The Only Animal That Went Extinct Twice

According to scientists, the Earth is experiencing its sixth great extinction event, as The Guardian reports. The truth of the matter is, plant and animal species have gone extinct for as long as there has been life on Earth: Sometimes for natural reasons, other times for reasons related to humans, as is currently the case. In a twist on that narrative, though, there's one species that's known to have come back from oblivion, only to disappear again a short time later, making it the only animal in history that's gone extinct twice.

According to Britannica, the Pyrenean ibex lived in the Pyrenees mountain range of Portugal and the Basque regions of Northern Spain. That was their territory from the end of the last Ice Age (via Forbes). Since they were heavily hunted for their curled horns, conservation efforts throughout the 1980s were largely unsuccessful, and by the late 1990s, there was thought to be only one "bucardo" left in the wild — as the ibex is commonly called. This did not bode well for the future of the species, and by the year 2000 that sole survivor, named "Celia," was dead, crushed under a fallen tree. With that, the Pyrenean ibex disappeared from the Earth after some 18,000 years.

The Pyrenean ibex was gone — that is, until about one year later, when scientists attempted to revive the species, as IFL Science reports. Scientists had captured the female ibex that was later found dead. Cellular samples were taken from several points on the animal's body and preserved in deep freeze. No one knew if cloning an animal — extinct or not — could produce viable offspring. Aware of recent success cloning sheep, scientists tried to clone that bucardo, and by doing so, return an animal from extinction for the first time in history, a process called "de-extinction," according to Forbes. In the process, 500 cloned ibex embryos were implanted in about 150 goats, and scientists waited.

It seemed at first that the experiment was a success. Five of the sheep became impregnated, and one delivered a living, breathing, Pyrenean ibex. With encouraging vital signs, the Pyrenean ibex, it seemed, was saved from extinction and could roam the Earth once more, just as scientists hoped. Their joy was not long lasting. Only a matter of seconds after the incredible animal was born, it died, unable to breathe with an extra lobe in her lung. This was not an unexpected outcome. As Jose Folch, a scientist involved in the experiment later wrote, "Physical defects in the lungs as well as in other organs have also been reported in neonatal cloned sheep that failed to survive" (via Forbes).