WASHINGTON (Reuters) – Tiny pre-humans who lived on an Indonesian island until about 12,000 years ago had brains so surprisingly sophisticated that the creatures may represent a previously unrecognized species of early humans, or hominids, scientists reported on Thursday.
CAT scans of the inside of a skull — among the bones of eight individuals found in a cave on the Indonesian island of Flores — suggest brains that would have allowed advanced behavior such as toolmaking, the international team of researchers said.
They said further study of the skull of the creature, nicknamed “the Hobbit” after a literary character, showed it clearly was a normal adult of its species, not a mutant or diseased specimen, as some critics have alleged.
“I am bowled over,” said Dean Falk of Florida State University, who studied CAT scans to make a virtual cast of the inside of the creature’s skull.
“I thought we were going to see a little chimpanzee-like brain and I was wrong. Nothing like this has been seen before,” she told a telephone briefing.
Falk saw features that would have allowed the “Hobbit” to have made the tools found in the Indonesian cave, to use fire and to hunt as a group.
“I never thought I would see it in a brain this small,” she said.
Homo floresiensis stood only about 3 feet (one meter) tall and had a brain about a third the size of modern adult humans. It had long arms and would have walked upright.
“We know from the record that these little humans, these little meter-high humans, were hunting things like pygmy elephants, were making fire and were making stone tools,” said Mike Morwood of the University of New England in Australia, who led the initial mission that uncovered the bones.
NOT A DWARF
The discovery, announced last October, was met with surprise and some skepticism. Critics said the bones in fact represented some sort of dwarf or perhaps something suffering from a condition called microcephaly and not a unique species of early human.
But, writing in the journal Science, the team of U.S., Australian and Indonesian researchers said their unusual study of the inside of the “Hobbit’s” brain case showed it was related to Homo erectus, which lived from 2 million years ago to about 25,000 years ago.
“However, it was not like a little miniature Homo erectus brain. It was different,” Falk said.
The particular skull discovered on Flores had clear impressions left by the creature’s brain that allowed Falk and experts at Washington University in St. Louis to trace important structures.
For instance, there are two expanded areas in the frontal lobe, Falk said. “I have not seen anything like this before,” said Falk, who compared “Hobbit’s” skull to images of 10 human skulls, 18 chimpanzee skulls and five Homo erectus skulls.
“In humans this is a relatively large area,” she said. “It is known to be involved in planning ahead.”
Hobbit had “fat” temporal lobes, she said. “People don’t have fat ones but big ones,” she said.
“In humans the left temporal lobe has things that are important for understanding speech. The temporal lobe also some memory function. It processes emotions. It is important for identifying objects and people and putting names to people and objects.”
Especially interesting was a fissure near the back of the Hobbit’s brain that Falk’s team identified as a lunate sulcus, a structure seen in humans that is pushed forward because of an expanded association cortex.
It shows the little pre-humans were tiny but not stupid. “I almost fell over seeing this feature in something so small,” Falk said.