Denisovan

The Denisovans or Denisova hominins are archaic humans in the genus "Homo". They may be an extinct species or subspecies. 
They were first discovered in in the Denisova Cave in the Altai Mountains in Siberia. This cave that has also been lived in by Neanderthals and modern humans. 
A finger bone fragment of a juvenile female was discovered. She lived about 41,000 years ago, with about 3% to 5% of the DNA of Melanesians and Aboriginal Australians and around 6% in Papuans deriving from Denisovans.
The mitochondrial DNA (mtDNA) of the finger bone showed it was genetically distinct from Neanderthals and modern humans. The nuclear genome from this specimen suggested that Denisovans shared a common origin with Neanderthals. 
DNA analysis has indicated that modern humans, Neanderthals, and the Denisova hominin last shared a common ancestor around years ago.
The mtDNA analysis also suggested that this species was the result of a migration out of Africa that came between a migration by "Homo erectus" individuals and later ones by some ancestors of most modern humans.
Fossils.
So far, the fossils of four distinct Denisovans from Denisova Cave have been identified through their DNA: Denisova 2, Denisova 3, Denisova 4, and Denisova 8. Denisova 2 and Denisova 3 are young females,and Denisova 4 and Denisova 8 are adult males. 
Anatomy.
So far, only a finger bone, a toe bone and two teeth are the only body parts that have been found.  The finger bone is from a woman.  It is broader than a human finger.  This fact suggests that Denisovans were more robust than any modern humans.
Mitochondrial DNA analysis.
The mtDNA from the finger bone differs from that of modern humans by 385 nucleotides in the mtDNA strand out of approximately 16,500. This  is more than the difference between modern humans and Neanderthals, which is around 202 bases.