New York – An impressive cluster of fossils from Colorado has revealed details about how mammals reached larger sizes and how plants evolved after the cataclysm that exterminated dinosaurs.
Thousands of specimens allow scientists to trace that story over a period of one million years, a simple flicker in the life of the Earth.
66 million years ago, a huge meteorite crashed into what is now the Yucatan Peninsula, in southeastern Mexico. Its fall unleashed hot waves of heat and covered the sky with particles that blocked the sunlight for months, which ended with plants and animals that depended on them.RELATED
More than three quarters of the terrestrial species disappeared.
But life returned, and land mammals went from being small creatures to the wide variety of forms we see today, including us.
So the new finding offers an overview of "the origin of the modern world," said Tyler Lyson, one of the authors of the article on the study of fossils and was published Thursday in the journal Science.
The fossils were recovered from an area of steep cliffs that cover about 10 square miles near Colorado Springs, starting three years ago.
Lyson, of the Denver Museum of Nature and Science, found little in that area when he followed the standard practice of looking for bone fragments by scanning. But that changed once he started looking for rocks that can form around a bone. When the rocks were broken, they began to reveal skulls and other fossils inside.
Lyson said it is unclear how extensive the geographical region to which fossil recovery history can be applied, but that he believes they show what happened in North America.
"We know very little about this," he said. "At least now we have a place with a fantastic record."
Experts unrelated to the study said they were excited about the finding.
This is "an incomparable documentary about how life on earth recovered" after the impact of the asteroid, said P. David Polly, of the University of Indiana at Bloomington. "The huge amount of fossil specimens and the quality of their preservation are exceptional."
The history of fossils certainly represents what happened in central North America and perhaps more extensively, he wrote in an email.
Stephanie Smith, from the Field Museum in Chicago, said the detailed focus of the study in one area area allows scientists to understand the complexity of recovery when combined with the results of studies conducted elsewhere.