The discovery of skull fragments in Tibet belonging to a previously unidentified big cat supports the theory that the felines evolved and spread from central Asia, not Africa, BBC News reported.

Scientists estimated the skull of the newly named Panthera blytheae was between 4.1 million and 5.95 million years old. The team of American and Chinese paleontologists reported their findings in the Royal Society Journal Proceedings B.

The scientists used anatomical and DNA data to determine the skull was of a big cat and said it most resembled a snow leopard. The newly discovered species likely overlapped in its existence with many big cat species alive today.

"This cat is a sister of living snow leopards - it has a broad forehead and a short face. But it's a little smaller - the size of clouded leopards," said lead author Dr. Jack Tseng, of the University of Southern California. "This ties up a lot of questions we had on how these animals evolved and spread throughout the world."

"Big cats" are the common name for the subfamily known as Pantherinae, which include lions, tigers, leopards, snow leopards and clouded leopards. Also related is the Felinae subfamily, which include cougars, lynxes and domestic cats.

The new fossils were discovered in 2010 by a team including Tseng and his wife, also a fellow paleontologist, Juan Liu. Among the discovery of about 100 bones was the crushed, but mostly intact, skull.

"We were very surprised to find a cat fossil in that basin," Dr. Tseng said. "Usually we find antelopes and rhinos, but this site was special. We found multiple carnivores - badgers, weasels and foxes."

The nearly complete skull was about 4.4 million years old, but the rest of the bones ranged from 4.1 million to 5.95 million years old.

"This is a very significant finding - it fills a very wide gap in the fossil record," said Dr. Manabu Sakamoto of the University of Bristol, an expert on Pantherinae evolution not involved in the study. "The discovery presents strong support for the Asian origin hypothesis for the big cats."

Tseng and his team plan to return to the site to try and find more specimens. William Murphy, a Texas A&M University professor not involved in the study, was skeptical of the researchers' findings. He questioned if the big cat really was related to the snow leopard.

"The authors' claim that this skull is similar to the snow leopard is very weakly supported based on morphological characters alone, and this morphology-based tree is inconsistent with the DNA-based tree of living cats," the big cat expert told BBC News. "It remains equally probable that this fossil is ancestral to the living big cats. More complete skeletons would be beneficial to confirm their findings."