Sangiran Dome Research Articles

New Hominin calvaria discovery from Grenzbank Layer of Sangiran Dome (Java, Indonesia): The last archaic Homo erectus lived in Java

Sangiran Dome in Central Java, Indonesia, is the most significant hominin site in Island Southeast Asia. Up to now, there are more than a hundred of Homo erectus individuals recovered from the site, and the most recent finding is an unpublished posterior part of Bjg 1602 skullcap, discovered by a local people in 2016 from the surface of Kali (River) Bojong, out of stratigraphical context. But, based on the hard concretion well attached on the fossil, consists of coarse conglomeratic sand and pisoid-limestones – defined for the first time by G.H.R. von Koenigswald as the grenzbank layer – this skullcap is interpreted originally from this layer. Stratigraphically, the layer is situated between the black clay of Pucangan Formation of Lower Pleistocene and the fluvio-volcanic sands of Kabuh Formation of Middle Pleistocene. Thus, this layer was deposited on the Sangiran site some 0.9–0.8 ma, which is the minimal age of the skull respectively. This paper aims to identify the possibly position of the specimen and its context to the Homo erectus evolution in Java. The specimen was analysed by applying the morphological and metrical descriptions of the external characters. Then, a comparative study to other African (n=5), Asian (n=7), and Javan Homo erectus (n=23) was conducted by using univariate and bivariate statistical analysis, in order to place the specimen into evolutionary perspective. The result shows that Bjg 1602 skullcap is very closed in morphology and size to the robust Sangiran 4 skullcap (firstly known as Pithecanthropus robustus), which is one of the robust Homo erectus members from the Early Pleistocene between 1.6 to 1.2 ma. Thus, it could be concluded that the specimen of Bjg 1602 represents the last survival of robust Homo erectus in Java during the early of Middle Pleistocene, some 0.9 ma.

Towards an astronomical age model for the Lower to Middle Pleistocene hominin-bearing succession of the Sangiran Dome area on Java, Indonesia

Well-dated paleoanthropological sites are critical for studying hominin evolution and dispersal, especially when related to regional or global climate change. For the rich hominin fossil record of Africa, this has been facilitated by the development of high-resolution astronomically tuned age models. So far, such age models are lacking for the Pleistocene of SE Asia with its similarly rich fossil hominin record. This study aims to develop an astronomical age model for the classical Sangiran Dome area of central Java, using a semi-quantitative grain size record of the hominin-bearing Sangiran and Bapang Formations. Two initial age models were established based on two different sets of tie points and approaches (constant sedimentation rate and Bayesian age modelling). These models, which correspond to the paleoanthropological short and long chronologies for the arrival of Homo erectus on Java, were used to convert the grain size record into a time series for time series analysis. The preferred initial age model was then used as a starting point to correlate or tune the grain size record to the LR04 benthic δ18O isotope stack. This tuning was constrained by the sudden switch in grain size from obliquity to double obliquity related cycles; this switch can be linked to the onset of the Mid-Pleistocene Transition at ∼1.2 Ma marked by a similarly abrupt change in ice age history. Two slightly different astronomical age models are presented, while a one cycle hiatus at the base of the Grenzbank cannot be excluded. These age models are in better agreement with the short paleoanthropological chronology, arguing for a late arrival of H. erectus on Java. Finally, such astronomical age models, when finalized, will provide the accurate, precise, and high-resolution age control required to gain insight into the influence of both regional and global climate change on the Pleistocene paleoenvironment and potentially the hominin population of Java.

