Triassic period
Began:Permian mass extinction
248 million years ago
Ended:Triassic-Jurassic mass extinction
205 million years ago
The Triassic began after the worst mass extinction ever, at the end of the Permian. Life on Earth took a while to recover and diversify. The Triassic was characterised by heat, vast deserts and warm seas. Even the polar regions were warm, so lush forests grew there. However, the lack of other life, coupled with the period's particular environmental conditions, opened up some evolutionary opportunities. As a result, the very first mammals and dinosaurs evolved. During this time, the giant supercontinent of Pangaea began to break apart. The period ended as it had begun, with an extinction event that wiped out many species.
what the earth looked like during the triassic period.
Jurassic period
Began:Triassic-Jurassic mass extinction
205 million years ago
Ended:142 million years ago
The Jurassic began after the mass extinction event that ended the Triassic. Life, however, was quick to recover from this blow and the Jurassic eventually became host to the most diverse range of organisms that Earth had yet seen. Amongst them were the first birds and some of the dinosaurs. Continental break-up during this time gave rise to the sea that would eventually widen to become the Atlantic Ocean. The ocean floor that formed at this time is the oldest surviving on the planet - all older ones having now been 'recycled' through plate tectonics.
what the earth looked like in the jurassic period
Cretaceous period
Began:142 million years ago
Ended:Cretaceous-Tertiary mass extinction
65 million years ago
The Cretaceous ended with the most famous mass extinction in history - the one that killed the dinosaurs. Prior to that, it was a warm period with no ice caps at the poles. Much of what we now know as dry land - such as southern England and the midwest of the USA - was underwater, since sea levels reached their highest ever during this time. The Atlantic Ocean grew much wider as North and South America drew apart from Europe and Africa. The Indian Ocean was formed at this time, and the island that was India began its journey north towards Asia.
what the earth looked like during the cretaceous period - virtually the same as today.
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