“Our study suggests that it was probably the interplay between their body size, diet, behavior and a number of other ecological characteristics, including ecological plasticity, that prepared some smaller animals for greater survival after the asteroid impact ,” said Alfio Alessandro, a paleontologist and co-author of the study. Chierenza of the University of Vigo in Spain.
Pre-asteroid mammals included a now-extinct rodent-like group called multituberculates, as well as relatives of today’s marsupials called metatherians and relatives of today’s placentals called eutherians.
After the mass extinction, new mammals emerged, including many true placentals – the group that gives birth to well-developed young, comprising most of today’s mammals from whales to bats and aardvarks to humans Are included. Post-apocalyptic mammals expanded rapidly in body size and ecological diversity.
“Mammals and dinosaurs have the same origin story — they both originated and began to diversify back in the Triassic period on the supercontinent of Pangaea, about 230 million years ago,” Brusatte said.
“From there, they went their separate ways, dinosaurs going for grandeur and smaller-sized mammals relegated to the shadows,” Brusatte said. “But their fates will forever be intertwined. Mammals were there when the asteroid hit. They made it. Our ancestors were the ones who stared down the asteroid.”