This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Take a walk in London's Trafalgar Square this summer, and people of all body sizes—some tall, some short—will be wilting in the heat: a real mix of sizes. Picking just two from the crowd to represent the whole human species would be a tall order.
But that is exactly what we do when we find fossils of ancient hominins (human relatives). Anthropologists can estimate a person's height with reasonable accuracy from long bones—your femur (thigh bone) works well. On average, the size of these bones scales well with overall height, given a large sample of bones.
This is exactly what a group of scientists have done using fossils dredged from the seafloor off Taiwan. To add to the mystery, these bones are those of Denisovans, currently one of the most enigmatic species of hominins. The Denisovans were a widespread species of Homo (the genus that encompasses our own species, as well as close relatives such as Neanderthals).
They were initially known only from genetic sequences extracted from isolated fragments of material, such as a small finger bone, at Denisova Cave in the Altai Mountains of Siberia. The apparent absence of substantial fossil material from this species made them mysterious, although fresh discoveries in recent years have added to our understanding. These include the Dragon Man (or Harbin) skull, recovered from a river in northeast China.
DNA and protein analysis has now linked this large skull to the Denisovans. The remarkable feature of the fossils analyzed by Yousuke Kaifu, from the University of Tokyo, and colleagues is that they were dredged from the Penghu Channel in the Taiwan Strait. Most rare hominin fossils are carefully excavated, allowing researchers to record their exact position within layers of sediment and their relationship to associated animals, artifacts and environmental evidence.
These bones were instead recovered from the seabed among the fossilized remains of terrestrial ice age mammals, probably deposited when sea levels exposed the channel as dry land around the time when the ice age was at its height. Their precise discovery locations and geological contexts were not recorded. This makes the fossils scientifically unusual: Their anatomy and preserved proteins contain valuable evidence.
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