Ancient humans rampantly indulged in interspecies sex in a Lord Of The Rings-type world of different  human groups, new DNA analysis has revealed. And our ancient bedfellows appear to have included a 'mystery human ancestor', which has not yet been identified. Genome analysis from a Neanderthal and another group of ancient humans, the Denisovans, was presented to a meeting of the Royal Society in London, and it included 'snippets' of  the mystery DNA  - neither human nor Neanderthal. It suggests that interbreeding was rampant and more widespread between the human-like groups living in Europe and Asia more than 30,000 years ago than previously thought, scientists say.
@highlight
Genome analysis of Neanderthal and human-like group called Denisovans
@highlight
It reveals  ancient bedfellows may have included 'mystery human ancestor'
@highlight
Has been likened to Lord Of The Rings world of creatures which interbred
Research increasingly seems to indicate that our close cousins, the @placeholder, were much more similar to us than imagined.