Part donkey, part wild ass, the kunga is the oldest known hybrid bred by humans

The mysterious equines were bred in Syria 4,500 years ago, likely for use in warfare

fossilized skeletons of four kungas lying side by side

Genetic analysis pegged these ancient and mysterious equine skeletons as donkey-wild ass hybrids. They were excavated from the 4,500-year-old burial complex at Umm el-Marra in northern Syria.

© Glenn Schwartz/Johns Hopkins University

From mules to ligers, the list of human-made hybrid animals is long.