The last known Pyrenean ibex, a female named Celia, was killed by a falling tree in the Ordesa y Monte Perdido National Park in January 2000. Tissue had been taken from her the previous year and cryopreserved, a decision made specifically against the possibility of extinction.
In 2003 a Spanish and French team transferred nuclei from those cells into enucleated domestic goat eggs and implanted the embryos into goat and goat-ibex hybrid surrogates. One pregnancy reached term. The kid was born alive but had a malformed extra lobe on one lung and died after roughly seven to ten minutes. It remains the only cloned animal born from an extinct taxon.
The episode is often cited as a de-extinction proof of concept, which overstates it. Only one female's genome was available, so even a surviving clone would have been a single individual with no genetic diversity behind it and no path to a population. The exercise demonstrated that the cloning step is possible, not that a lost population can be restored.