after 66 million years agoReputable sourceWell documented
After the Dinosaurs: The Age of Mammals
On the timeline · around after 66 million years ago · After the Dinosaurs
What happened
With the non-bird dinosaurs gone, mammals — until then mostly small and nocturnal — rapidly diversified to fill the empty ecosystems, growing larger and taking on new roles through the Cenozoic Era.
Why it matters
The extinction that ended the dinosaurs opened the way for the age of mammals — and, ultimately, for primates and human beings.
Sources
- University of California Museum of Paleontology. The Cenozoic Era · Reputable source
Related timelines
- Evolution of Life on Earth → — The Cenozoic — the age of mammals and, eventually, us