The most promising fossil yet found that could be evidence of Denisovans came from a cave in Tibet: a massive jaw with two stout molars, dating back at least 160,000 years. In 2019, scientists isolated proteins from the jaw, and their molecular makeup suggests they belonged to a Denisovan, rather than a modern human or Neanderthal.
This molecular evidence — combined with fossil evidence — suggests that the common ancestors of Homo sapiens, Neanderthals and Denisovans lived 600,000 years ago.
Our lineage split off on its own, and then 400,000 years ago, Neanderthals and Denisovans diverged. In other words, Neanderthals and Denisovans were our closest extinct relatives. They even interbred with the ancestors of modern humans, and we carry bits of their DNA today.
But many puzzles still endure from this stage of human history — especially in East Asia. Over the past few decades, paleoanthropologists have found a number of fossils, many incomplete or damaged, that have some features that make them look like our own species and other features that suggest they belong elsewhere on the hominin family tree.
Katerina Harvati, a paleoanthropologist at the University of Tübingen in Germany who was not involved in the new study, said that the Dragon Man skull could “help clarify some of the confusion.”
To figure out how Homo longi fits into the human family tree, the scientists compared its anatomy with 54 hominin fossils. The researchers found that it belongs to a lineage that includes the jaw in Tibet that has been identified as a Denisovan.
The skull was even more similar to a portion of a skull discovered in 1978 in the Chinese county of Dali, dating back 200,000 years. Some researchers thought the Dali fossil was of our own species, while others thought it belonged to an older lineage. Still others even called the fossil a new species, Homo daliensis.