999 of all living things that have ever existed on earth have gone extinct earth has experienced 5 five extinctions Geologic time scale Era Largest unit of geologic time lasts tens to hundreds of millions of years and consists of two or more periods ID: 781024
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Slide1
The Geologic
Time Scale
Slide2Slide3Mass extinctions
99.9% of all living things that have ever existed on earth have gone extinct earth has experienced 5 five extinctions
Slide4Geologic time scale
Era
Largest unit of geologic time
lasts tens to hundreds of millions of years and consists of two or more periods.
Period
Divides Eras
Most commonly used units of time scale
Lasts millions of years
Each is associated with a particular rock system
Epochs
Divide PeriodsSmallest unit of geologic timeLasts several million years
Slide5Pre Cambrian
Life
Climate/Atmosphere
Bacteria,
sponges
CH4, NH3, H2, C
Volcanic eruptions, lightening
Some areas
freeze
Slide6Paleozoic
ERa
Slide7Cambrian544-505
mya
Life
Climate/Atmosphere
“Cambrian Explosion” = jellyfish, starfish,
worms, sea scorpions
Trilobites dominant
Warm/tropical
No glaciation
Slide8Ordovician505-440
mya
Life
Climate/Atmosphere
Mass extinctions
of marine life
Invertebrates dominant
Starfish, clams, oysters, squids, octopuses
Land
masses gather at south pole
Massive glacier
form
dropping sea levels
Slide9Silurian440-410
mya
Life
Climate/Atmosphere
Earliest
land plants
First
Jawfishes
Trilobites, sea scorpions, mollusks still common
Pangea
forms
Tropical climate
Glaciers melt
Ocean rises
Warm shallow seas form
Slide10Devonian410-360
mya
Life
Climate/Atmosphere
First sharks, amphibians,
insects, and trees
Extinction of armored fish
Very warm
Slide11Carboniferous360-286
mya
Life
Climate/Atmosphere
Amphibians,
winged insects, small reptiles, and conifers and ferns
Warm
tropical areas
Glaciers at poles
Slide12Permian286 – 245
mya
Life
Climate/Atmosphere
Centipedes, spiders, and cockroaches
Seed plants
Reptiles
abundant
Beetles first appear
Many inverts go extinct
Temperatures increase
Sea levels rise
Slide13Mesozoic era
Slide14Triassic245-208
mya
Life
Climate/Atmosphere
Turtles, crocodiles, and
lizards appear
Sharks, sea urchins,
seastars
are abundant
Early dinosaurs
(ex.
placodont
)
Sea levels rise
land is very dry and hot.
glaciers melting.
Slide15Jurassic208-146
mya
Life
Climate/Atmosphere
Insects, sharks, crocodiles, and fish are
abundant
The earliest mammals
appear.
Early
dinosaurs are abundant
Hot
No glaciers
Slide16Cretaceous146-65
mya
Life
Climate/Atmosphere
“Age of
the Dinosaurs”
Flowering plants and bees
Pangea
splits apart creating more coastline
Seasons begin to form
Slide17Cenozoic era
Slide18Tertiary65-1.8
mya
Life
Climate/Atmosphere
“Age of Mammals”
Grasslands, forests, palm
trees, kelp forests
Birds evolve
Started
tropical and then started to cool
Continents crashed into each other creating mountains
Slide19Quarternary
1.8 mya- present
Life
Climate/Atmosphere
First
appearance of woolly mammoth, giant sloth, saber-toothed cats
Went through
an ice age
Temps warmed and continue to
Slide20