A remarkable trove of fossils from Colorado has revealed details of how mammals grew larger and plants evolved after the cataclysm that killed the dinosaurs.
The thousands of specimens let scientists trace that history over a span of 1 million years, a mere eyeblink in Earth's lifespan.
It's "an unparalleled documentary of how life on land recovered" after the asteroid impact, said P. David Polly of Indiana University in Bloomington. "The sheer number of fossil specimens and the quality of their preservation are exceptional" for this time period, he said.
The fossils' story certainly represents what happened in central North America and perhaps more broadly, he wrote in an email.