Download Record of appearance

EARTH’S
HISTORY
Earth Forms
•
4.6 billion years ago
•
Started out as a hot ball of lava
•
As it cooled the crust formed
Oldest piece of
rock ever found
•
4.4 billion years old
•
Found in Australia
•
Zircon crystals
First evidence
of life
•
3.5 billion years ago
•
Prokaryotes: Archaea and bacteria
First fossils of
Algae and
Bacteria
•
Cyanobacteria or “blue green algae”
•
May have formed stromatolites
Free Oxygen in
the atmosphere
•
Cyanobacteria went through a process
called photosynthesis. This is where
carbon dioxide is converted into oxygen
•
21 percent of our atmosphere is made
of oxygen
•
After the appearance of cyanobacteriaapproximately 2.3 billion years ago.
First fossil of
complex
organism
•
Eukaryotic cells
•
1.8 billion years ago
First abundant
life found on
fossil record
•
540 million years ago
•
Cambrian Explosion
•
Major diversification in life forms
appeared
First Fish
•
Jawless fish
•
520 million years ago
First Land
Plants
•
482 million years ago
•
Very simple plants that lacked stems
and roots such as liverworts
First Land
Animals
•
Tetrapods- animals from the sea use
their front legs as crutches to pull
themselves around.
•
360 million years ago
Largest Mass
Extinction
•
250 million years ago
•
90 percent of all species perished
•
May have been due to the volcanism of
the Siberian Traps
First
Dinosaurs
•
230 million years ago
•
They started out small and then grew in
size
Pangea splits
•
175 million years ago
•
The plates began to pull apart
•
This has been a cycle over the last
billion years
First Mammals
•
160 million years ago
•
A shrew like creature
•
Was life hard living with dinosaurs?
First Flowering
Plants
•
140 million years ago
•
Highly diversified (250,000 species) and
they had great success covering more
ground than earlier plants
Dinosaurs go
Extinct
•
65 million years ago
•
The dinosaurs died out along with 50 %
of the other life forms on Earth
•
A meteor impact in the Gulf of Mexico
•
Traces of Iridium are found at a distinct
layer around the world
Mammals and
flowering
plants flourish
•
60 million years ago
•
Mammals begin to grow in size
•
Flowering species diversify even greater
using their mammal friends to carry
seeds to new areas
Beginning of
Cascade
volcanic arc
•
37 million years ago
•
Along the coast of Western coast of
North America
•
The North American plate and the Juan
De Fuca plate slam together at a snails
pace
First primate
in genus Homo
•
2.3 million years ago
First Homo
Sapien
•
100,000 years ago
Human inhabit
North America
•
60,000 years ago
•
Land bridge
End of Last Ice
Age
•
11,700 years ago