Woolly mammoths are prime candidates for de-extinction. Many specimens are preserved in Siberian permafrost, and scientists have sequenced their genome.

Cloning extinct animals is possible! The Pyrenean ibex became the first to be "un-extinct" for seven minutes before dying again.

Saber-toothed cats had epic canine teeth. Fossil specimens survive thanks to frigid habitats and tar deposits, but usable ancient DNA is uncertain.

Moa birds, once the largest birds on Earth, went extinct 600 years ago. Their feathers and eggs remain intact, and scientists have extracted their DNA.

The dodo, extinct 80 years after discovery, had no natural predators in Mauritius. Its defenseless nature made it vulnerable to human impact.

Ground sloths, related to modern three-toed sloths, lived until 8,000 years ago. DNA from their intact hair remains offers de-extinction potential.

The Carolina parakeet, the only native parrot of the U.S., went extinct in 1918. DNA from mounted birds and feathers may enable its cloning.

The woolly rhinoceros roamed the Arctic tundra 10,000 years ago. It is depicted in ancient cave art and its remains could help in de-extinction efforts.