Mammals were already poised to take over the world before the dino-killing asteroid struck

66 million years ago, an asteroid slammed into Earth, killing off dinosaurs. In the shadows, tiny mammals were able to survive and thrive in the aftermath of the disaster.

The study, which was published in the journal Science Advances, mapped the complex interactions between ancient animals and their environment before and after the asteroid hit. Between the end of the Cretaceous period and the beginning of the Paleogene, the ages of fossils gathered in western North America are 146 million to 66 million years old. There are more than 500 genera of animals, including mammals, fish, crocodilians, birds and nonavian dinosaurs.

The authors were able to determine that mammals and freshwater organisms were more resistant to extinction than non-avian dinosaurs. According to Live Science, they made a compelling case that mammals diversified before the asteroid strike.

The evolution resulted in mammals that could eat a wide variety of foods, live in a range of temperatures and weather conditions, and produce offspring quickly so as to bounce back from population crashes.

When the asteroid slammed into Earth, what happened?

The Senckenberg Biodiversity and Climate Research Centre (S BiK-F) in Germany has a researcher who says that scientists used to think that mammal evolution exploded because of the dinosaur die-off. She told Live Science that the new study shows that mammals were already expanding into new niches before the impact.

The environment of the U.S. back then would have been similar to Florida's swamp. The climate was cooling towards the end of the Cretaceous period.

The study found that the dinosaurs didn't adapt. They kept the same temperature ranges, weather conditions and diet. Their ecological roles were largely stable, except for the fact that the diversity of big, plant-eating dinosaurs decreased and their influence in the food web decreased.

mammals jumped from oneclimatic niche to another and adopted a broader habitat range and diet during the same period When the asteroid plunged the Earth into sudden cold and darkness, mammals had the flexibility to adapt. "That eventually turns out to be a great trait, when something changed so dramatically because of the asteroid impact."

The approach used in the study was originally developed to study modern ecosystems according to the co-first author. The models are difficult to apply to ancient animals because of the incomplete fossil record, but the team made an effort to account for these factors.

The study focuses on fossils from the U.S. The global picture of what happened around the end-Cretaceous extinction could eventually be given by models based on additional locations.

The current model helps explain why our mammal ancestors were able to survive the impact winter.

It did not take long for our ancestors to move into vacant niches after the asteroid hit. He said that the modeling shows how life finds a way.