The early Pleistocene aquatic palaeoecology in Central Java, Indonesia as recorded in mollusc assemblages from the Puren and Sangiran layers of the Sangiran Dome

The early Pleistocene aquatic palaeoecology in Central Java, Indonesia as recorded in mollusc assemblages from the Puren and Sangiran layers of the Sangiran Dome

When X-Rays Do Not Work. Characterizing the Internal Structure of Fossil Hominid Dentognathic Remains Using High-Resolution Neutron Microtomographic Imaging

The internal structure of the bones and teeth of extinct primates holds a significant amount of valuable paleobiological information for assessing taxonomy, phylogenetic relationships, functional, dietary and ecological adaptive strategies, and reconstructing overall evolutionary history. Technologies based on X-ray microfocus (X-µCT) and synchrotron radiation (SR-µCT) microtomography are increasingly used to noninvasively and non-destructively investigate the endostructural properties of fossil mineralized tissues. However, depending on the taphonomic dynamics that affected the specimens following deposition, and on the nature of diagenetic processes, X-µCT and even SR-µCT may provide only faint or no contrast between the mineralized tissues, thus complicating or inhibiting the study of structural features. Using a diverse sample of dentognathic hominid specimens from continental Asia, East Africa and Indonesia, chronologically ranging from the Late Miocene to the Early-Middle Pleistocene, we present examples of the successful application of another imaging technology, neutron microtomography (n-µCT), for the extraction, 3D rendering and quantitative assessment of internal morphological detail. The specimens were scanned at the ANTARES Imaging facility (SR4a beamline) at the FRM II reactor of the Technical University of Munich, Germany, at energies ranging from 3 to 25 meV. The datasets were reconstructed with a voxel size from 20 to 27 µm, i.e., at resolutions directly comparable to the X-ray-based microtomographic records commonly used in paleobiological studies of fossil primate remains. Our analyses focused on a mandible, SNSB-BSPG 1939 X 4, representing the Late Miocene hominid Sivapithecus from the Siwaliks of Pakistan; the early Early Pleistocene (Gelasian) partial mandible HCRP-U18-501 from Malawi, among the earliest specimens attributed to the genus Homo; and an assemblage of hominid dentognathic specimens from the Early-Middle Pleistocene deposits of the Sangiran Dome, Indonesia. While X-ray-based imaging revealed from low to moderate internal contrasts for the specimen of Sivapithecus, or from extremely poor to virtually no contrast for the Pleistocene remains from East Africa and Indonesia, the application of n-µCT produced sufficient differences in contrast to distinguish between tooth tissues on the one hand, and between cortical and trabecular bone on the other, thus enabling reliable qualitative and quantitative assessments of their characteristics.

STUDY OF SHALLOW GROUNDWATER CHARACTERISTICS IN SANGIRAN DOME, KALIJAMBE DISTRICT

<p><em>The purpose of this study are knowing the shallow groundwater flow patterns and characteristics in the Sangiran Dome. This research uses descriptive qualitative method, carried out with survey methods that are analyzed with spatial approach. Unit analysis of this studied is the landform unit the result of a overlay between the Geological’s Map, Genesis’s Process, and Slope’s Map, the result is 15 landform units. Data analysis techniques is to determine the pattern of shallow groundwater flow using the three point problem method. Data analysis is to determine the characteristics of groundwater by using the parameters of power oh Hydrogen (pH), temperature, and Electrical Conductivity (DHL). The results of this study are the shallow groundwater flow patterns in the Sangiran Dome are concentrated in the Kalibeng Formation, the diffuse flow patterns are in the Pucangan Formation and irregular flow patterns are found in Kabuh Formation and Noropuro. The characteristics of shallow groundwater in the Sangiran Dome, based on pH. Neutral classification are found in the Notopuro Formation, the lower Pucangan Formation; base pH classification found in Kabuh Formation, upper Pucangan Formation, and Kalibeng Formation; acidic pH classification is found in the Notopuro Formation. The low DHL classification is found in Notopuro Formation, Kabuh Formation, and Pucangan Formation while the moderate DHL classification is in the Kalibeng Formation.</em></p>

A younger "earliest human migration" to Southeast Asia.

