THE amazing discovery of an “alien” skull has sparked claims of an ancient civilisation.

The bizarre “alien” skull was discovered in China and is brownish and roughly 16 centimeters in diameter.

Li Jianmin, a science fiction author and researcher, revealed his find at a small seminar held in Beijing last month.

He claims it is not human, but rather has two “distinct layers.”

The 55-year-old said the unique skull belongs to a private collector who had acquired it from a street vendor in Inner Mongolia Autonomous Region.

“The collector was flipping through my novel when he discovered that the skull looked very much like the one in an illustration,” Li explained.

“He asked me to confirm its origins.”

The collector got in touch with Jianmin, who set about producing a 103-page study over the subsequent four months to support claims that the skull is real.

The author said that he carried out a Raman spectroscopy and used an atomic force microscope to compare the cranium with other alleged alien skulls found in other countries.

However, Li said he needs funds to continue with further tests.

Despite being widely mocked on social networks, Jianmin is convinced the skull is real, adding: “I welcome questions and scepticism, but if you decide to challenge me, be sure to bring along evidence.”

Some were not convinced of the discovery.

But others hailed it as proof of an ancient alien civilisation.

One replied on Twitter: “This is not real.”

Another said: “That is not a skull.”

But a third argued: “OMG this is amazing. This is proof we were not the first ones here.”

This isn’t the first “alien” discovery to baffle experts.

A skeleton which has a dramatically elongated skull and an underdeveloped jaw and face was found in Chilie’s Atacama Desert in 2003.

The bizarre find sent conspiracy theorists wild – with people suggesting the bones were those of an aborted fetus, a monkey, or even an alien that had crash-landed on earth.

But researchers concluded the skeleton belonged to a human.

And another bizarre  “cone-shaped skull” was discovered earlier this year.