E. Wahyu Saptomo

Further evidence for small-bodied hominins from the Late Pleistocene of Flores, Indonesia

Homo floresiensis was recovered from Late Pleistocene deposits on the island of Flores in eastern Indonesia, but has the stature, limb proportions and endocranial volume of African Pliocene Australopithecus. The holotype of the species (LB1), excavated in 2003 from Liang Bua, consisted of a partial skeleton minus the arms. Here we describe additional H. floresiensis remains excavated from the cave in 2004. These include arm bones belonging to the holotype skeleton, a second adult mandible, and postcranial material from other individuals. We can now reconstruct the body proportions of H. floresiensis with some certainty. The finds further demonstrate that LB1 is not just an aberrant or pathological individual, but is representative of a long-term population that was present during the interval 95–74 to 12 thousand years ago. The excavation also yielded more evidence for the depositional history of the cave and for the behavioural capabilities of H. floresiensis, including the butchery of Stegodon and use of fire.

The primitive wrist of Homo floresiensis and its implications for hominin evolution

Whether the Late Pleistocene hominin fossils from Flores, Indonesia, represent a new species, Homo floresiensis, or pathological modern humans has been debated. Analysis of three wrist bones from the holotype specimen (LB1) shows that it retains wrist morphology that is primitive for the African ape-human clade. In contrast, Neandertals and modern humans share derived wrist morphology that forms during embryogenesis, which diminishes the probability that pathology could result in the normal primitive state. This evidence indicates that LB1 is not a modern human with an undiagnosed pathology or growth defect; rather, it represents a species descended from a hominin ancestor that branched off before the origin of the clade that includes modern humans, Neandertals, and their last common ancestor.

Revised stratigraphy and chronology for Homo floresiensis at Liang Bua in Indonesia

Homo floresiensis, a primitive hominin species discovered in Late Pleistocene sediments at Liang Bua (Flores, Indonesia), has generated wide interest and scientific debate. A major reason this taxon is controversial is because the H. floresiensis-bearing deposits, which include associated stone artefacts and remains of other extinct endemic fauna, were dated to between about 95 and 12 thousand calendar years (kyr) ago. These ages suggested that H. floresiensis survived until long after modern humans reached Australia by ~50 kyr ago. Here we report new stratigraphic and chronological evidence from Liang Bua that does not support the ages inferred previously for the H. floresiensis holotype (LB1), ~18 thousand calibrated radiocarbon years before present (kyr cal. bp), or the time of last appearance of this species (about 17 or 13–11 kyr cal. bp). Instead, the skeletal remains of H. floresiensis and the deposits containing them are dated to between about 100 and 60 kyr ago, whereas stone artefacts attributable to this species range from about 190 to 50 kyr in age. Whether H. floresiensis survived after 50 kyr ago—potentially encountering modern humans on Flores or other hominins dispersing through southeast Asia, such as Denisovans—is an open question.

Craniofacial morphology of Homo floresiensis: description, taxonomic affinities, and evolutionary implication.

This paper describes in detail the external morphology of LB1/1, the nearly complete and only known cranium of Homo floresiensis. Comparisons were made with a large sample of early groups of the genus Homo to assess primitive, derived, and unique craniofacial traits of LB1 and discuss its evolution. Principal cranial shape differences between H. floresiensis and Homo sapiens are also explored metrically. The LB1 specimen exhibits a marked reductive trend in its facial skeleton, which is comparable to the H. sapiens condition and is probably associated with reduced masticatory stresses. However, LB1 is craniometrically different from H. sapiens showing an extremely small overall cranial size, and the combination of a primitive low and anteriorly narrow vault shape, a relatively prognathic face, a rounded oval foramen that is greatly separated anteriorly from the carotid canal/jugular foramen, and a unique, tall orbital shape. Whereas the neurocranium of LB1 is as small as that of some Homo habilis specimens, it exhibits laterally expanded parietals, a weak suprameatal crest, a moderately flexed occipital, a marked facial reduction, and many other derived features that characterize post-habilis Homo. Other craniofacial characteristics of LB1 include, for example, a relatively narrow frontal squama with flattened right and left sides, a marked frontal keel, posteriorly divergent temporal lines, a posteriorly flexed anteromedial corner of the mandibular fossa, a bulbous lateral end of the supraorbital torus, and a forward protruding maxillary body with a distinct infraorbital sulcus. LB1 is most similar to early Javanese Homo erectus from Sangiran and Trinil in these and other aspects. We conclude that the craniofacial morphology of LB1 is consistent with the hypothesis that H. floresiensis evolved from early Javanese H. erectus with dramatic island dwarfism. However, further field discoveries of early hominin skeletal remains from Flores and detailed analyses of the finds are needed to understand the evolutionary history of this endemic hominin species.

