Precambrian
|
Archaeozoic
|
5 billion years ago. The Earth's crust
is formed, green algae releases
oxygen into the atmosphere.
|
Proterozoic
|
2.5 billion years ago. Bacteria and
protozoans feed on the algae.
|
Palaeozoic
|
Cambrian
|
570 million years ago. The age of
marine invertebrates, shellfish and
urchins.
|
Ordovician
|
500 million years ago. Primitive fish,
seaweed and fungi emerge.
|
Silurian
|
425 million years ago. Shellfish are
dominant. Fungi have also evolved
into plants on land.
|
Devonian
|
405 million years ago. The Age of
fish prevails. The first true
amphibians form, along with insects
and some small animals.
|
Mississippian
|
345 million years ago. The age of
amphibians begins with shallow seas,
lowlands and fern-covered forests.
|
Pennsylvanian
|
310 million years ago. Warm
climate, swamps, coal forests, the
first reptiles evolve from amphibians.
|
Permian
|
280 million years ago. Coniferous
forests arise, a large number of
marine invertebrates go extinct.
|
Mesozoic
|
Triassic
|
230 million years ago. Active
volcanoes, the age of dinosaurs
begins.
|
Jurassic
|
190 million years ago. Mammals
emerge from small reptiles,
dinosaurs get larger.
|
Cretaceous
|
140 million years ago. The last of the
dinosaurs emerge. Placental
mammals emerge including early
primates.
|
Cenozoic
|
Tertiary
|
65 million years ago. The dinosaurs
are all gone, birds and mammals
take over. Time period divided into
epochs:
|
Palaeocene: 65 million years ago.
Age of small mammals, forests and
deserts paint the continents.
|
Eocene: 54 million years ago. The
dawn of recent life, high sea-levels,
island continents, large herbivores
emerge.
|
Oligocene: 38 million years ago.
Large herbivores dominate, which in
turn begins the emergence of
carnivorous mammals.
|
Miocene: 23 million years ago. The
continents settle as we know them
today. This is the longest epoch in
the Cenozoic.
|
Pliocene: 5 million years ago. The
first apes emerge. This is also the
age most modern mammals we
know today took root.
|
Quarternary
|
Begins 2 million years ago. Modern
days begin. Humans have evolved
from apes in the Pleistocene epoch
(the Ice Age) to today when humans
dominate the Earth.
|
Metazoic
|
Posthomic
|
Believed to be 14 million years
ahead. Humans are extinct, the age
of large mammals begins. Extensive
forests, very large trees, long-lived
fruiting and flowering plants, large,
swift-moving, highly-intelligent
mammals emerge and beat out most
modern mammals.
|
Thermocepian
|
Believed to be 60 million years
ahead. The last of the large, highly
intelligent mammals emerge. Large
continents collide together.
|