The picture of these enigmatic hominids began to come into view this year

Denisovans’ days of Stone Age obscurity appear numbered. The mysterious “ghost clan” floated into view over a decade ago, when a bit of a girl’s pinkie bone, found in Siberia’s Denisova Cave, yielded DNA that didn’t match that of any known hominid. A few more fossils — three teeth and a limb fragment — plus genetic analyses indicated Denisovans were close relatives and occasional mating partners of Neandertals and Homo sapiens tens of thousands of years ago. But there was too little evidence to say what Denisovans looked like or how they behaved.

Discoveries reported in 2019 brought Denisovans into focus — but left plenty of room for interpretation. As fossils accumulate, investigators will grasp how Denisovan anatomy influenced the skeletal makeup of its mating partners in the Homo genus. Thanks to Denisovan discoveries, “we can now see that hybridization contributed to our own origins,” says paleoanthropologist John Hawks of the University of Wisconsin–Madison.

Ancient DNA evidence reported this year suggests that Denisovans fanned out into three genetically separate lines that mated with various human groups in Asia. That finding played into an emerging view of human evolution as a braided stream, with closely related species flowing into and out of genetic exchanges.

But testing that possibility requires finding more Denisovan fossils. The discovery of two pieces of a skull in the Siberian cave, reported this year, gave a glimpse of the anatomy that the ghost clan brought to the ancient hybridization scene (SN: 4/27/19, p. 15). The bone’s surprising thickness recalls H. erectus — a species dating back at least 1.8 million years. Yet a newly identified chunk of the girl’s finger bone looks like people’s digits today (SN: 9/28/19, p. 14).

These findings fit with the idea that Denisovans had a mix of their own skeletal traits plus characteristics like those of their breeding partners. That theme also emerged from a project that used the Denisovan girl’s DNA to reconstruct her skeleton and face (SN: 10/12/19 & 10/26/19, p. 24). The youngster’s portrait, which some researchers regard as too speculative, included a relatively flat, humanlike face but, like Neandertals, no distinct chin. Her broad nose had a look all its own.

With few fossils to go on, researchers reconstructed Denisovan skeletal anatomy based on an analysis of ancient DNA. A 3-D printed reconstruction of a female Denisovan is shown here.Maayan Harel