Scientists at the Germany-based Max Planck Institute for Evolutionary Anthropology said they were able to sequence the genome of a Denisovan using DNA extracted from less than 10 milligrams of the finger bone.
Fossils of the Denisovans -- an extinct group closely related to the Neanderthals -- were discovered in southern Siberia in 2008.
A year ago, researchers published the first rough draft of the genome of an archaic girl who lived in Denisova Cave, Siberia, at least 30,000 years ago.
"The genome is of very high quality," said Matthias Meyer, who developed the techniques that made the technical feat possible.
The group plans to present a paper describing the genome later this year.
"But we want to make it freely available to everybody already now," said Svante Paabo, director of the Department of Genetics at the Max Planck Institute. "We believe that many scientists will find it useful in their research."