Scientists have discovered a new human species that went extinct 200,000 years ago in China.

They found the remains of 16 individuals, which featured large heads, wide skulls and immense teeth.

Their head measurements, which were bigger than Neanderthals and Homo sapiens, led the team to naming a new prehistoric species called Homo juluensis.

The fossilized remains were found alongside thousands of artifacts, stone tools and animal bones that revealed more about their lives, such as they were hunters who fashioned clothing from animal hides.

Researchers believe the species lived in small groups that likely disappeared when modern humans started to migrate to Europe and Asia 120,000 years ago. 

Homo juluensis lived during a dramatic climate shift that saw a glacial period, which caused cooler and dryer weather to sweep in. 

Because Homo juluensis lived in small groups, it made them vulnerable to becoming trapped in furious weather event that may have led to their demise.

'This is part of the reason why the population density of Homo juluensis is probably never as big as when modern humans moved out of Africa … in larger numbers,' Bae told the Post. 

'They genetically swamped the indigenous populations like neanderthalensis and juluensis.'

'The eastern Asian record is prompting us to recognize just how complex human evolution is more generally and really forcing us to revise and rethink our interpretations of various evolutionary models to better match the growing fossil record,' the study's co-author Christopher Bae told the South China Morning Post.

Researchers at the University of Honolulu and the Chinese Academy of Sciences reported that the Homo juluensis skulls measured between 103 and 109 cubic inches.

This was compared to Neanderthals' craniums that were 88 cubic inches and Homo sapiens which measure 82 cubic inches. 

However, Bae cautioned that the size disparity does not necessarily mean the ancient species had a higher intelligence than modern-day humans.

The researchers compared the fossils to those of Neanderthals and Denisovans -  whose bone fragments were discovered in a southern Siberian cave in 2008.  

Their findings led researchers to believe they weren't connected to Neanderthals, who existed in Europe and Asia until about 40,000 years ago.

However, they noted that the Homo juluensis species shared similarities to Denisovans because of their matching teeth traits.

'One of the things that always stood out about the Denisova molars was that they were quite large. The molars from Xujiayao from our type specimen are also quite large,' Bae said.

They looked at a comparison of the biting surfaces, where the bottom and top teeth came into contact while chewing and and that the surface of the molars were 'almost exactly the same.' 

Using dating analysis, the researchers argued that Denisova is not its own species, but is rather the name of a general population of ancient people, adding that it 'likely belongs to Homo juluensis based on their similarities.'

Bae reported that the stone tools, artifacts and animal bones indicated that Homo juluensis lived off wild horses and processed them at the Xujiayao site where their fossils were found.

They hunted the horses as a group and used their entire bodies to sustain themselves including consuming the meat, marrow and cartilage and using the hides to make clothing to protect them from the brutal winters. 

The study, published in the journal Nature, said the new species likely formed due to a combination of crossing their genetics with homo sapiens and migrating to new locations throughout the Late Quaternary period - which began 300,000 years ago.

'Recent research initiatives in China, and broader eastern Asia, are showing clearly that multiple hominin lineages were present during the Late Quaternary,' the study said.

This time period was categorized by major shifts in climate change that caused recurring glacial periods that drove the extinction of ancient human species.

The study's authors stated that the 'diversity among ... human fossils from eastern Asia is greater than we expected.'

They added that their findings have given researchers 'a greater appreciation for the degree of complexity that is present' in the region.