Over the past 450 million years, life on earth has undergone at least five great extinctions, when biological activity nosedived and dominant groups of creatures disappeared. The final one (so far) was 65 million years ago, when it appears that a giant meteorite brought fires, shock waves and tsunamis, then drastically altered the climate. That killed off [...]
The Fourth ExtinctionThe Rise of Dinosaurs—and the Age of Humans
Researchers at Lamont-Doherty Earth Observatory are investigating why life on earth was nearly extinguished 200 million years ago—and whether that event holds relevance for today.
Wave-washed sea cliffs along the coasts of western England and Wales are home to spectacular assemblages of rocks and fossils that may hold keys to understanding a sudden global extinction 201.4 million years ago that cleared the way for the rapid evolution of dinosaurs. Paleontologist Paul Olsen and geologist Dennis Kent of Columbia University’s Lamont-Doherty [...]
Paleontologist Paul Olsen has been investigating the causes of Triassic-Jurassic extinction–a turning point in earth’s history that wiped out many life forms and started the reign of dinosaurs. More than 200 million years separate us from this catastrophe (also called the End-Triassic Extinction), but it could contain some lessons for us today, says Olsen. For one, it may have been [...]
One hour from New York City, where the suburbs of New Jersey give way to farms, a team of scientists are drilling for ancient rocks on the edge of a cornfield. The rocks hold clues about what the earth was like about 201 million years ago,during the great extinction that allowed dinosaurs to dominate. Listen [...]