New dating suggests that hominids arrived at the Sangiran dome later than had been thought

The variability of frontal and occipital features of Homo erectus: a comparative analysis of unpublished fragmentary fossils from Sangiran, Indonesia

Since the first publication of Dubois in 1894, the diagnosis of Homo erectus is based on a list of morphological features established and updated after successive major discoveries made in the 20th century. While the existence and limits of the Homo erectus s.l is still debated, the homogeneity of the Indonesian Homo erectus, which covers a chronological period of ca. 1.5 million years, is also regularly questioned. Most of the studies addressing this question remain focused on the few most preserved specimens, even if a significant number of fragmentary specimens are available which could help to better appreciate the morphological variability of this species. In this present analysis, several unpublished fragmentary frontal (n=6) and occipital (n=9) bones recovered from the Pucangan and Kabuh layers in the Sangiran dome (Central Java) are described, analyzed and compared to the 3D models of contemporaneous (Trinil, Sangiran) and younger (Solo series) Indonesian H. erectus, specimens from Zhoukoudian Lower Cave in China, Dmanisi (Georgia), as well as East African hominins (East and West Turkana, Olduvai). The results help to precise the anatomical characteristics of these isolated human remains and increase our knowledge of Javanese Homo erectus morphological variability.

When did Cuon reach Java? – Reinvestigation of canid fossils from Homo erectus faunas

The presence of the genus Cuon during the Pleistocene of Java is attested by the endemic species C. sangiranensis and C. crassidens, sometimes classified as C. alpinus, a species that is also part of the Holocene fauna and has persisted until today. The current study revises the fossil canid material from the Sangiran Dome, previously assigned variously to C. sangiranensis, C. crassidens, C. alpinus, C. javanicus, and C. trinilensis. It aims to reinvestigate the arrival of Cuon in Java, in particular in relation to the late early Pleistocene endemic canid of Java: the Cuon-sized Xenocyontrinilensis, which had evolved in situ on Java from the large X. merriami, and which could be a potential competitor to early Cuon in case of contemporaneity. We found that a mandible fragment from Pandejan (holotype of C. crassidens) shows a morphology typical for C. alpinus. However, a maxilla and a mandible from the Bapang Formation at Sangiran, including the holotype of C. sangiranensis, is here assigned to the early dhole species C. priscus. Our results indicate that Cuon was already present in Java during the early middle Pleistocene and probably arrived as part of the immigration events during the Kedung Brubus faunal stage. Since X. trinilensis and Cuon are both hypercarnivorous medium-sized dogs, similar ecological niches are expected for both species. Thus, X. trinilensis probably was outcompeted and replaced by C. priscus. In turn, the latter species was replaced by the extant species, C. alpinus, during the Nangdong faunal stage, likely as part of the next immigration phase, which then disappeared during the tropical rainforest fauna of the Punung faunal stage and re-entered at the onset of the Holocene.

Disentangling isolated dental remains of Asian Pleistocene hominins and pongines.

Scholars have debated the taxonomic identity of isolated primate teeth from the Asian Pleistocene for over a century, which is complicated by morphological and metric convergence between orangutan (Pongo) and hominin (Homo) molariform teeth. Like Homo erectus, Pongo once showed considerable dental variation and a wide distribution throughout mainland and insular Asia. In order to clarify the utility of isolated dental remains to document the presence of hominins during Asian prehistory, we examined enamel thickness, enamel-dentine junction shape, and crown development in 33 molars from G. H. R. von Koenigswald's Chinese Apothecary collection (11 Sinanthropus officinalis [= Homo erectus], 21 “Hemanthropus peii,” and 1 “Hemanthropus peii” or Pongo) and 7 molars from Sangiran dome (either Homo erectus or Pongo). All fossil teeth were imaged with non-destructive conventional and/or synchrotron micro-computed tomography. These were compared to H. erectus teeth from Zhoukoudian, Sangiran and Trinil, and a large comparative sample of fossil Pongo, recent Pongo, and recent human teeth. We find that Homo and Pongo molars overlap substantially in relative enamel thickness; molar enamel-dentine junction shape is more distinctive, with Pongo showing relatively shorter dentine horns and wider crowns than Homo. Long-period line periodicity values are significantly greater in Pongo than in H. erectus, leading to longer crown formation times in the former. Most of the sample originally assigned to S. officinalis and H. erectus shows greater affinity to Pongo than to the hominin comparative sample. Moreover, enamel thickness, enamel-dentine junction shape, and a long-period line periodicity value in the “Hemanthropus peii” sample are indistinguishable from fossil Pongo. These results underscore the need for additional recovery and study of associated dentitions prior to erecting new taxa from isolated teeth.

