When a type of animal or plant is extinct, it means that every single one of them has died and none exist anywhere on Earth anymore. When we say dinosaurs are extinct, we mean there are no living dinosaurs left to find, not in jungles or oceans or anywhere else. They're gone forever.

Scientists know about many extinct animals from fossils, which are preserved remains in rock. The dodo bird went extinct in the 1600s when humans hunted them all and destroyed their habitat on an island in the Indian Ocean. The woolly mammoth went extinct around 4,000 years ago. Unlike animals that are endangered (meaning very few are left), extinct species can never come back naturally.

Sometimes people use the word more loosely to describe things that have completely disappeared. You might hear someone say that eight-track tapes are practically extinct, or that a particular style of music has gone extinct. They mean these things have vanished so completely that you'd be hard-pressed to find them anymore.

When a species becomes extinct, that particular flame of life has gone out forever. That's why conservation efforts try to protect endangered animals before they reach the point where extinction becomes inevitable.