From feathers to fur

It also remains a mystery how mammals appeared almost suddenly millions of years after the dinosaurs, creatures more closely linked to our modern birds, became extinct. The connections between these two different orders of animals are so far apart that linking them is close to impossible.

7. When did “giant animals” become extinct?

Giant animals, scientifically referred to as megafauna, roamed the face of the Earth for millions of years until they completely died out 10,000 years ago. Animals like the magnificent woolly mammoth belonged to this group and no one knows what really caused their extinction.