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Home , Hyracotherium, Synthetoceras

1 CHANGES IN DIVERSITY

Summary of Events

2 Order

3 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

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

4 Mammalian Evolution

Overview of Geological Time Scale (Mybp = million years before present)

1) Paleozoic Era Period (~408-360 Mybp) - early in period = vascular plants invade land - diversification of bony fishes - 1st amphibians & insects (move onto land)

Mammalian Evolution

Overview of Geological Time Scale

1) Paleozoic Era Period (~360-286 Mybp) • large forests of vascular plants • 1st seed plants • 1st reptiles (amniote egg) • late in period = 1st internal fertilization

5 Mammalian Evolution

Overview of Geological Time Scale

1) Paleozoic Era Period (~286-248 Mybp) • appearance of subclass Synapsida - synapsids • Order Therapsida (therapsids) = -like reptiles (mammalian grade of anatomical structure) • reptilian adaptive radiation

Order

Synapsid Reptiles

Pelycosaur

Therapsid

6 Mammalian Evolution

Overview of Geological Time Scale

1) Paleozoic Era Permian Period (~286-248 Mybp) • Mass event – largest? • 90+% of marine species extinct • Causes? – glaciation, reduction in ocean volume, volcanoes • Expansion of terrestrial fauna • Pangea formation

Geologic Time Scale

Geologic Time Line Tertiary Period Quaternary

Duration 37 64 78 64.8 1.6 Era: Mesozoic Cenozoic (245-66) (66-0)

7 Mammalian Evolution

Overview of Geological Time Scale

2) Mesozoic Era Triassic Period (~248-213 Mybp) “Dark Age of ” • therapsids declining in numbers; nearly extinct by end of period • 1st dinosaurs • 1st mammals = descendants of remaining therapsids; small body size (<120 mm)

Mammalian Evolution

Overview of Geological Time Scale

2) Mesozoic Era Triassic Period (~248-213 Mybp) • 1st birds • gymnosperms dominate landscape • land masses connected = supercontinent = Pangaea, start dividing late

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

Devonian Carboniferous Permian

Triassic Jurassic

9 Biogeography

Mammalian Evolution

Overview of Geological Time Scale

2) Mesozoic Era Jurassic Period (~213-144 Mybp) • Pangaea divides into Laurasia & Gondwanaland (N-S) • dinosaurs dominate land masses

Mammalian Evolution

Overview of Geological Time Scale

2) Mesozoic Era Jurassic Period (~213-144 Mybp) • archaic mammals; 1st adaptive radiation in mammals (pantotheres, multituberculates, symmetrodonts, triconodonts) • adaptive radiation in birds

10 Geologic Time Scale

Geologic Time Line Tertiary Period Jurassic Cretaceous Quaternary Triassic

Duration 37 64 78 64.8 1.6 Era: Mesozoic Cenozoic (245-66) (66-0)

Mammalian Evolution

Overview of Geological Time Scale

2) Mesozoic Era Cretaceous Period (~144-65 Mybp) • dinosaurs extinct by end of period • Early- (~135 Mybp) – N. America dominate by marsupials, multituberculates & early placentals – opossum-size mammals

Mammalian Evolution

Overview of Geological Time Scale

2) Mesozoic Era Cretaceous Period (~144-65 Mybp) • Early- (~135 Mybp) – angiosperms flourish (magnolias/tulip trees) – insectivore/frugivore dentition – coevolution of flowering plants & mammals (large attractive flowers)

11 Mammalian Evolution

Overview of Geological Time Scale

2) Mesozoic Era Cretaceous Period (~144-65 Mybp) • Early- (~135 Mybp) – trophic specializations & foraging strategies increasing in diversity

Mammalian Evolution

Overview of Geological Time Scale

2) Mesozoic Era Cretaceous Period (~144-65 Mybp) • Mid- (~115-100 Mybp) – western N. Amer. linked to Asia – eastern N. Amer. drifting away from Europe Cretaceous – Africa & India separate from Gondwanaland

Mammalian Evolution

Overview of Geological Time Scale 2) Mesozoic Era Cretaceous Period (~144-65 Mybp) • Mid- (~115-100 Mybp) – Condylarths ( ancestors) & marsupials in "Euramerica"; also in the connected S. Amer. /Antarctica/Australia land mass – Stage set for major independent radiations of mammals during Paleocene

12 CHANGES IN DIVERSITY

Geologic Time Scale

Geologic Time Line Tertiary Period Jurassic Cretaceous Quaternary Triassic

Duration 37 64 78 64.8 1.6 Era: Mesozoic Cenozoic (245-66) (66-0)

Cretaceous

Tertiary

13 Mammalian Evolution

Overview of Geological Time Scale 3) Cenozoic Era Tertiary Period (65-24 Mybp)

• Paleocene Epoch (~65-54 Mybp) – major adaptive radiation of marsupials & placentals; also birds & pollinating insects

– 1st primitive primates & carnivores

Mammalian Evolution Overview of Geological Time Scale 3) Cenozoic Era Tertiary Period (65-24 Mybp) – Paleocene Epoch (~65-54 Mybp) • marsupials move from S. Amer. through unglaciated Antarctica to Australia • marsupials restricted to S. Amer. & Aust. refugia when Antarctica is glaciated

Mammalian Evolution Hyracotherium Overview of Geological Time Scale 3) Cenozoic Era Tertiary Period (65-24 Mybp)

• Epoch (~54-38 Mybp) – modern mammalian orders appear – further increase in mammalian diversity – angiosperm dominance increases

Eohippus

14 Mammalian Evolution

Overview of Geological Time Scale 3) Cenozoic Era Tertiary Period (65-24 Mybp)

• Oligocene Epoch (~38-24 Mybp)

– modern mammalian families appear

– primitive , camels

Mesohippus

Mammalian Evolution

Overview of Geological Time Scale 3) Cenozoic Era Tertiary Period (65-24 Mybp)

• Epoch (~24-5 Mybp)

– modern mammalian subfamilies appear – further mammalian & angiosperm radiation – whales, apes, grazing mammals – spread of grasslands

Overview of Geological Time Scale 3) Cenozoic Era Tertiary Period (65-24 Mybp)

• Epoch (~5-2 Mybp) – modern mammalian genera appear – apelike ancestors of humans appear – land bridge between N. Amer. & S. Amer. forms – large carnivores

15 Geologic Time Scale

Geologic Time Line Tertiary Period Jurassic Cretaceous Quaternary Triassic

Duration 37 64 78 64.8 1.6 Era: Mesozoic Cenozoic (245-66) (66-0)

Overview of Geological Time Scale 3) Cenozoic Era Quaternary Period (~2 Mybp - present)

• Pleistocene Epoch (~2 - 0.01 Mybp) – ice ages – humans appear – large mammal

Ambelodon Pliocene & Pleistocene

Synthetoceras

Pliohippus Teleoceras

Epigalus Amphicyon Agriotherium

16 Camelops

Megatherium

Glyptodon

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 ?

Fires in South American tropical forests

17 Biodiversity Hotspots

Biodiversity Hotspots

Biodiversity Hotspots

18 Biodiversity Hotspots

Biodiversity Hotspots

Biodiversity Hotspots

19 Biodiversity Hotspots

Biodiversity Hotspots

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