Geologists are the ones that deal with the history of the Earth's changes the most. They have broken that history down into many different names (14). The current era is the Cenozoic and it started 65 million years ago. Geologists picked that point because that was when the Chicxulub asteroid hit the Earth and wiped out ~75% of all species on the Earth (15). That is one of those traumatic events that occasionally happen to the Earth. Just like a car crash can change a person’s life, the beginning of this era started with a large and sudden change to the Earth.
