The researchers analyzed fossils and genetic data to determine when the first placental mammals appeared and how they evolved during the period when dinosaurs dominated Earth.
As a result, it was found that the first placental mammals appeared about 200 million years ago, but their diversity and distribution increased significantly only a few million years before the asteroid impact.
This discovery implies that placental mammals were only able to coexist with dinosaurs for a short period of time. This is likely due to changes in the ecosystem and the availability of resources after the catastrophic asteroid impact.
This new data raises interesting questions about the interactions between placental mammals and dinosaurs.
It was previously believed that dinosaurs were the only dominant life forms on Earth at that time, but it is now clear that placental mammals also played an important role in the ecosystem.
This discovery is also important for our understanding of the evolution and survival of organisms.
Placental mammals, including humans, are one of the most successful and diverse groups of organisms on Earth, and their coexistence with dinosaurs may be one reason for their remarkable success.
