New fossils help case for ‘Hobbit’ species
Scientists unsure about origin without the rest of skeleton
Scientists digging in a cave on the Indonesian island of Flores years ago, found a tiny humanlike skull, then a pelvis, jaw and other bones, all between 60,000 and 100,000 years old.
The fossils, the scientists concluded, belonged to individuals who stood just 3 feet tall — an unknown species, related to modern humans, that they called Homo floresiensis or, more casually, the hobbits.
On Wednesday, researchers reported that they had discovered still older remains on the island, including teeth, a piece of a jaw and 149 stone tools dating back 700,000 years. The finding suggests that the ancestors of the hobbits arrived on Flores about a million years ago, the scientists said, and evolved into their own distinct branch of the hominin tree.
But without other parts of a skeleton, such as the skull, hands or feet, they can’t be sure whether the newly discovered fossils also belong to Homo floresiensis or to some other ancient relative of humans (known generally as hominins).
“We have to be careful,” said Gert van den Bergh, a paleontologist at the University of Wollongong in Australia and a co-author of the new study. “Until we find those elements, we cannot really say much more about it.”
Van den Bergh and his colleagues found the new fossils at Mata Menge, an archaeological site on Flores that had already yielded stone tools dating back 800,000 years — a clue that hominins of some sort had once lived there.
Starting in 2004, the researchers chiseled fossils out of the cementlike rock. For years, they found only animal fossils, including dwarf elephants.
In 2014, van den Bergh and his colleagues got their first stroke of good luck: six feet below the surface, they found a cracked molar. Very quickly they discovered six other teeth, as well as a piece of a jaw. The fossils come from three hominins.
The researchers were intrigued to find a wisdom tooth erupting from the jaw. “That means that it was an adult,” van den Bergh said.
Yet this adult must have been very small. The researchers estimate the jawbone was 23 percent smaller than the Homo floresiensis jaw found at Liang Bua.
“They were truly little people, smaller even than the Liang Bua hobbits,” said Richard Roberts of the University of Wollongong.
Critics have argued that the Liang Bua bones might have come from a member of our own species who suffered some kind of growth disorder, such as Down syndrome. Several experts agreed that the Mata Menge fossils put to rest any doubts that Homo floresiensis is its own distinct species.
In another study published Wednesday in the journal PLOS One, Karen L. Baab, a paleoanthropologist at Midwestern University in Glendale, Ariz., and her colleagues compared skeletons of people with Down syndrome with the Liang Bua fossils. The researchers concluded that any resemblance was superficial, and that the fossils belonged to a separate species.
“There continues to be no very good evidence that this is a pathological modern human,” Baab said.
Van den Bergh is optimistic that he and his colleagues will find a skull and other bones at Mata Menge that may satisfy the critics. The layer of rock where they found the hominin teeth and jaw is chock-full of fossils from other species.
The geology of the rock indicates that the fossils come from a streambed that was suddenly buried in mudslides from a nearby volcanic eruption. The disaster seems to have claimed a number of victims at once — including, possibly, more hobbits.
“I’m sure we will find more stuff,” van den Bergh said.