Archaeology of the Flores Man Site: Liang Bua Cave, Indonesia

By K. Kris Hirst

Liang Bua is located in the Wae Racang Valley on the western end of the tiny island of Flores in Indonesia. Liang Bua is the name of the karst limestone cave from which Flores Man (a.k.a. the Hobbit) was found. The stratified site deposits are 12 meters in depth, and within the deposits have been found both modern humans and the hominin remains somewhat controversially called "Homo floresiensis".

Liang Bua Cave Formation

The cave was created by karst action nearly 400,000 years ago, but evidence suggests that it was invisible from the surface until about 190,000 years ago. Homo erectus appears on Flores Island beginning 840,000 years ago. Homo sapiens first appeared in the region circa 55,000-35,000 years ago.

Liang Bua's Hominin Remains

Hominin remains recovered from the site include LB1 (the original Flores Man, dated ca 18,000 years old), and elements from eight other individuals (dated between 12,000 years and 95,000 years ago. Modern human skeletal remains recovered from Liang Bua are all within Holocene levels (i.e., within the past 11-12,000 years or so). None of the bones recovered from Pleistocene deposits in Liang Bua cave appear to be modern H. sapiens.

Artifact Assemblages at Liang Bua

The artifact assemblages from Liang Bua include a fairly sophisticated suite of stone tools attributed to H. floresiensis, particularly within a level dated to ca. 74,000 years ago (+14/-12 ka) that contains stone artifacts with evidence of hard-hammer stone tool production. Raw material for the stone tools was mostly volcanic glass, with some marine limestone. The reconstructed stone tool manufacturing process is similar to sites of the same age found throughout Southeast Asia: a combination of off-site production of large stone blanks and on-site blank reduction. These methods were used by all hominids in southeast Asia around at the time: H. erectus, H. sapiens, and (assuming Flores is a separate species) H. floresiensis.

Sources

Argue, Debbie, Denise Donlon, Colin Groves, and Richard Wright. 2007. Homo floresiensis: Microcephalic, pygmoid, Australopithecus, or Homo? Journal of Human Evolution 51(4):360-374.
Brown, Peter, T. Sutikna, M. J. Morwood, R. P. Soejono, Jatmiko, E. Wayhu Saptomo & Rokus Awe Due. 2004 A new small-bodied hominin from the Late Pleistocene of Flores, Indonesia. Nature 431:1056–1061
Morwood, Michael J. et el. 2004. Archaeology and age of a new hominin from Flores in eastern Indonesia. Nature 431:1087–1091
Morwood, Michael J., et al. 2005. Further evidence for small-bodied hominins from the Late Pleistocene of Flores, Indonesia. Nature 437:1012-1017.
Westaway, K.E., M.J. Morwood, R.G. Roberts, J.-x. Zhao, T. Sutikna, E.W. Saptomo and W.J. Rink. 2007. Establishing the time of initial human occupation of Liang Bua, western Flores, Indonesia. Quaternary Geochronology: in press
Read More..

Fossil Finds of Flores Man, Indonesia

By K. Kris Hirst

The scientific world was rocked by reports of the discovery of the preserved skeleton of a previously unknown hominin species in 2004. Tentatively named Homo floresiensis, or Flores Man, the hominin became known to the world press as the Little Lady of Flores or the Hobbit. Most of a female individual of Flores Man was discovered by a joint international research team led by R.P Soejono from the Indonesia Centre for Archaeology and Michael Morwood from the University of New England Armidale. The research team discovered Flores Man six meters deep within the deposits of the Liang Bua site, a limestone cave on the island of Flores in Indonesia. The hominin was very small in stature, no more than a meter in height and as small as those of the shortest human beings ever known, but the brain capacity of the creature was much smaller than in modern humans. Further, the form of the skull and lower skeleton suggested to Soejono, Morwood and colleagues that the Little Lady was a form of Homo erectus, and not Homo sapiens. Flores Man caused quite a stir, not the least because she appeared to have survived as recently as 18,000 years ago, far later than any other Homo erectus known on the planet.


H. floresiensis skull, Liang Bua Cave, Indonesia. (by Peter Brown)

The resultant furor over the original Flores Man findings brought a competing theory, not yet published, that the skeleton is of a microcephalic (diseased) modern human pygmy. Further problems developed when the skeletal material was damaged during analysis by another researcher.

Morwood and colleagues continued excavations in Liang Bua cave through 2004, and discovered partial remains of eight additional individuals, one a subadult. These new finds were reported in the journal Nature on October 13, 2005. The recovery of so many examples has allowed for a more complete consideration of the form of H. floresiensis as a group, rather than the single individual. All of the specimens (with the exception of the child) appear to have been about 1 meter in height. In general, the skull shape and body form are most similar to Homo erectus, but H. floresiensis has longer arms and a smaller brain capacity than H. erectus normally has, in fact closer to Australopithecus or gorilla than H. erectus. Recent investigations of the Dmanisi H. erectus fossils in Georgia and those at Olduvai in Kenya suggest that there was more diversity in H. erectus than has been previously identified, a fact surely epitomized here.


Comparison of mandibles from Laetoli Australopithecus afarensis LH4 and Homo floresiensis LB6. (by Nature)

Further information was also found about the behavior of the little hominin: butchered pygmy Stegodon (a primitive type of elephant) and Komodo dragon have been found at Liang Bua, as have clusters of fire-cracked rock and charred bone in levels containing H. floresiensis skeletal materials, suggesting the hominin knew how to control fire. Stone tools recovered from the site evidence a sophisticated grasp of lithic knapping.


Homo floresiensis (Liang Bua Cave, Indonesia) and a modern human skull. (by Peter Brown)

The late date of the appearance of H. floresiensis is also confirmed. Using thermo-luminescence dating of the strata in which the skeletons lie, the oldest appear to have been dated to about 94,000 years ago, and the most recent 12,000 years ago. None of these materials are fossilized, and DNA testing and radiocarbon dating of the hominid skeletons themselves does not seem to be possible, given the condition of the material. Morwood hopes that additional skeletal materials may allow these forms of testing.

Whatever species the little hominin is, Homo erectus or something quite different, they are certainly not human. The appearance of a different hominin species dated to 12,000 years ago is quite remarkable, given that the last known Homo erectus found to have been living on planet earth died out about 120,000 years ago; and the most recent Neanderthal form of Homo sapiens was gone by 28,000 years ago.

Sources and Furthern information

Read the latest information about the Flores individual: Is Flores a Deformed Homo sapiens?
Lieberman, Daniel E. 2005 Further fossil finds from Flores. Nature 437(October 13, 2005):957-958.
Morwood, M. J., et al. 2004 Archaeology and age of a new hominin from Flores in eastern Indonesia. Nature 431:1087-1091.
Morwood, Michael J., et al. 2005 Further evidence for small-bodied hominins from the Late Pleistocene of Flores, Indonesia. Nature 437(13 October 2005):1012-1017.
Read More..