A number of bones and teeth belonging to species, named Homo luzonensis by scientists and dating back to around 50,000 years ago, have been discovered on the island of Luzon in the Philippines.
One scientist, Professor Chris Stringer, from the National History Museum, said: "After the remarkable finds of the diminutive Homo floresiensis were published in 2004, I said that the experiment in human evolution conducted on Flores could have been repeated on numerous other islands in the region".
The fossil bones and teeth found about 3 meters (9.8 feet) below the ground in the cave show they belonged to small-bodied people.
Other excavations on Luzon suggest the more modern hominin species, the Denisovans, also called the Philippine island home.
The Indonesian island of Flores was home to a species called Homo floresiensis, nicknamed The Hobbits due to their small stature. Basically, the newly discovered species is a mix of both older and more recent types of human in terms of physical features. Bones of deer and related animals were found in the area, some with cut marks, suggesting they were butchered although there were no stone tools or sharp implements found in the immediate area where the human fossils were dug up, Mijares said. Although some of the characteristics can be compared to Homo erectus and Homo sapiens, the teeth and jaw features remain distinct as far as the odd features they combine.
Florent Détroit, of the Natural History Museum in Paris and the paper's first author, also said the discovery provided the latest challenge to the fairly straightforward prevalent narrative of human evolution.
If it took rare luck for ancient hominins to reach these islands, it might help explain why these island hominins looked so different from other human species. "We are now one of the regional centers for human evolutionary research", Mijares said.
Michael Petraglia of the Max Planck Institute for the Science of Human History in Jena, Germany, said the Luzon find "shows we still know very little about human evolution, particularly in Asia".
It remains uncertain who the ancestors of Homo luzonensis and Homo floresiensis were. "DNA preservation in these tropical environments is not good, but it's possible that a scrap of bone you can't even tell as hominin could preserve their DNA perfectly", Tocheri said.
"We completed the comparisons and analyses, and it confirmed that this was something special, unlike any previously described species of hominins in the homo genus", added Detroit, a palaeoanthropologist at France's Musee de l'Homme.
The "remarkable discovery. will no doubt ignite plenty of scientific debate over the coming weeks, months and years", said Matthew Tocheri, associate professor of anthropology at Canada's Lakehead University, in a review commissioned by Nature. But other researchers have argued that the Hobbits were descended from Homo erectus but that some of their anatomy reverted to a more primitive state.