Answer:
Dinosaurs went extinct about 65 million years ago (at
the end of the Cretaceous Period), after living on
Earth for about 165 million years. If all of Earth
time from the very beginning of the dinosaurs to today
were compressed into 365 days (1 calendar year), the
dinosaurs appeared January 1 and became extinct the
third week of September. (Using this same time scale,
the Earth would have formed approximately 18.5 years
earlier.) By comparison, people (Homo sapiens) have
been on earth only since December 31 (New Year's eve).
The dinosaurs' long period of dominance certainly
makes them unqualified successes in the history of
life on Earth.
