A Brief History of the
Earth
Timescale
• 7/8 of the entire period life has existed on
earth is known as the Precambrian era.
• During this era, life was largely single celled,
and prokaryotic.
Other Eras
Following the
Precambrian era
came the
Paleozoic,
Mesozoic, &
Cenozoic eras
Cambrian Explosion
• At the beginning of the
Paleozoic era, came the
development of
multicellularity. With
this came an explosion
of diverse life forms,
only a few lines of
these organisms would
survive…
Cambrian species
Animaloracis
Trilobite
Cambrian Organisms contd.
Opabinia
Sidneyia
Our Distant Ancestor
• Pikaia, was the first animal known to
posess a notochord, and is probably the
ancestor to all vertebrates.
Pikaia
Ordovichian
The Giant Orthocone
Sea Scorpions
A Canadian Timeline
• The following scenes represent the same
location of northern Canada, separated
only in time.
Devonian period - 360 million years
Dunkleosteus
Permian period - 280 million years
Jurassic period - 180 million years
Lipleurodon
Cymbospondylus
Jurassic period - 140 million years
Cretaceous period - 107 million
years
Cretaceous period - 75 million
years
Cretaceous period 72 million
years
A VERY Bad Day
Another artist’s rendition of impact
The Survivors
Some early mammals survived the cataclysm.
These would be the ancestors to all living mammals.
Mammals weren't the only survivors, there was of
course….
TROGDOR!
The Burninator
Eocene period - 50 million years
Eocene period - 50 million years
Oligocene - 32 million years
Miocene - 10 million years
Pleistocene - 19,000 years ago