Summary of Events

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

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

Mammalian Evolution Overview of Geological Time Scale (Mybp = million years before present) 1) Paleozoic Era Devonian 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 Carboniferous Period (~360-286 Mybp) large forests of vascular plants 1st seed plants 1st reptiles (amniote egg) late in period = 1st internal fertilization

Mammalian Evolution Overview of Geological Time Scale 1) Paleozoic Era Permian Period (~286-248 Mybp) appearance of subclass Synapsida - synapsids Order Therapsida (therapsids) = mammal-like reptiles (mammalian grade of anatomical structure) reptilian adaptive radiation

Order

Synapsid Reptiles Pelycosaur Therapsid

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

Geologic Time Scale

Mammalian Evolution Overview of Geological Time Scale 2) Mesozoic Era Triassic Period (~248-213 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)

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

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

Devonian Carboniferous Permian Triassic Jurassic

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

Geologic Time Scale

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)

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 Africa & India separate from Gondwanaland Cretaceous

Mammalian Evolution Overview of Geological Time Scale 2) Mesozoic Era Cretaceous Period (~144-65 Mybp) Mid- (~115-100 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

CHANGES IN DIVERSITY

Geologic Time Scale

Cretaceous Tertiary

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

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 horses, camels Mesohippus

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

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

Geologic Time Scale

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 extinctions

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

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 extinction event?

Fires in South American tropical forests

Biodiversity Hotspots

Biodiversity Hotspots

Biodiversity Hotspots

Biodiversity Hotspots

Biodiversity Hotspots

Biodiversity Hotspots

Biodiversity Hotspots

Biodiversity Hotspots