Hominin occupation of the Chinese Loess Plateau since about 2.1 million years ago.

Considerable attention has been paid to dating the earliest appearance of hominins outside Africa. The earliest skeletal and artefactual evidence for the genus Homo in Asia currently comes from Dmanisi, Georgia, and is dated to approximately 1.77-1.85 million years ago (Ma)1. Two incisors that may belong to Homo erectus come from Yuanmou, south China, and are dated to 1.7Ma2; the next-oldest evidence is an H. erectus cranium from Lantian (Gongwangling)-which has recently been dated to 1.63Ma3-and the earliest hominin fossils from the Sangiran dome in Java, which are dated to about 1.5-1.6Ma4. Artefacts from Majuangou III5 and Shangshazui6 in the Nihewan basin, north China, have also been dated to 1.6-1.7Ma. Here we report an Early Pleistocene and largely continuous artefact sequence from Shangchen, which is a newly discovered Palaeolithic locality of the southern Chinese Loess Plateau, near Gongwangling in Lantian county. The site contains 17 artefact layers that extend from palaeosol S15-dated to approximately 1.26Ma-to loess L28, which we date to about 2.12Ma. This discovery implies that hominins left Africa earlier than indicated by the evidence from Dmanisi.

Assemblages with bifacial tools in Eurasia (second part). What is going on in the East? Data from India, Eastern Asia and Southeast Asia

This second paper is part of a wider review of lithic complexes with bifacial technology, and is devoted to the Asian sector, from India to the south-eastern mainland and the archipelagos and China. For India, sites such as Attirampakham, Isampur, Morgaon and Singi-Talav are described in detail. For China, sites in the Bose Basin, but also Liangshan, Longgangsi and Houfang are included in discussions of technological strategies that are found a long way from East African roots. For the Southeast, discoveries from Thailand and Cambodia are presented, as are some major Indonesian sites (for instance Nebung and the Sangiran dome).

Position of the posterior skullcap fragment from Sendang Klampok (Sangiran Dome, Java, Indonesia) among the Javanese Homo erectus record

Indonesia, and particularly Java island, has been the place of the longest occupation by Homo erectus' species. Since the first Homo erectus found by Eugene Dubois in 1891 in the Trinil site, the discoveries of human remains have been regular, allowing the gathering of the most important concentration of Homo erectus in the world spanning more than 1.7 million years. The new fossil specimen discovered near Sendang Klampok in the Sangiran Dome (Central Java, Indonesia), which represents the left infero-posterior part of a skullcap, supplements the more ancient sample from Sangiran dome. The metrical and morphological features observed on this specimen with in particular the length of the parietomastoid suture, the lower position of the temporal lines which relief is blunt and joining those of the mastoidal crest and lateral part of the transverse occipital torus constituting an extensive formation covering the junction of the temporal, parietal and occipital bones, the protruding mastoid process, external occipital crest well expressed and shape of cerebellar lobes are many characters closer to the Ngandong hominins, clearly different from those of Kabuh (Bapang) and Zhoukoudian Lower Cave specimens.

