It was a dire moment for life on Earth. Runaway global warming triggered by calamitous volcanism in Siberia inflicted the worst mass extinction on record - dooming perhaps 90% of species - roughly 252 million years ago at the end of the Permian Period.
Unlike the asteroid 66 million years ago that ravaged the dinosaurs, this extinction event unfolded over a protracted time span, with species perishing one by one as conditions worsened. Scientists said on Monday fossils unearthed in South Africa provide a peek into this drama, telling the tale of an apex predator that over multiple generations migrated halfway around the world in a desperate, and ultimately failed, bid to survive.
This beast, a tiger-sized, saber-toothed mammal forerunner called Inostrancevia, had been known only from fossils excavated in Russia's northwestern corner bordering the Arctic Sea until new remains were discovered at a farm in central South Africa.
