Liang Bua in brief
Liang Bua (“cool cave” in the local Manggarai language) is a large limestone cave on the Indonesian island of Flores, east of Bali. Its floor holds layers of sediment about 190,000 years deep, with stone tools and bones of animals and people. In 2003 a team found there the skeleton of a tiny adult, which in 2004 was named as a new species, Homo floresiensis.
Discovery
An Indonesian-Australian team led by the archaeologists Radien Soejono and Mike Morwood excavated at Liang Bua, looking for evidence of early modern humans moving through the islands toward Australia. In September 2003, at a depth of about six metres, they uncovered a skeleton that they called LB1. It was a woman who stood about 1.06 metres (3 ft 6 in) tall, with a brain of only about 380 cubic centimetres, similar to a chimpanzee’s, yet found with stone tools. They announced the find in Nature in October 2004, and the press called her the “Hobbit”.
The skeleton had a number of unusual features: a very small brain and body, a short thigh bone, a wrist that looked primitive, and a long, flat foot. Bones of at least a dozen other individuals were found later.
How old?
At first the skeleton was dated to about 18,000 years ago, which would have made them alive when modern humans were already in Asia. In 2016 a re-examination of the layers found that LB1 was older: the bones are between about 100,000 and 60,000 years old (some sources give up to 50,000), and stone tools linked to the species date from about 190,000 to 50,000 years ago. The species then seems to have vanished about the time modern humans arrived on the island, around 46,000 years ago, though the reason is unknown.
An argument about what they were
Some researchers argued that LB1 was a modern human with a disease that made the head small, such as microcephaly. Further studies of more bones, which repeat the unusual features, suggest that they are a distinct species. In the view of most researchers today, Homo floresiensis was a real species of small human, probably descended from an earlier human who reached the island and became smaller over time, a pattern called island dwarfism that is seen in many animals. Others think it might be descended from a species older than Homo erectus, perhaps Homo habilis.
Some insights come from another site on Flores, Mata Menge, where in 2016 a team found a lower jaw and teeth of a small human about 700,000 years old, possibly an early form of the Hobbit, with stone tools about a million years old, meaning people were on the island long before floresiensis.
Life on Flores
Liang Bua is also rich in animal bones. The people lived with giant rats, huge marabou storks, Komodo dragons and Stegodon, a small, extinct relative of elephants, that they probably hunted. They made stone tools and used fire. Local legends of “ebu gogo”, small hairy people, are sometimes linked to them, but the stories are more recent.
Why it matters
Liang Bua shows that a small-brained human species survived for a long time and until a much later date than expected, and that human evolution included more branches than previously thought. In 2019 another small human, Homo luzonensis, was reported from Callao Cave in the Philippines, so the island pattern may have been repeated.
Visiting
The cave is a research site and access is controlled, so check locally before planning a visit. The fossils are kept in Indonesia, in Jakarta.
Sources
- Brown, P. and others (2004). A new small-bodied hominin from the Late Pleistocene of Flores, Indonesia. Nature 431: 1055 to 1061.
- Sutikna, T. and others (2016). Revised stratigraphy and chronology for Homo floresiensis at Liang Bua in Indonesia. Nature 532: 366 to 369.
- van den Bergh, G. D. and others (2016). Homo floresiensis-like fossils from the early Middle Pleistocene of Flores. Nature 534: 245 to 248.
- Détroit, F. and others (2019). A new species of Homo from the Late Pleistocene of the Philippines. Nature 568: 181 to 186.