a view of the earth’s past

A View of the EarthA View of the Earth’’s s PastPast

Geologic HistoryGeologic History


Geologic history recorded in layers of rocksGeologic history recorded in layers of rocks Theory of EvolutionTheory of Evolution

Charles Darwin – 1859 – English naturalist (pre-Charles Darwin – 1859 – English naturalist (pre-biologists)biologists)

AKA AKA ““survival of the fittestsurvival of the fittest”” States that organisms change over time and come States that organisms change over time and come

from ancestral types of the same organismsfrom ancestral types of the same organisms Geologic record of fossils supports this theoryGeologic record of fossils supports this theory


Theory of Evolution continuedTheory of Evolution continued Organisms must adapt to their environment or Organisms must adapt to their environment or

else they become extinct (cease to exist on the else they become extinct (cease to exist on the entire planet)entire planet)

Two types of environmental changesTwo types of environmental changes1.1. GeologicGeologic

Dramatic decrease in the amount of water covering Dramatic decrease in the amount of water covering the surfacethe surface

2.2. ClimateClimate Decrease in atmospheric pressure Decrease in atmospheric pressure

Precambrian TimePrecambrian Time Use Use ““timetime”” instead of instead of ““eraera”” because it is so long because it is so long 4.6 billion years to 570 million years ago4.6 billion years to 570 million years ago 88% earth88% earth’’s historys history ShieldsShields – large areas of exposed Precambrian – large areas of exposed Precambrian

rockrock Severely deformed from crustal activity Severely deformed from crustal activity

makes layer of rock hard to distinguishmakes layer of rock hard to distinguish Half deposits of valuable minerals found in Half deposits of valuable minerals found in

these layers (Ni, Fe, Au, Cu)these layers (Ni, Fe, Au, Cu)

Precambrian TimePrecambrian Time

Fossils rareFossils rare Most precambrian life thought to have soft bodies Most precambrian life thought to have soft bodies

– can– can’’t be fossilizedt be fossilized Any hard bodies destroyed by crustal movements Any hard bodies destroyed by crustal movements

of subduction, volcanic activity and erosionof subduction, volcanic activity and erosion Stromatolites – Stromatolites – precambrian fossils – reeflike precambrian fossils – reeflike

depoits made from cyanobacteriadepoits made from cyanobacteria Imprints of marine worms, jellyfish have been Imprints of marine worms, jellyfish have been

found in late precambrian rocks in Austrailiafound in late precambrian rocks in Austrailia

The Paleozoic EraThe Paleozoic Era

570 million to 245 million years ago570 million to 245 million years ago Beginning of era – landmasses covered with Beginning of era – landmasses covered with

waterwater End of era – landmasses collided to form End of era – landmasses collided to form

PangeaPangea

PangeaPangea

The Paleozoic EraThe Paleozoic Era

Abundant fossil recordAbundant fossil record Huge increase in plant and animal lifeHuge increase in plant and animal life So much that era is divided into 7 periodsSo much that era is divided into 7 periods

The Paleozoic Era: Cambrian PeriodThe Paleozoic Era: Cambrian Period

First period of eraFirst period of era Advanced marine life showed upAdvanced marine life showed up

Had hard parts but no backbones Had hard parts but no backbones Quickly replaced precambrian organismsQuickly replaced precambrian organisms Lived in shallow seas that were abundant during Lived in shallow seas that were abundant during

this periodthis period Invertebrates – Invertebrates – animals with no backbonesanimals with no backbones


Most common: TrilobitesMost common: Trilobites Lived on ocean floor Lived on ocean floor

TrilobiteTrilobite


Second most common: BrachiopodsSecond most common: Brachiopods 15 different kinds still exist15 different kinds still exist

BrachipodsBrachipods


Other invertebrates: worms, jellyfish, snails Other invertebrates: worms, jellyfish, snails and spongesand sponges

No land plants or animals foundNo land plants or animals found

The Paleozoic Era: Ordovician The Paleozoic Era: Ordovician PeriodPeriod

Brachiopods increasedBrachiopods increased Trilobites decreasedTrilobites decreased Snails, clams and other mollusks became Snails, clams and other mollusks became

dominant life-formsdominant life-forms Coral appearedCoral appeared GraptolitesGraptolites – tiny invertebrates – appeared – tiny invertebrates – appeared

