Originally Posted by Oppai

When life began in prehistoric times, earth belonged to what we known as "Dinosaurs, Bugs, Animals". Until one day, a group of aliens(us) flew down in a spacecraft which crash landed and created a massive explosion and wiped out 3/4 of earths animals. The aliens(us) wanted to know more about this so called "earth", therefore, they flew down another spacecraft filled with 50 people.