Smallest Arm Bone Fossil Ever Found Sheds Light On Flores 'hobbits'

WELLINGTON, Aug 7 (Bernama-dpa) -- Scientists have discovered rare early human fossils from the Indonesian island of Flores, a study published on Wednesday has revealed, reported the German news agency (dpa).

The fossils included an "astonishingly small" adult limb bone, dated to about 700,000 years old.

It is thought to be from a very early individual of the "hobbit" species Homo floresiensis, that were uncovered in 2003 at Liang Bua cave in the island's west.

Pre-dating the Liang Bua hominins by 650,000 years, the latest fossil finds belong to at least three individuals with smaller jaws and teeth than Homo floresiensis.

The study, published in Nature Communications, says the recovery of a fossil limb bone provided a wealth of evidence regarding the ancestral origin of Homo floresiensis.

Based on the estimated length of the bone, scientists calculated the body height of this hominin to be about 100 centimetres tall, about 6 centimetres shorter than the estimated body height of the skeleton from Liang Bua.

"This 700,000-year-old adult humerus is not just shorter than that of Homo floresiensis, it is the smallest upper arm bone known from the hominin fossil record worldwide," said co-author Adam Brumm from Griffith University's Australian Research Centre for Human Evolution.

"This very rare specimen confirms our hypothesis that the ancestors of Homo floresiensis were extremely small in body size; however, it is now apparent from the tiny proportions of this limb bone that the early progenitors of the 'Hobbit' were even smaller than we had previously thought."

Two teeth recovered at the site were also small in size and one bore shape characteristics consistent with early Homo erectus of Java. This similarity did not support the hypothesis that Homo floresiensis evolved from an earlier and more primitive type of hominin, scientists said.

"The evolutionary history of the Flores hominins is still largely unknown," Brumm said. 

"However, the new fossils strongly suggest that the 'Hobbit' story did indeed begin when a group of the early Asian hominins known as Homo erectus somehow became isolated on this remote Indonesian island, perhaps one million years ago, and underwent a dramatic body size reduction over time."

-- BERNAMA-dpa