Useful index fossilsUseful index fossils

graptolitesgraptolites

The Paleozoic Era: Ordovician The Paleozoic Era: Ordovician PeriodPeriod

Ostracoderm - Ostracoderm - First vertebrate – fish covered First vertebrate – fish covered with bony plates but no teeth or jawwith bony plates but no teeth or jaw

Vertebrates – animals with backbonesVertebrates – animals with backbones No plant or animal life on landNo plant or animal life on land

OstracodermOstracoderm

The Paleozoic Era: Silurian PeriodThe Paleozoic Era: Silurian Period

Marine life continued to thrive and evolveMarine life continued to thrive and evolve Echinoderms – Echinoderms – relative of sea star – many relative of sea star – many

during this periodduring this period Eurypterids – Eurypterids – scorpionlike sea creatures – scorpionlike sea creatures –

abundant during this periodabundant during this period Some as long as 2.4 meters found in western New Some as long as 2.4 meters found in western New

YorkYork

EchinodermsEchinoderms

eurypterideurypterid

The Paleozoic Era: Silurian PeriodThe Paleozoic Era: Silurian Period

First land animal such as, spiders and First land animal such as, spiders and millipedes, show up at the end of this periodmillipedes, show up at the end of this period

The Paleozoic Era: Devonian PeriodThe Paleozoic Era: Devonian Period

AGE OF FISHESAGE OF FISHES – many kinds of bony fishes – many kinds of bony fishes

lungfish – lungfish – primitive lungs, could breathe airprimitive lungs, could breathe air

rhipidistiansrhipidistians – also able to breathe air and – also able to breathe air and had strong fins that probably enabled them had strong fins that probably enabled them to crawl out of waterto crawl out of water

Ichthyostega – Ichthyostega – first true amphibianfirst true amphibian

Land plants began to developLand plants began to develop

lungfishlungfish

The Paleozoic Era: The Paleozoic Era: Carboniferous PeriodCarboniferous Period

Meaning “carbon bearing”Meaning “carbon bearing” In North America – divided into 2 sub-periods: In North America – divided into 2 sub-periods:

Mississippian and PennsylvanianMississippian and Pennsylvanian Warm and humid climateWarm and humid climate Many coal deposits in these area came from Many coal deposits in these area came from

this periodthis period

The Paleozoic Era: The Paleozoic Era: Carboniferous PeriodCarboniferous Period

Crinoids – Crinoids – relatives of modern sea starsrelatives of modern sea stars Giant cockroaches and dragonfliesGiant cockroaches and dragonflies Toward end of Pennsylvanian period – first Toward end of Pennsylvanian period – first

land vertebrates appearedland vertebrates appeared Early reptiles resembling large lizardsEarly reptiles resembling large lizards

crinoidscrinoids

The Paleozoic Era:The Paleozoic Era: Permian Period Permian Period

End of Paleozoic era – MASS EXTINCTIONEnd of Paleozoic era – MASS EXTINCTION Pangea almost completely formed from Pangea almost completely formed from

collisions of tectonic platescollisions of tectonic plates Mountains became so high that areas turned Mountains became so high that areas turned

dessert from lack of rain – inland seas evaporateddessert from lack of rain – inland seas evaporated Many marine invertebrates became extinctMany marine invertebrates became extinct Reptiles and amphibians managed to survive this Reptiles and amphibians managed to survive this

extreme climate changeextreme climate change

The Mesozoic EraThe Mesozoic Era

Began 245 million years ago and ended 65 Began 245 million years ago and ended 65 million years agomillion years ago

During this era, climate changes dramaticallyDuring this era, climate changes dramatically Pangea began to break upPangea began to break up Shallow sea marshes covered most of the landShallow sea marshes covered most of the land Continental climates generally warm and Continental climates generally warm and

humidhumid

The Mesozoic EraThe Mesozoic Era

Called the AGE OF REPTILES because favored the survival of reptiles Lizards, turtles, crocodiles, snakes, etc.

