6 things to know about Earth's 6th mass extinction

School-age boy saves a species after quest to find an 'extinct' frog

The sun may have an evil twin with a flare for mass extinction

8 species on life support

Tasmanian tiger 'sightings' prompt new scientific hunt

Earth's tiniest porpoise approaches extinction

Should we resurrect extinct species?

14 extinct animals that could be resurrected

9 extinct megafauna that are out of this world

Hawaiian crows return from extinction in wild

Baby dinosaur's tail — with feathers — found in 99 million-year-old amber

7 interesting facts about Lucy the ancient ape