Avian remains from the Early/Middle Pleistocene of the So'a Basin, central Flores, Indonesia, and their palaeoenvironmental significance

The So'a Basin in central Flores contains the earliest known evidence for hominins on this remote Indonesian island, with stone tools from this region dating back at least 1.0Ma. At least 16 late Early to early Middle Pleistocene terrestrial fossil localities record evidence for highly insular endemic faunas and proxy evidence for hominins. The hominin presence in the So'a Basin raises many questions as to how, when, and from where hominins arrived on the island, and key issues regarding their adaptation to this insular environment remain poorly understood. Here, we provide palaeoenvironmental data based on avian remains recovered during recent, systematic excavations of late Early to early Middle Pleistocene deposits at Mata Menge and Bo'a Leza in the So'a Basin. At least six species of birds in five avian orders were recovered, forming the oldest bird remains recovered from Wallacea. Two species, a swan (Cygnus sp.) and an eagle owl (Bubo sp.), no longer occur on Flores. The avian assemblage from Mata Menge and Bo'a Leza described here is indicative of an open environment with a strong open, freshwater component and nearby grasslands, and with forests at a distance. In that, it differs from the Late Pleistocene limestone cave site of Liang Bua, the find locality of Homo floresiensis, and is more similar to the Early Pleistocene Homo erectus sites of the Sangiran Dome on Java. Although little is known regarding the identity of the So'a Basin toolmakers, the presence of an open, savannah-type environment in the late Early to early Middle Pleistocene of Flores may have facilitated their dispersal from the Asian shelf into Wallacea.

The early Pleistocene deciduous hominid molar FS-72 from the Sangiran Dome of Java, Indonesia: A taxonomic reappraisal based on its comparative endostructural characterization.

Among the ten fossil hominid deciduous teeth reported so far from the Pleistocene sediments of the Sangiran Dome of Java are two isolated lower second molars: specimens PCG.2 from the Kabuh Formation and FS-72 from the Pucangan Formation. While PCG.2 appears to be certainly attributable to Homo erectus, FS-72 is somewhat more problematic, even though it is commonly listed within the Indonesian H. erectus hypodigm. Largely because of its large size, it was originally attributed to Meganthropus paleojavanicus. Subsequent study highlighted a set of metric and nonmetric crown features also found in Australopith and African early Homo (notably H. habilis) homologues. An additional problem with the taxonomic assignment of isolated teeth from the Pleistocene of Java is the presence of Pongo in these same deposits. To assess the taxonomic affinity of FS-72, we investigated its inner structure (tissue proportions and enamel-dentine junction morphology) by using techniques of 2-3D virtual imaging coupled with geometric morphometric analyses. The results show that FS-72 has thinner enamel compared to fossil and recent humans and that its topographic repartition more closely follows the pongine pattern. It also exhibits a Pongo-like elongated morphology of the enamel-dentine junction, with proportionally lower and mesiodistally spaced dentine horns. Given the morphological and metric similarities between fossil orangutan and H. erectus molars, we tested the hypothesis that its internal morphology more closely resembles the patterns evinced by PCG.2 and modern humans than Pongo. Accordingly, we consider that FS-72 more likely represents a dm2 of Pongo rather than Homo.

Molar crown inner structural organization in Javanese Homo erectus.

This contribution investigates the inner organizational pattern (tooth tissue proportions and enamel-dentine junction morphology) of seven Homo erectus permanent molar crowns from the late Lower-early Middle Pleistocene Kabuh Formation of the Sangiran Dome (Central Java, Indonesia). The previous study of their external characteristics confirmed the degree of time-related structural reduction occurred in Javanese H. erectus, and also revealed a combination of nonmetric features which are rare in the Lower and early Middle Pleistocene dental record, but more frequently found in recent humans. In accordance with their outer occlusal morphology, the specimens exhibit a set of derived internal features, such as thick to hyperthick enamel, an incomplete expression of the crest patterns at the enamel-dentine junction (EDJ) level, a sharp EDJ topography. As a whole, these features differ from those expressed in some penecontemporaneous specimens/samples representing African H. erectus/ergaster and H. heidelbergensis, as well as in Neanderthals, but occur in recent human populations. Further research in virtual dental paleoanthropology to be developed at macroregional scale would clarify the polarity and intensity of the intermittent exchanges between continental and insular Southeast Asia around the Lower to Middle Pleistocene boundary, as well as should shed light on the still poorly understood longitudinal evolutionary dynamics across continental Asia.

