Unique line of tigers found in fossils

China University of Geosciences in Wuhan, Hubei province, announced that researchers had recently discovered fossils of an extinct tiger branch species with a history of more than 43,500 years.

The researchers named the species "Da'an tiger" after the location where they discovered the special fossils, the university said in a statement.

"This was a rare research achievement — the first time in the world the genome of ancient tigers has been discovered," it said.

News of the discovery, made by the university's ancient DNA team headed by professor Lai Xulong and counterparts from China's Jilin University and Denmark's University of Copenhagen, was recently published in the well-known journal Proceedings of the Royal Society B (PRSB): Biological Sciences.

Biologically, tigers belong to the cat family, leopard genus and tiger species. Their evolutionary history and survival status have attracted extensive attention in social and academic circles.

Today's tigers include six geographical subspecies, including the Siberian tiger, South China tiger, Indo-Chinese tiger, Bengal tiger, Malay tiger and Sumatran tiger. They all descend from the same ancestral population, whose history spans about 110,000 years.

The Da'an tiger found this time is a new branch that did not belong to the same ancestral population of today's tigers.

"Even if going back about 260,000 years, the ancestral population of the Da'an tiger had separated from the ancestors of existing tigers," the statement said.

The existing tiger population is orthodox, while the Da'an population is a collateral branch. It became extinct when it did not adapt to the environment after separation, scientists said.