In the course of the Earth's long history, countless animals have roamed the land, sea, and skies. Some went extinct due to climate change or geologic upheavals; others perished during the asteroid collision that ended the Mesozoic era 65 million years ago.
In the last few centuries, humans have been the leading cause of several extinctions due to overhunting, the introduction of invasive species, and the erosion of natural habitats. Some lost species, like the dodo bird, were wiped out before the age of photography. Others, like the Barbary lion and Bali tiger, were photographed around the turn of the 20th century, when the last living remnants existed in captivity.
The following photos of extinct animals include the final glimpses of vanished species. They exist now only as bones in museums and pictures in history books.