"Nature is very efficient at getting rid of its corpses," Olsen told Live Science. After all, certain species or traces of catastrophic events could be missing in the fossil record simply because the sediments may have disappeared over tens of millions of years, Olsen said. About 65 million years ago, a giant asteroid blasted into Earth and formed a giant crater at Chicxulub in the Yucatan Peninsula.īecause the fossil record is incomplete, it's difficult to say exactly what caused the extinctions, or even how rapidly they occurred. At the end of the Triassic period, roughly 201 million years ago, most amphibious creatures and crocodile-like creatures that lived in the tropics were wiped out. The Mesozoic era was bookended by two great extinctions, with another smaller extinction occurring at the end of the Triassic period, Olsen said.Īround 252 million years ago, the end-Permian extinction wiped out most life on Earth over about 60,000 years, according to a February 2014 study in the journal Proceedings of the National Academy of Sciences (PNAS).
Francis Xavier University in Antigonish, Canada. Yet the region still had a belt of tropical rainforest in regions around the equator, said Brendan Murphy, an earth scientist at St. Without much coastline to moderate the continent's interior temperature, Pangaea experienced major temperature swings and was covered in large swaths of desert. During the Triassic period, Pangaea still formed one massive supercontinent. The lush plant life during the Mesozoic era provided plenty of food, allowing the biggest of the dinosaurs, such as the Argentinosaurus, to grow up to 80 tons, according to a 2005 study in the journal Revista del Museo Argentino de Ciencias Naturales.Įarth during the Mesozoic era was much warmer than today, and the planet had no polar ice caps. Flowering plants emerged during the late Cretaceous period. And the Cretaceous period, from 145 million to 66 million years ago is known for its iconic dinosaurs, such as Triceratops , and pterosaurs such as Pteranodon.Ĭoniferous plants, or those that have cone-bearing seeds, already existed at the beginning of the era, but they became much more abundant during the Mesozoic. The Jurassic period, from about 200 million to 145 million years ago, ushered in birds and mammals. The Triassic period, from 252 million to 200 million years ago, saw the rise of reptiles and the first dinosaurs.
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