http://www.youtube.com/watch?v=SiN0jxZ6I2w

Fossil record – National Geographic – 3Fossil record – National Geographic – 3 ’’ 40 40””

The Mesozoic Era: The Mesozoic Era: Triassic PeriodTriassic Period

AnimalsAnimalsDinosaurs first appeared during this periodDinosaurs first appeared during this period““dinosaur” dinosaur” comes from the Greek word comes from the Greek word meaning “terrible lizard”meaning “terrible lizard”Large variety of sizesLarge variety of sizes

Most in Triassic period were 4-5 m long and Most in Triassic period were 4-5 m long and moved fastmoved fast


PlantsPlantsLush forests of cone-bearing trees Lush forests of cone-bearing trees

Plants that resemble todays palm treesPlants that resemble todays palm trees


Ichthyosaurs – reptilesIchthyosaurs – reptiles Ammonite appeared – marine invertebrateAmmonite appeared – marine invertebrate Earliest mammals appeared – small rodent-like Earliest mammals appeared – small rodent-like

forest creaturesforest creatures

ammoniteammonite

The Mesozoic Era: The Mesozoic Era: Jurassic PeriodJurassic Period

Dinosaurs dominated this periodDinosaurs dominated this period Two major typesTwo major types

1.1. SauischiansSauischians – “lizard-hipped” – herbivores – “lizard-hipped” – herbivores (largest called apatosaur) and carnivores(largest called apatosaur) and carnivores

2.2. OrnithischiansOrnithischians – “bird-hipped” – herbivores – “bird-hipped” – herbivores (stegosaurus)(stegosaurus)

The Mesozoic Era: The Mesozoic Era: Jurassic PeriodJurassic Period

Pterosaur Pterosaur – flying reptiles – had skin over – flying reptiles – had skin over wingswings

ArchaeopteryxArchaeopteryx – first true feathered birds – first true feathered birds

PterosaurPterosaur

ArchaeopteryxArchaeopteryx

The Mesozoic Era: The Mesozoic Era: Cretaceous PeriodCretaceous Period

Dinos continued to dominate EarthDinos continued to dominate Earth Tyrannosaurus rex Tyrannosaurus rex - 6 m tall, huge jaws, razor - 6 m tall, huge jaws, razor

teethteeth Ankylosaurs – dinos covered with bony Ankylosaurs – dinos covered with bony

armorlike plates - herbivoresarmorlike plates - herbivores Ceratopsians – dinos with horns - herbivoresCeratopsians – dinos with horns - herbivores Ornithopods – duck-billed dinos - herbivoresOrnithopods – duck-billed dinos - herbivores

DinosaursDinosaurs http://www.youtube.com/watch?v

=ywQdc_N9_Jo

T-rexT-rex


Many plants showed up Many plants showed up Angiosperms – first flowering plantsAngiosperms – first flowering plants

MagnoliasMagnolias WillowsWillows

Maples, oaks, and walnuts also showed upMaples, oaks, and walnuts also showed up

Angiosperm flowerAngiosperm flower


End of period – MASS EXTINCTION End of period – MASS EXTINCTION including all dinosaursincluding all dinosaurs

Theory 1: 2 mile wide meteor impacted EarthTheory 1: 2 mile wide meteor impacted Earth Theory 2: dramatic climate changes so severe Theory 2: dramatic climate changes so severe

no dinos could surviveno dinos could survive

http://dsc.discovery.com/video-topics/other/dinosaur-videos/the-end-of-the-dinosaurs.htm

The end of the dinosaurs – Discovery – 3’ 30”The end of the dinosaurs – Discovery – 3’ 30”

The Cenozoic EraThe Cenozoic Era

65 million years ago to present day65 million years ago to present day In beginning, continents looked about same as In beginning, continents looked about same as

todaytoday Alps and Himalayas formed in this eraAlps and Himalayas formed in this era Extreme climate changes – like ice agesExtreme climate changes – like ice ages

Various species became extinct and appearedVarious species became extinct and appeared

The Cenozoic EraThe Cenozoic Era

Called the Called the AGE OF MAMMALS AGE OF MAMMALS because because mammals became dominant life-formsmammals became dominant life-forms

