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Paleobotanists exploring a site near the Dead Sea have unearthed a startling connection between today's conifer forests in the Southern Hemisphere and an unimaginably distant time torn apart by a global cataclysm. Exquisitely preserved plant fossils show the podocarps, a group of ancient evergreens that includes the massive yellowwood of South Africa and the red pine of New Zealand, thrived in the Permian period, more than 250 million years ago. That's tens of millions of years earlier than thought, and it shows that early podocarps survived the "great dying" at the end of the Permian, the worst mass extinction the...

Ancient mega-catastrophe paved way for the dinosaurs, spawned Australian continent. Planetary scientists have found evidence of a meteor impact much larger and earlier than the one that killed the dinosaurs -- an impact that they believe caused the biggest mass extinction in Earth's history.The 300-mile-wide crater lies hidden more than a mile beneath the East Antarctic Ice Sheet. And the gravity measurements that reveal its existence suggest that it could date back about 250 million years -- the time of the Permian-Triassic extinction, when almost all animal life on Earth died out.Its size and location -- in the Wilkes Land...

Did a Planetary Society citizen scientist help find one of Earth’s biggest impact craters? About 66 million years ago, a 10-kilometer-wide hunk of rock smashed into Earth near what is now Mexico's Yucatán Peninsula.The impact created a global dust cloud that snuffed out the sunlight, leading to the demise of 80 percent of Earth's plants and animals—including most of the dinosaurs. A 200-kilometer-wide crater buried near the city of Chicxulub is all that's left. It's ground zero for one of the world's most notable extinction events.But throughout Earth's history, there have actually been five major extinction events. The largest of...