Researchers have found 700,000-year-old remains on the Indonesian island of Flores, apparently belonging to ancestors of an infamous 'Hobbit' species discovered there back in 2003.
They say it proves once and for all the tiny Homo floresiensis people were a distinct species of human, and not a community of deformed Homo sapiens as some have claimed.
The 2003 Homo floresiensis remains belonged to people living sometime between 50,000 and 100,000 years ago, much more recent than the new fossils -- a lower right jaw fragment and six teeth from at least one adult and two children, found in layers of sedimentary rock at a site named Mata Menge.
"This find has important implications for our understanding of early human dispersal and evolution in the region, and quashes once and for all any doubters that believe Homo floresiensis was merely a sick modern human," says reasearch team leader Dr Gert van den Bergh of the University of Wollongong.
"All the fossils are indisputably hominin and they appear to be remarkably similar to those of Homo floresiensis," says Dr Yousuke Kaifu, from Tokyo's National Museum of Nature and Science.
"The morphology of the fossil teeth also suggests that this human lineage represents a dwarfed descendant of early Homo erectus that somehow got marooned on the island of Flores."
A tooth belonging to an ancestor of Homo floresiensis (supplied)
What the fossils show is that the inhabitants of Flores were already small 700,000 years ago, long before 2003's 'Hobbit' discovery.
"It is conceivable that the tiny Homo floresiensis evolved its miniature body proportions during the initial 300,000 years on Flores, and is thus a dwarfed side lineage that ultimately derives from Homo erectus," says Dr van den Bergh.
"It is also possible that this lineage pre-dates the first hominin arrival on Flores, implying speciation occurred on a stepping-stone island between Asia and Flores, such as Sulawesi."
Speciation is the evolution of a new species, usually when a group becomes isolated from others.
The next step for the team is looking into older rock, dating back 1 million years, to see if they can find full-sized examples of Homo erectus to confirm the theory.
The research is published today in journal Nature.