Era split into two periods: Tertiary and Era split into two periods: Tertiary and QuaternaryQuaternary Tertiary is divided into 5 Epochs: Paleocene, Tertiary is divided into 5 Epochs: Paleocene,

Eocene, Oligocene, Miocene, and PlioceneEocene, Oligocene, Miocene, and Pliocene Quaternary is divided into 2 Epochs: Pliestocene Quaternary is divided into 2 Epochs: Pliestocene

and Holoceneand Holocene

Tertiary Period: Paleocene and Tertiary Period: Paleocene and Eocene EpochsEocene Epochs

Many mammals evolved – small rodents and Many mammals evolved – small rodents and few carnivoresfew carnivores LemuroidsLemuroids – first primates – first primates HyracotheriumHyracotherium – earliest ancestor of horses – earliest ancestor of horses Flying squirrels, whales, and bats appearedFlying squirrels, whales, and bats appeared Smaller reptiles increased even though dinos were Smaller reptiles increased even though dinos were

completely extinctcompletely extinct

Climate dropped 4Climate dropped 400C worldwide C worldwide

LemuroidsLemuroids

HyracotheriumHyracotherium

Tertiary Period: Oligocene and Tertiary Period: Oligocene and Miocene EpochsMiocene Epochs

Oligocene epoch – climate continued to cool and Oligocene epoch – climate continued to cool and get drierget drierMediterranean Sea dried up – 2,000 m of Mediterranean Sea dried up – 2,000 m of evaporites collected on sea floorevaporites collected on sea floorGrass and cone-bearing plants thrived in Grass and cone-bearing plants thrived in this this climateclimateMany earlier mammals became extinct but Many earlier mammals became extinct but some larger mammals flourishedsome larger mammals flourished

Tertiary Period: Oligocene and Tertiary Period: Oligocene and Miocene EpochsMiocene Epochs

Miocene Epoch – called Miocene Epoch – called Golden Age of Golden Age of MammalsMammalsClimate remained cool and dryClimate remained cool and dryDeer, rhinoceros, and pigsDeer, rhinoceros, and pigs

BaluchitheriumBaluchitherium – rhinoceroslike animal – largest – rhinoceroslike animal – largest known land animal ever existed (2x as large as an known land animal ever existed (2x as large as an elephant)elephant)

Saber-toothed catSaber-toothed cat

BaluchitheriumBaluchitherium

Tertiary Period: Pliocene EpochTertiary Period: Pliocene Epoch

Hunting animals – bear, dog and cats – fully Hunting animals – bear, dog and cats – fully evolvedevolved

First modern horsesFirst modern horses Continental ice sheets began to spreadContinental ice sheets began to spread Bering land bridge appearsBering land bridge appears North and South America connect with a land North and South America connect with a land

bridgebridge

Tertiary Period: Pleistocene and Tertiary Period: Pleistocene and Holocene EpochsHolocene Epochs

Pleistocene EpochPleistocene EpochSeveral periods of glaciation occurred over Eurasia Several periods of glaciation occurred over Eurasia and North Americaand North America

Animals with fur handled coldAnimals with fur handled cold Other animals moved to warmer climatesOther animals moved to warmer climates Animals that didn’t adapt, like giant sloths and dire Animals that didn’t adapt, like giant sloths and dire

wolves, became extinctwolves, became extinct Early ancestors of modern humans foundEarly ancestors of modern humans found

Hunting could have led to extinction of large mammals like Hunting could have led to extinction of large mammals like mammoths mammoths

Tertiary Period: Pleistocene and Tertiary Period: Pleistocene and Holocene Epochs Holocene Epochs

Holocene EpochHolocene Epoch11,000 years ago to present11,000 years ago to presentIce sheets meltedIce sheets meltedCoastlines took shape they are nowCoastlines took shape they are nowHomo sapiensHomo sapiens – modern humans – developed – modern humans – developed agriculture and began to make tools with bronze agriculture and began to make tools with bronze and ironand iron

Homo sapiensHomo sapiens

a view of the earth’s past

Documents

mesozoic era

cambrian period

fromthis period

ordovician period brachiopods

ordovician period ostracoderm

silurian period marine

precambrian life

marine invertebrates