BSL Biology Glossary - extinct - definition
Definition: Animals and plants may be existing quite happily but then the environment around them changes. Some species are fine but maybe one specific species can't cope. That one species dies out completely so there are none of that species left. For example, humans who shoot one species of animal may cause it to become extinct. Another example is, in prehistory, dinosaurs roamed the earth until a meteorite hit the earth and eradicated them, made them extinct.