Geological Periods
Geological
Time Periods are so long ago and cover such vast eras, it is difficult for the
ordinary mortal to quite grasp the immensity of it all. However, most of us will
be familiar with the term Jurassic thanks to the film industry and, avid
followers of the Discovery Channels and other programmes that look back into
the distant past will have no doubt heard about the mass extinction at 65
million years ago when the large dinosaurs were finally doomed. But dont think
that this was the only mass extinction in history. There were others at 505,
438, 360, 248, 213, 144 and 30 million years ago.
To help you try to put
all this into some sort of context and get some sort of idea the time-scales
involved, we have put a table below.
The figures must all be
read as a quantity of Millions Of
Years Ago - MYA.
The events are meant as
a rough guide only (after all not even all the scientists agree on everything)
and for more accurate information further research should be carried out.
Pre-Cambrian 4,600 to 570 MYA
This saw the formation
of the Earth and the Moon at about 4,600 million years ago.
Life is thought to have
begun at about 4,000 million years ago.
The first micro-organisms,
bacteria and blue-green algae appeared about 3,100 million years ago.
The atmosphere became
oxygenated at about 1,900 million years ago.
The first multi-celled
organisms appeared about 1,400 million years ago.
And soft-bodied
creatures were around by about 800 million years ago.
Cambrian 570 to 505
MYA
This period
saw the diversification of life in the sea.
Ordovician 505 to 438
MYA
Sea
creatures continued to flourish.
Silurian 438 to 408
MYA
The end of
this period saw the start of plants on land.
Devonian 408 to 360
MYA
Wingless
insects appeared.
Carboniferous 360 to 286
MYA
Amphibians
and reptiles came to the fore.
Permian 286 to 248
MYA
The
predecessors or Dinosaurs appeared.
Triassic 248 to 208
MYA
Dinosaurs
flourished.
Jurassic 208 to 144
MYA
The first
small mammals were now around and more dinosaurs came along.
Cretaceous 144 to 65
MYA
The first birds
appeared and more dinosaurs flourished. However, at the end of this period, the
large dinosaurs became extinct and mammals were finally able to come out of the
shadows and evolve into dominant creatures on the planet.
Tertiary
Early primates
appeared.
Eocene 55 to 38
MYA
Oligocene
38 to 25 MYA
More and larger
mammals.
Miocene 25 to 5 MYA
Apes and
monkeys appear.
Pliocene
Early men
appear on the scene.
Quaternary
Pleistocene 2 MYA to
10,000 years ago
Enter Modern Man, the Woolly Mammoth & Sabre Toothed Cat
and the start of the Old Stone Age.
Holocene 10, 000
years ago to the present time
See our Historic Periods
page.