Which endangered animal is the source of the world's finest, lightest, warmest and most expensive wool - the shahtoosh?

Explanation

The source of the world's finest, lightest, warmest, and most expensive wool known as "shahtoosh" is the Tibetan antelope, also known as the chiru (Pantholops hodgsonii). Shahtoosh is made from the downy undercoat of the Tibetan antelope, which is native to the Tibetan Plateau and surrounding regions in Central Asia. The production of shahtoosh wool is illegal and highly unethical due to the endangered status of the Tibetan antelope. The chiru is protected by international and national laws, and trade in shahtoosh products is banned to prevent the poaching and endangerment of these animals. The demand for shahtoosh has contributed to the decline of chiru populations, and conservation efforts are in place to protect this endangered species.