| Where the continents were | Eras | Approximate age (in years) | Subdivision | Approximate duration (in years) | Notes |
Earth, 20 M ago |
CENOZOIC | 10,000 2 M 5 M 24 M 37 M 57 M 66 M |
HOLOCENE PLEISTOCENE PLIOCENE MIOCENE OLIGOCENE EOCENE PALEOCENE |
3 M 19 M 13 M 20 M 9 M |
The beginning of the Eocene was a period when the Earth was very hot, with palm trees and alligators at the north pole. Earth but cooled by the start of the Quaternary. This period relates to today's concern about global warming. Homo sapiens evolved and Ice Ages occures towards the end of this time. The Little Ice Age (which is not a true ice age) occured a few hundred years ago. |
Earth, 190 M ago |
MESOZOIC | 144 M 208 M 245 M |
CRETACEOUS JURASSIC TRIASSIC |
78 M 64 M 37 M |
The Mesozoic is the period in which the dinosaurs lived, and its end was marked by the K-T extinction. This extinction event dramatically changed the Earth's flora and fauna, and its causes are still being investigated by scientists around the world. During the Mesozoic, the giant continent Pangaea broke apart into the continents we have today. |
Earth, 400 M ago |
PALEOZOIC | 286 M 360 M 408 M 438 M 505 M 570 M |
PERMIAN CARBONIFEROUS DEVONIAN SILURIAN ORDOVICIAN CAMBRIAN |
41 M 74 M 48 M 30 M 67 M 65 M |
The Cambrian period, at the beginning of the Paleozoic, was the first time that multicellular life forms florished on Earth. By the end of the Paleozoic, and beginning of the Mesozoic, all the continents of the Earth came together to form the giant continent called PANGAEA and dinosaurs began to roam on land. |
Earth, 540 M ago (end of Precambrian) |
PRECAMBRIAN | 2800 M 4800 M |
PROTEROZOIC ARCHEAN |
2300 M 2000 M |
This period is about 5 times as long as the Paleozoic and Mesozoic combined, a very long time. Less is known about it than the younger time periods. The oldest fossils are of bacteria/archaea dating from 3000 M. The oldest rock is dated at 3800 M. The Earth is thought to be 4600 M years old. |
The Mystery of Mass Extinction is No Longer Murky
Fossil Record Suggests Insect Assaults Foliage May Increase with Warming Globe
Giant Fossil Frog Found in Madagascar
"Frogantuan" - A Podcast about Giant Fossil Frogs
Last modified August 23, 2009 by Jennifer Bergman.
The source of this material is Windows to the Universe, at http://www.windows.ucar.edu/ at the University Corporation for Atmospheric Research (UCAR). © The Regents of the University of Michigan. Windows to the Universe® is a registered trademark of UCAR. All Rights Reserved. Site policies and disclaimer
