The study is a direct contradiction of the theory that the extinction of dinosaurs about 65 million years ago triggered the rapid rise of mammals on the planet.
The study says that it was only 10 million to 15 million years after the dinosaurs were extinct that mammals began flourishing on the planet. Some mammals like primates, rodents and hoofed animals did survive the extinction of the dinosaurs, the scientists led by Olaf R. P. Bininda-Emonds of the Technical University of Munich said.
The researchers used 4,500 species of mammals as well as fossils of some of the extinct mammals to trace the origin of the mammalian period on Earth. The dinosaurs flourished 225 million years ago and eventually became extinct some 65 million years ago.
The scientists found that the first mammal appeared around 200 million years ago, but the first direct relative of today's mammals was seen 125 million years ago.
"The common perception is that the mammals rose to their current status after the dinosaurs went extinct. While it is true that there is an increase in mammal diversity after this time, and the fossil record shows this quite clearly, it is not in the mammals we see around us today," Bininda-Emonds said, adding that the mammals, which could have benefited from the death of the dinosaurs are now extinct.