Pedo-sedimentary dynamics of the Sangiran dome hominid bearing layers (Early to Middle Pleistocene, central Java, Indonesia): A palaeopedological approach for reconstructing ‘Pithecanthropus’ (Javanese Homo erectus) palaeoenvironment

Fossil soils and pedosediments displayed in Quaternary fossil-bearing formations are an important proxy to describe the evolution of climates and environments. Through a study of the palaeosols in the Sangiran dome, a rich hominid-bearing site of central Java (Indonesia), we characterized their record of terrestrialization through regional volcano–tectonic activity and describe palaeoenvironments colonized by hominids.The thick sedimentary formations of the Sangiran dome are known to reflect the geological evolution of Central Java from the beginning of the Quaternary until the Middle Pleistocene. Homo erectus fossils are found in the ca. 1.5 Ma Sangiran (or Pucangan) Formation up to the ca.0.8 Ma Bapang (or Kabuh) Formation.This study combines field surveying, a micromorphological approach, and palynological data. The characterization of successive pedoclimatic contexts and toposequences helps in reconstruction of the local palaeogeography and climates (mainly influenced by south-eastern Asia monsoon cycles) that predominated during periods of palaeosol development.The base of the Upper Sangiran member displays the earliest fully continental deposits, corresponding to the development of an open landscape with wide coastal marshes and mangroves, with a rain forest cover on the hinterland. Higher in the stratigraphic succession, environments reflect a contrasting seasonal climate with a long dry season alternating with periods of more humid palustrine conditions.A further tectonic uplift of the hill ranges bordering the Solo depression (in which the Sangiran dome is located) resulted in topographic changes and increasing palaeogeographic heterogeneity, and therefore of soilscapes. From the Upper Sangiran member to the Bapang lower member, erosion of soil cover caused the accumulation of pedosediments in topographic depressions. These pedosedimentary deposits as well as volcanic ash accumulations were sudden and sometimes bury palaeoreliefs (catena, gilgai). Recurrent aridity proxies occur in the palaeosols found in the Bapang formation (which yielded the most numerous hominid fossils), reflecting a long dry season and an open vegetation landscape.

Additional evidence for morpho-dimensional tooth crown variation in a New Indonesian H. erectus sample from the Sangiran Dome (Central Java).

This contribution reports fifteen human fossil dental remains found during the last two decades in the Sangiran Dome area, in Central Java, Indonesia. Among this sample, only one of the specimens had already been briefly described, with the other fourteen remaining unreported. Seven of the fifteen isolated teeth were found in a secured stratigraphic context in the late Lower-early Middle Pleistocene Kabuh Formation. The remaining elements were surface finds which, based on coincidental sources of information, were inferred as coming from the Kabuh Formation. Mainly constituted of permanent molars, but also including one upper incisor and one upper premolar, this dental sample brings additional evidence for a marked degree of size variation and time-related structural reduction in Javanese H. erectus. This is notably expressed by a significant decrease of the mesiodistal diameter, frequently associated to the reduction or even loss of the lower molar distal cusp (hypoconulid) and to a more square occlusal outline. In addition to the hypoconulid reduction or loss, this new sample also exhibits a low frequency of the occlusal Y-groove pattern, with a dominance of the X and, to a lesser extent, of the+patterns. This combination is rare in the Lower and early Middle Pleistocene paleoanthropological record, including in the early Javanese dental assemblage from the Sangiran Dome. On the other hand, similar dental features are found in Chinese H. erectus and in H. heidelbergensis. As a whole, this new record confirms the complex nature of the intermittent exchanges that occurred between continental and insular Southeast Asia through the Pleistocene.

