Fossil find tells story of rise of the mammals
It begins with asteroid that killed off dinosaurs
Sixty-six million years ago, the asteroid that wiped out the dinosaurs also ushered in the age of the mammals – an age that continues to this day.
Scientists have known little about the mammals that survived and flourished in the years after the asteroid impact. Until now. A study on a recent discovery of thousands of mammal fossils at a nature preserve near Colorado Springs, Colorado, has shed light on the little-understood era.
“Our understanding of the asteroid’s aftermath has been spotty,” said study lead author Tyler Lyson of the Denver Museum of Nature and Science. “These fossils tell us for the first time how exactly our planet recovered from this global cataclysm.”
When the asteroid slammed into what’s now the Yucatan Peninsula in southeastern Mexico, it wiped out 75% of all living species, including any mammal much larger than a rat. Half the plant species died out. With the dinosaurs gone, mammals thrived.
The study traces that process “in exquisite detail” as land mammals began to expand from small creatures into the wide array of forms we see today – including us, said the journal Science, where the study was published.
“Were it not for the asteroid, humans would never have evolved,” Ian Miller of the Denver Museum of Nature and Science told Reuters. “One message I would like people to take from this is that their earliest ancestors – and by ancestors we’re talking fuzzy little squirrel-like critters – had their origins in the wake of the extinction of the dinosaurs.”