[Lee Stewart]

The biggest mammals that escaped the global die-off weighed no more than a pound. But just 100,000 years later, the largest species among their descendants were about 13 pounds, as heavy as a modern raccoon. And another 200,000 years later, “the largest mammals had again tripled in weight, to about 45 pounds,” Lyson says. That’s about as heavy as an American beaver, and much heavier than any pre-extinction mammals.