Local ecological profile for Paranthropus robustus in South Africa using stable carbon isotopes from associated bovid teeth

The biomechanical characterization of lower limb long bones in the chrono-ecogeographically diverse species Homo erectus is a fundamental step for assessing evolutionary changes in locomotor mode and body shape that occurred within the genus Homo. However, the samples available for the Early and earlier Middle Pleistocene are small and widely scattered in time and space, thus limiting our understanding of the nature and polarity of morphological trends. Compared to the African fossil record, loading histories based on detailed biomechanical assessment of diaphyseal strength in Indonesian H. erectus lower limb long bones have not been assessed. By using a microtomographic record (μCT), we performed a quantitative analysis of the biomechanical properties and structural organization of Kresna 11, a late Early Pleistocene adult H. erectus femoral shaft from the Sangiran Dome, Central Java. Relative to the modern human condition, Kresna 11 shows the predominant mediolateral cortical thickening (hypertrophy) and the distal displacement of the minimum diaphyseal breadth characteristic of early Homo femora, associated nonetheless with relatively modest cortical thickness within the mid-proximal portion. Synthetic functional imaging of the shaft through the planar representation of its inner structure has revealed distal thickening of the medial cortex, a feature previously unreported in H. erectus. The increase in relative mediolateral bending strength observed in Kresna 11 supports the hypothesis that, rather than simply reflecting differences in patterns of locomotor loading, biomechanical properties of the femoral shaft in archaic Homo are strongly influenced by body shape, i.e., variations in pelvic breadth and femoral neck length.

Structural analysis of the Kresna 11 Homo erectus femoral shaft (Sangiran, Java)

The biomechanical characterization of lower limb long bones in the chrono-ecogeographically diverse species Homo erectus is a fundamental step for assessing evolutionary changes in locomotor mode and body shape that occurred within the genus Homo. However, the samples available for the Early and earlier Middle Pleistocene are small and widely scattered in time and space, thus limiting our understanding of the nature and polarity of morphological trends. Compared to the African fossil record, loading histories based on detailed biomechanical assessment of diaphyseal strength in Indonesian H. erectus lower limb long bones have not been assessed. By using a microtomographic record (μCT), we performed a quantitative analysis of the biomechanical properties and structural organization of Kresna 11, a late Early Pleistocene adult H. erectus femoral shaft from the Sangiran Dome, Central Java. Relative to the modern human condition, Kresna 11 shows the predominant mediolateral cortical thickening (hypertrophy) and the distal displacement of the minimum diaphyseal breadth characteristic of early Homo femora, associated nonetheless with relatively modest cortical thickness within the mid-proximal portion. Synthetic functional imaging of the shaft through the planar representation of its inner structure has revealed distal thickening of the medial cortex, a feature previously unreported in H. erectus. The increase in relative mediolateral bending strength observed in Kresna 11 supports the hypothesis that, rather than simply reflecting differences in patterns of locomotor loading, biomechanical properties of the femoral shaft in archaic Homo are strongly influenced by body shape, i.e., variations in pelvic breadth and femoral neck length.

Comparative morphological and morphometric description of the hominin calvaria from Bukuran (Sangiran, Central Java, Indonesia)

We describe the hominin skull (called here “Bukuran”) discovered in the lower Kabuh (or “Bapang”) series near Sendangbusik, from the Bukuran area in the Sangiran dome. The fossil, heavily mineralized, consists of the parieto-occipital and the left temporal, and the frontal bones. When combined, those two cranial parts represent a rather complete and well-preserved calvaria. Its stratigraphic position was established after the discovery. A detailed description is presented of the morphological and metric features of the Bukuran calvaria, and comparisons are made with Asian Homo erectus from Indonesia and China. The estimated cranial capacity of Bukuran, the general shape of its cranial vault, its ectocranial structures, and its morphological and metrical characters are in the range of Asian Homo erectus, and show clear affinities with other Indonesian members of the species. We discuss the evolutionary status of the Bukuran calvaria and its implication for hominin history on Java.