For all our Dino Defenders out there, when researching those prehistoric beasts the topic of "extinction" will always come up. But what exactly does it mean for a species to be extinct? And are Dinosaurs the only creatures on our planet to go extinct? Well to put it simply, the moment of extinction for a species is when the last individual of that species has died. That means none are left, they cannot reproduce, and the species can now only be studied and understood through their remains. Sometimes, a species can become "functionally extinct" before the last individual dies, which is usually when the population isn't big enough to make an impact on their ecosystem, and the remaining living individuals won't be able to reproduce much longer, if at all, so soon they will be completely extinct. Even though Dinosaurs are often the most famous, the truth is that 99% of ALL species to ever exist, have gone extinct. If you think our planet has diverse life right now, imagine if we had EVERY species that ever existed living here at once!