Episode 438: The Dragon Man Skull

This week we’re going to learn about a new finding about the skull referred to as the Dragon Man! Further reading: We’ve had a Denisovan skull since the 1930s—only nobody knew The proteome of the late Middle Pleistocene Harbin individual Show transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. It never fails that only a few days after our annual updates episode, a study is published that’s an important update to an older episode. This time it’s an update so important that it deserves its own episode, so let’s learn more about one of our own extinct close relations, the Denisovan people. We didn’t know about the Denisovans until 2010, when DNA was sequenced from a finger bone found in Denisova Cave in Siberia in 2008. Scientists were surprised when the DNA didn’t match up with Neanderthal DNA, which is what they expected, since they knew Neanderthals had lived in the cave at various times over thousands of years. Instead, the DNA was for a completely different hominin, a close relation of both humans and Neanderthals. Since then, researchers have found some Denisovan teeth, two partial mandibles, a rib fragment, and some other bone fragments, but nothing that could act as a type specimen. The type specimen is the preserved specimen of a new species, which is kept for scientists to study. It needs to be as complete as possible, so a handful of fragments just won’t work. Even without a type specimen, having Denisovan DNA answered some questions about our own history as a species. Ever since scientists have been able to sequence genetic material from ancient bones, they’ve noticed something weird going on with our DNA. Some populations of people show small traces of DNA not found in other human populations, so scientists suspected they were from long-ago cross-breeding with other hominin species. When the Neanderthal genome was sequenced, it matched some of the unknown DNA traces, but not all of them. Mystery DNA sequences in a closely related population are called ghost lineages. The Denisovan DNA matched the ghost lineage scientists had identified in some populations of people, especially ones in parts of east Asia, Australia, and New Guinea. This is your reminder that despite tiny genetic differences like these, all humans alive today are 100% human. We are all Homo sapiens. Naturally, we as humans are interested in our family tree. We even have an entire field of study dedicated to studying ancient humans and hominins, paleoanthropology. Lots of scientists have studied the Denisovan remains we’ve found, along with the genetic material, but they really need a skull to learn so much more about our long-extinct distant relations. Luckily, we’ve had a Denisovan skull since the 1930s. But wait, you may be saying, you just said we didn’t have anything but bone fragments and teeth! Why didn’t you mention the skull? It’s because the skull was hidden by its finder, a Chinese construction worker. The man was helping build a bridge and was ashamed that he was working for a Japanese company. That region of China was under Japanese occupation at the time, and the man didn’t want anyone to know that he was working for people who were treating his fellow citizens badly. He thought the skull was an important find similar to the Peking Man discovery in 1929, so he hid the skull at the bottom of an abandoned well to keep it safe. He didn’t dare share any information about it until he was on his death-bed, when he whispered his secret to his son. It wasn’t until 2018 that the man’s family took another look at the skull and realized it definitely wasn’t an ordinary human skull. It was obviously extremely old and had a pronounced brow and really big teeth. In 2021 the skull was classified as a new species of hominin, Homo longi, where the second word comes from the Mandarin word for dragon. That’s because the area where it was found is called Dragon River. But not everyone agreed that the Dragon Man skull, as it came to be known, was actually a new species. Scientists continued to study the skull, and finally, a paleoanthropologist named Qiaomei Fu and her team managed to extract DNA from the skull and one of its teeth. The resulting genetic profile indicated that the Dragon Man was a Denisovan. The skull has been dated to 146,000 years ago, possibly older. It’s nearly complete, which provides a lot of information to scientists. Scientists are pretty sure Dragon Man was a fully grown male, but less than 50 years old when he died. So what did Dragon Man look like when he was alive? We don’t know how tall he was or his overall build, although from the other Denisovan bones we have, we know Denisovans were a strong, robust people, similar to Neanderthals, and were more closely related to Neanderthals than humans. Dragon Man would have had a pronounced brow that would probably make his eyes look deep-set, and a large nose but a receding chin. Genetic markers indicate he probably had dark hair and eyes, and a medium shade of skin. If you had a time machine and could go back and meet Dragon Man when he was alive, you’d know at a glance that he wasn’t a Homo sapiens but he would probably look pretty normal in most respects. One exciting note is that paleoanthropologists now think that three other ancient skulls from China may actually be Denisovan skulls. With luck they’ll be able to extract genetic material from them soon so we can learn more about our ancient cousins. You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at [email protected]. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes. Thanks for listening!