Denisovan Leg Bones Suggest They Towered Over Homo Erectus
Denisovans remain one of the most mysterious branches of the human family tree, known mostly from a handful of scattered fossils and traces of DNA still carried by people alive today. A new study based on two fossilized leg bones is now offering something rare: a sense of how physically imposing at least some of these ancient cousins may have been.
An Elusive Branch of the Human Family Tree
Closely related to both modern humans and Neanderthals, Denisovans were a group of hominins who lived across Asia from roughly 400,000 to about 30,000 years ago. First identified in 2010 from a finger bone found in Siberia’s Denisova Cave, the species has remained frustratingly difficult to study ever since, with only a handful of additional fossils surfacing in the years since that initial discovery.
New research based on Denisovan leg bones suggests at least some individuals were relatively large. The findings were published August 8 on the preprint server bioRxiv and have not yet undergone peer review, meaning the conclusions are still preliminary and subject to further scrutiny before they become part of the accepted scientific record.
Fishermen’s Bones From the Penghu Channel
The study is based on fossilized leg bones from two Denisovan individuals, known as Penghu 2 and Penghu 3, who lived between roughly 45,000 and 43,000 years ago. The femur and tibia bones were originally recovered by fishermen from the Penghu Channel, a strait between Taiwan and mainland China, and eventually found their way into the collection of the National Museum of Natural Science in Taiwan.
Based on their analysis, researchers believe both individuals were male. In life, they estimate Penghu 2 weighed around 183 pounds and stood nearly 5 feet 11 inches tall. Penghu 3 appears to have been even larger, at roughly 200 pounds and standing more than 6 feet 2 inches tall.
Towering Over Their Neighbors
Those estimates would mean Penghu 2 and Penghu 3 likely towered over other hominins living in the same region around the same time, including Homo erectus. According to the researchers, these Denisovans may have stood as much as nearly a foot taller and weighed more than 60 pounds more than the smaller-bodied Homo erectus populations they shared the landscape with.
“Big and imposing humans” is how Adam Brumm, an archaeologist at Griffith University who was not involved in the research, described the pair to New Scientist. Brumm offered a memorable modern comparison for Penghu 3’s build specifically, noting that in size the individual would have roughly matched Norwegian footballer Erling Haaland, whose profile rose sharply during this year’s World Cup.
Why Size May Have Mattered
A large build fits with what scientists already suspect about Denisovan life. Their substantial size may have given them an advantage hunting elephants and other large game, as well as covering long distances on foot in search of food, according to Brumm.
He also offered a candid take on what that size might have meant for early encounters between species. Given a choice between running into a Denisovan from Taiwan or one of the diminutive “hobbits” of Flores, known formally as Homo floresiensis, Brumm said he would much rather come face to face with the smaller of the two.
Surprisingly Human-Like Features
Beyond sheer size, the analysis turned up an unexpected anatomical detail. The Denisovan leg bones showed a well-developed, vertical ridge on the thigh bone known as a pilaster, a feature that reads as surprisingly human-like. Researchers speculate this trait might reflect an adaptation suited to an active, on-the-go lifestyle, or it could potentially have been inherited through interbreeding with Homo sapiens.
That interbreeding hypothesis is not far-fetched. Many people alive today carry small amounts of Denisovan DNA, and researchers suspect Homo sapiens and Denisovans may have interbred more than once throughout their overlapping history. Still, without genomic data recovered directly from these particular fossils, the researchers stress that the idea remains a hypothesis rather than a confirmed conclusion.
Filling a Major Gap in the Map
John Hawks, an anthropologist at the University of Wisconsin-Madison who was not involved in the study, called it a fascinating set of findings, and pointed to its significance beyond questions of stature alone. Fossil evidence of Denisovans has previously turned up in Russia and Tibet, but coverage of the wider region has remained sparse.
“In the coastal region and river valleys of China, and in mainland Southeast Asia, there is almost no information about them,” Hawks told IFLScience, adding that there is also no information available on later Denisovans from island Southeast Asia. As a result, researchers have had little sense of what Denisovans in these regions actually looked like or how they lived.
Even as a preliminary, not-yet-peer-reviewed study, the 45,000-year-old leg bones from the Penghu Channel carry outsized significance simply because they offer the first substantial information researchers have from this time period across a large and previously blank stretch of the Denisovan map.
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