Thanks to some Neanderthal skulls in a Spanish cave, researchers believe the earliest humans evolved in different stages and began with the face and teeth.

According to NBC News, the new study, published in the journal Science, is based on 17 reconstructed skulls found in the Sima de los Huesos cave in Spain. The researchers also found that clans competed against one another the way the different houses do in the popular fantasy series "Game of Thrones."

"It is now clear that the full suite of Neanderthal characteristics didn't evolve at the same pace," study lead author Juan-Luis Arsuaga, a paleontologist at the Complutense University of Madrid, told NBC News.

The researchers also noted that glaciers were drifting south from Eurasia's northern reaches, which would have contributed to evolution. 400,000 years ago, family ties also knit these communities tightly.

"Winter is coming," Arsuaga said to mimic the saying associated with the Starks, one of the major "Game of Thrones" houses.

In George R.R. Martin's series of fantasy epics, adapted into an HBO television show, various houses vie for power over the realm. Various houses have different strengths, weaknesses, personas and values; some also are older than others and have more land, money and armies.

Arsuaga said this system of different clans and a lack of one truly omnipotent kingdom was very similar to Martin's world.

"As in the famous saga, there was never a unified and uniform middle Pleistocene kingdom, but a number of houses living in different regions and often competing for the land," Arsuaga told the Los Angeles Times.

For their study, the researchers used six distinct techniques to date the fossils, previously believed to be as old as 600,000 years. More accurate estimations of the skulls' age helped the researchers learn how the Neanderthals and early humans diverged in their evolution.

"As a result of this study we are able to answer two of the most important questions that surround the Sima de los Huesos fossil assemblage: Who were these people? And when were they living on the landscape?" study co-author Lee Arnold, a geochronologist at the University of Adelaide in Australia, told Reuters. "Both these findings are critical to better understanding the complex patterns of human evolution across Europe during the Middle Pleistocene, not least because the site contains more than 80 percent of the world's known Middle Pleistocene fossil record for the genus Homo."