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Untitled 03 Jul 2009 
Friday   21:43:44 
Untitled Ecosystems
Topics & Issues
Taxonomy
Animals
Birds
Plants
Internet Resources
Regions of the World Untitled
Dinosaurs
Dino Timeline
Types & Classification
Dino Myths & Misconceptions
Museums & Galleries
Dino Quiz
Photogallery & Links Untitled
Navigating Ecosystems
Ecosystems

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Dinosaurs
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Important Biological Events in Earth's History


The table below presents an overview of the major biological events during the earth's geological existence, from "Pre-cambrian" to the "recent time". During the 3.6 billion years, when living organisms were present on earth, the dinosaurs existed only during the Upper Triassic (227 million years ago) to the end of the Upper Creataceous period (about 65 million years ago). [Click on the underlined periods (second column), to explore the types of dinosaurs and the places where they existed, during these time periods.]


Geologic Time Scale

Important Events in
Earth History

Cenozoic Era

 Recent (0.01My) Modern Man spreads worldwide
Neogene
(23.8 My) 		Many mammals vanish
Paleogene
(65 My) 		Modern types of flowering plants appear
Spread and diversification of mammals

Mesozoic Era


Age of Reptiles 		Cretaceous

Upper (98 My)



Lower (144 My)
Dinosaurs and many organisms become extinct.



Flowering plants appear
Jurassic
Upper (159 My)

Middle (180 My)

Lower (205 My)


First birds; dinosaurs increasingly abundant

Triassic
Upper (227 My)

Lower (251 My)

First dinosaurs; first mammals


Abundant cycads and conifers

Paleozoic Era

 Permian
(295 My) 		Extinction of many animals
Carboniferous
(362 My) 		First reptiles; great coal forests; first conifers; first cycads
Devonian
(418 My) 		First amphibians and insects; fishes abundant
Silurian
(439 My) 		First land life (plants and invertebrates)
Ordovician
(490 My) 		First tabulate and rugose corals; first bryozoa
Cambrian
(543 My) 		First record of marine life including trilobites and first vertebrates

Precambrian Era
First living things perhaps 3.6 billion years ago.


To provide some semblance of "time scale", the row height was scaled proportionately to the million years span of each period -- except for "Pre-cambrian" era and "recent time", the "recent time" would be almost a line, while the "Pre-cambrian era would be too high, if properly scaled. Untitled





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      First Written: 19990104       Latest Update: 20060328 Untitled
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