Brief communication: "Pathological" deformation in the skull of LB1, the type specimen of Homo floresiensis.

If the holotype of Homo floresiensis, LB1, suffered from a severe developmental pathology, this could undermine its status as the holotype of a new species. One of the proposed pathological indicators that still remains untested is asymmetric distortion in the skull of LB1 (Jacob et al.: Proc Natl Acad Sci USA 103 (2006) 13421-13426). Here, we present evidence that LB1 exhibits antemortem craniofacial deformities that are consistent with posterior deformational (positional) plagiocephaly. This is a relatively common condition in modern people with no serious associated health problems and does not represent a severe developmental abnormality in LB1.

The type specimen (LB1) of Homo floresiensis did not have Laron syndrome.

The type specimen (LB1) of Homo floresiensis has been hypothesized to be a pathological human afflicted with Laron Syndrome (LS), a type of primary growth hormone insensitivity (Hershkovitz et al.: Am J Phys Anthropol 134 [2007] 198-208). Comparing measurements, photographs and three-dimensional, computed-tomography reconstructions of LB1 with data and diagnoses from the literature on LS, we critically evaluate numerous skull and postcranial traits that Hershkovitz et al. identified as being shared by LB1 and patients with LS. The statements regarding most of these traits are new to the clinical literature and lack quantitative support. LB1 and patients with LS differ markedly in the size and shape of the cranium; thickness and pneumatization of cranial bones; morphology of the face, mandible, teeth, and chin; form of the shoulder, wrist, and pelvis; and general body proportions including relative foot size. Claims that patients with LS are similar to LB1 in displaying protracted scapulae, short clavicles, low degrees of humeral torsion, flaring ilia, and curved tibiae are not supported by data or corroborating images. Some points of similarity (e.g., femoral neck-shaft angle, femoral bicondylar angle, and estimated stature) can be found in other hominins, and cannot be considered diagnostic. From our review and analysis, we conclude that LB1 did not suffer from LS.

Late Pleistocene-Holocene non-passerine avifauna of Liang Bua (Flores, Indonesia)

ABSTRACT Liang Bua, a limestone cave on the Indonesian island of Flores, has a depositional sequence that spans the last 95,000 years and includes well-preserved faunal remains. Birds are well represented throughout the stratigraphic sequence at Liang Bua. Here, we present the results of the first comprehensive study of avian remains retrieved from Sector XI, a 2 m by 2 m archaeological excavation along the east wall of the cave. A total of 579 specimens were identified as avian, with 244 belonging to at least 26 non-passerine taxa in 13 families. The late Pleistocene assemblage (23 taxa) includes the first recorded occurrence of vultures in Wallacea, as well as kingfishers, snipes, plovers, parrots, pigeons, and swiftlets. Together, these taxa suggest that during this time the surrounding environment was floristically diverse and included several habitat types. Two of these taxa, the giant marabou Leptoptilos robustus and the vulture Trigonoceps sp., are extinct. Eight taxa were identified in the Holocene assemblage, and five of these were also present in the late Pleistocene. Imperial pigeons Ducula sp. and the Island Collared Dove Streptopelia cf. bitorquata appear only in the Holocene assemblage. The differences in faunal composition between the late Pleistocene and Holocene assemblages may reflect a change in avifaunal composition due to climatic and environmental changes near the Pleistocene-Holocene transition, possibly amplified by impacts associated with the arrival of modern humans; however, the small Holocene sample prevents a firm conclusion about faunal turnover from being made.

