There are several factors that can lead to mass extinction identify at least 3 of these causes and explain how they lead to a mass extinction

1) Hunting: People can over-hunt a species killing too many of them too fast.
2) Global warming: A place can get to hot for them to survive their anymore like coral reefs for example.
3) Destruction of habitats: This can leave animals defenseless and open to attack.    

Ba rock that formed 1,400 million years ago!