2) Mesozoic Era
Cretaceous Period (~ Mybp)
Early- (~135 Mybp)
angiosperms flourish (magnolias/tulip trees)
insectivore/frugivore dentition
coevolution of flowering plants & mammals (large attractive flowers)

30. Mammalian Evolution Overview of Geological Time Scale 2) Mesozoic Era
Cretaceous Period (~ Mybp)
Early- (~135 Mybp)
trophic specializations & foraging strategies increasing in diversity

31. Mammalian Evolution Overview of Geological Time Scale 2) Mesozoic Era
Cretaceous Period (~ Mybp)
Mid- (~ Mybp)
western N. Amer. linked to Asia
eastern N. Amer. drifting away from Europe
Africa & India separate from Gondwanaland
Cretaceous

32. Mammalian Evolution Overview of Geological Time Scale 2) Mesozoic Era
Cretaceous Period (~ Mybp)
Mid- (~ Mybp)
Condylarths (ungulate ancestors) & marsupials in "Euramerica"; also in the connected S. Amer. /Antarctica/Australia land mass
Stage set for major independent radiations of mammals during Paleocene

33. CHANGES IN DIVERSITY

34. Geologic Time Scale

35. Cretaceous
Tertiary

36. Mammalian Evolution Overview of Geological Time Scale 3) Cenozoic Era
Tertiary Period (65-24 Mybp)
Paleocene Epoch (~ Mybp)
major adaptive radiation of marsupials & placentals; also birds & pollinating insects
1st primitive primates & carnivores

37. Mammalian Evolution Overview of Geological Time Scale 3) Cenozoic Era
Tertiary Period ( Mybp)
Paleocene Epoch (~ Mybp)
marsupials move from S. Amer. through unglaciated Antarctica to Australia
marsupials restricted to S. Amer. & Aust. refugia when Antarctica is glaciated

38. Mammalian Evolution Hyracotherium Overview of Geological Time Scale
3) Cenozoic Era
Tertiary Period (65-24 Mybp)
Eocene Epoch (~54-38 Mybp)
modern mammalian orders appear
further increase in mammalian diversity
angiosperm dominance increases
Eohippus

39. Mammalian Evolution Overview of Geological Time Scale 3) Cenozoic Era
Tertiary Period (65-24 Mybp)
Oligocene Epoch (~ Mybp)
modern mammalian families appear
primitive horses, camels
Mesohippus

40. Mammalian Evolution Overview of Geological Time Scale 3) Cenozoic Era
Tertiary Period (65-24 Mybp)
Miocene Epoch (~24-5 Mybp)
modern mammalian subfamilies appear
further mammalian & angiosperm radiation
whales, apes, grazing mammals
spread of grasslands
Merychippus

41. Overview of Geological Time Scale
3) Cenozoic Era
Tertiary Period (65-24 Mybp)
Pliocene Epoch (~5-2 Mybp)
modern mammalian genera appear
apelike ancestors of humans appear
land bridge between N. Amer. & S. Amer. forms
large carnivores

42. Geologic Time Scale

43. Overview of Geological Time Scale
3) Cenozoic Era
Quaternary Period (~2 Mybp - present)
Pleistocene Epoch (~ Mybp)
ice ages
humans appear
large mammal extinctions

44. Pliocene & Pleistocene
Ambelodon
Pliocene & Pleistocene
Synthetoceras
Teleoceras
Pliohippus
Epigalus
Amphicyon
Agriotherium

45. Camelops
Megatherium
Glyptodon

46. Mammalian Evolution Overview of Geological Time Scale 3) Cenozoic Era
Quaternary Period (~2 Mybp present)
Recent Epoch (~0.01 Mybp - present)
historic time
green & industrial revolutions
rapid loss of biodiversity
*Largest extinction event?

47. Fires in
South American
tropical forests

48. Biodiversity Hotspots

49. Biodiversity Hotspots

50. Biodiversity Hotspots

51. Biodiversity Hotspots

52. Biodiversity Hotspots

53. Biodiversity Hotspots

54. Biodiversity Hotspots

55. Biodiversity Hotspots