Development and application of a comprehensive analytical workflow for the quantification of non-volatile low molecular weight lipids on archaeological stone tools

Source determination of use-related residues on prehistoric stone tools is especially challenging, due to issues related to preservation, contamination and the contribution of residues from multiple sources. To increase confidence in this process, an analytical workflow was developed to include: (1) a sampling strategy that retains spatial information of the recovered residues and enables monitoring of environmental contamination; and (2) a sensitive and selective gas chromatography-tandem mass spectrometry (GC-MS/MS) procedure to quantify non-volatile low molecular weight lipids on stone artefacts. This workflow was applied to 14 stone artefacts excavated from deposits at Liang Bua, a limestone cave on the Indonesian island of Flores. These artefacts range in age between ∼14 000 and 1000 years old, and were preliminarily classified as either potentially showing traces of use (n = 7) or not (n = 7) using low magnification microscopy. Residues were sampled by direct solvent extraction off the surface of the artefacts. The aliquots were spiked with internal standards and derivatised. The trimethylsilyl derivatives of 40 saturated fatty acids, sterols, di- and tri-terpenoids and their analogues were quantified using optimised multiple reaction monitoring (MRM) transitions. Six of the potentially used artefacts contained sterols, phytosterols and terpenoids, either individually or in combination, whereas none of these compounds was commonly found on the seven artefacts preliminarily classified as unused. This suggests that these six artefacts may have been used as implements to process resources, and provides scope for further investigation. This workflow can also be adapted for the analysis of other archaeological objects.

A reassessment of the early archaeological record at Leang Burung 2, a Late Pleistocene rock-shelter site on the Indonesian island of Sulawesi

This paper presents a reassessment of the archaeological record at Leang Burung 2, a key early human occupation site in the Late Pleistocene of Southeast Asia. Excavated originally by Ian Glover in 1975, this limestone rock-shelter in the Maros karsts of Sulawesi, Indonesia, has long held significance in our understanding of early human dispersals into ‘Wallacea’, the vast zone of oceanic islands between continental Asia and Australia. We present new stratigraphic information and dating evidence from Leang Burung 2 collected during the course of our excavations at this site in 2007 and 2011–13. Our findings suggest that the classic Late Pleistocene modern human occupation sequence identified previously at Leang Burung 2, and proposed to span around 31,000 to 19,000 conventional 14C years BP (~35–24 ka cal BP), may actually represent an amalgam of reworked archaeological materials. Sources for cultural materials of mixed ages comprise breccias from the rear wall of the rock-shelter–remnants of older, eroded deposits dated to 35–23 ka cal BP–and cultural remains of early Holocene antiquity. Below the upper levels affected by the mass loss of Late Pleistocene deposits, our deep-trench excavations uncovered evidence for an earlier hominin presence at the site. These findings include fossils of now-extinct proboscideans and other ‘megafauna’ in stratified context, as well as a cobble-based stone artifact technology comparable to that produced by late Middle Pleistocene hominins elsewhere on Sulawesi.

Early human symbolic behavior in the Late Pleistocene of Wallacea

Significance We present evidence from the Late Pleistocene of Sulawesi, Indonesia, where an unusually rich and unique symbolic complex was excavated from archaeological deposits spanning 30,000 to 22,000 y ago. Including previously unknown practices of self-ornamentation, used ochre, pigmented artifacts, and portable art, these findings advance our knowledge of the cultural repertoires of modern humans in Pleistocene Wallacea, including the nonparietal artworks and symbolic material culture of some of the world’s earliest known “cave artists.” Wallacea, the zone of oceanic islands separating the continental regions of Southeast Asia and Australia, has yielded sparse evidence for the symbolic culture of early modern humans. Here we report evidence for symbolic activity 30,000–22,000 y ago at Leang Bulu Bettue, a cave and rock-shelter site on the Wallacean island of Sulawesi. We describe hitherto undocumented practices of personal ornamentation and portable art, alongside evidence for pigment processing and use in deposits that are the same age as dated rock art in the surrounding karst region. Previously, assemblages of multiple and diverse types of Pleistocene “symbolic” artifacts were entirely unknown from this region. The Leang Bulu Bettue assemblage provides insight into the complexity and diversification of modern human culture during a key period in the global dispersal of our species. It also shows that early inhabitants of Sulawesi fashioned ornaments from body parts of endemic animals, suggesting modern humans integrated exotic faunas and other novel resources into their symbolic world as they colonized the biogeographically unique regions southeast of continental Eurasia.