New research reveals mammals were abandoning trees millions of years before the asteroid hit changing everything we know ...

During the early Paleocene, about 66 to 56 million years ago, a species of small mammal known as Mixodectes pungens […] ...

They wouldn't have encountered a speck of ice; even before the events we're talking about, Earth was already much warmer than it is today. But as the Paleocene epoch gave way to the Eocene ...

The event is known as the Palaeocene-Eocene Thermal Maximum (PETM ... porpoises and dolphins would not exist if it weren’t for Earth resembling some form of enormous sauna.