Who killed extinct animals?
Extinction of a particular species of animals is not done by any fixed source. Extinction of a particular species of an animal has many reasons which are explained down below.
"Extinction", refers to a state where a particular species of animal doesn't exists any more. There are many causes of extinction of a particular species like change in the climate of a region due to global warming, reduced food supply of a particular region,hunting, human interactions, pollution, loss of habitat and many others. In general, we cannot say that a particular factor is responsible for extinction of all species. Every animal specie have there distinct causes for extinction. For e.g., Dodo bird does not exists any more now. The main considered reason behind its extinction was its hunting by the travellers. You will find some more species in nature who no longer exist on earth due to the same reason but not all species extinct due to hunting.