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. Am J Phys Anthropol 156:148–157, 2015 © 2014 Wiley Periodicals, Inc.     

The calvaria of Sangiran 38, Sendangbusik, Sangiran Dome, Java

We describe in detail Sangiran 38 (S38), an adult partial calvaria recovered in 1980 from the Bapang (Kabuh) Formation of the Sangiran Dome near the hamlet of Sendangbusik, Java. Several other hominins (Bukuran, Hanoman 1, and Bs 9706) recovered in the vicinity come from either the upper-most Sangiran (Pucangan) or lower-most Bapang formations. S38 is from the lower Bapang Formation, which ⁴⁰Ar/³⁹Ar age estimates suggest spans between 1.47 and 1.58 Ma. Anatomical and metric comparisons with a worldwide set of ‘early non-erectus’ Homo, and Homo erectus (sensu lato) fossils indicate S38 is best considered a member of H. erectus. Although smaller in size, S38 is similar in overall morphology to the Bukuran specimen of similar age and provenance. The S38 calvaria exhibits several depressed lesions of the vault consistent with a scalp or systemic infection or soft tissue cyst.     

Brief communication: two human fossil deciduous molars from the Sangiran dome (Java, Indonesia): outer and inner morphology

Currently, the human deciduous dental record from the Pleistocene deposits of the Sangiran Dome, Java, consists of only eight specimens. Here we report two deciduous crowns collected near the village of Pucung. While their precise geo-chronological context remains unknown, a provenance from the Early-Middle Pleistocene Kabuh Formation, or from the Early Pleistocene "Grenzbank Zone," is very likely. These isolated specimens consist of an upper first molar (PCG.1) and a lower second molar (PCG.2). Taxonomic discrimination of the Indonesian tooth record is difficult because of the convergence in crown size and appearance between Pongo and Homo. Accordingly, as PCG.2 still bears a concretion masking most of its features, we coupled the outer analysis of the two specimens with an investigation of their inner morphology. In addition to external characteristics, virtual imaging and quantitative assessment of inner morphology and tissue proportions support an attribution to the taxon Homo, and we preliminary allocate both specimens toH. erectus.     

Three newHomo erectus mandibles from Java

There are now eleven manidublar pieces from the Lower and Middle Pleistocene of Java, all but one being from the Sangiran site. All of these have been assigned toHomo erectus by most workers, while others have suggested as many as four different hominoid taxa. Sangiran 21 (Mandible E), Sangiran 22 (Mandible F), and Sangiran 37 (Mandible G) are described here fully for the first time. Sangiran 21, 22, and 27 all come from the Upper Pucangan Formation and date approximately 1.2 Myr. The new mandibles are morphologically compatible with theH. erectus, crania from Java.     

New 1.5 million-year-old Homo erectus maxilla from Sangiran (Central Java, Indonesia)

Sangiran (Solo Basin, Central Java, Indonesia) is the singular Homo erectus fossil locale for Early Pleistocene Southeast Asia. Sangiran is the source for more than 80 specimens in deposits with ⁴⁰Ar/³⁹Ar ages of 1.51-0.9 Ma. In April 2001, we recovered a H. erectus left maxilla fragment (preserving P³- M²) from the Sangiran site of Bapang. The find spot lies at the base of the Bapang Formation type section in cemented gravelly sands traditionally called the Grenzbank Zone. Two meters above the find spot, pumice hornblende has produced an ⁴⁰Ar/³⁹Ar age of 1.51 ± 0.08 Ma. With the addition of Bpg 2001.04, Sangiran now has five H. erectus maxillae. We compare the new maxilla with homologs representing Sangiran H. erectus, Zhoukoudian H. erectus, Western H. erectus (pooled African and Georgian specimens), and Homo habilis. Greatest contrast is with the Zhoukoudian maxillae, which appear to exhibit a derived pattern of premolar-molar relationships compared to Western and Sangiran H. erectus. The dental patterns suggest distinct demic origins for the earlier H. erectus populations represented at Sangiran and the later population represented at Zhoukoudian. These two east Asian populations, separated by 5000 km and nearly 800 k.yr., may have had separate origins from different African/west Eurasian populations.     

Taxonomic affinities and evolutionary history of the Early Pleistocene hominids of Java: dentognathic evidence

Temporal changes, within-group variation, and phylogenetic positions of the Early Pleistocene Javanese hominids remain unclear. Recent debate focused on the age of the oldest Javanese hominids, but the argument so far includes little morphological basis for the fossils. To approach these questions, we analyzed a comprehensive dentognathic sample from Sangiran, which includes most of the existing hominid mandibles and teeth from the Early Pleistocene of Java. The sample was divided into chronologically younger and older groups. We examined morphological differences between these chronological groups, and investigated their affinities with other hominid groups from Africa and Eurasia. The results indicated that 1) there are remarkable morphological differences between the chronologically younger and older groups of Java, 2) the chronologically younger group is morphologically advanced, showing a similar degree of dentognathic reduction to that of Middle Pleistocene Chinese H. erectus, and 3) the chronologically older group exhibits some features that are equally primitive as or more primitive than early H. erectus of Africa. These findings suggest that the evolutionary history of early Javanese H. erectus was more dynamic than previously thought. Coupled with recent discoveries of the earliest form of H. erectus from Dmanisi, Georgia, the primitive aspects of the oldest Javanese hominid remains suggest that hominid groups prior to the grade of ca. 1.8-1.5 Ma African early H. erectus dispersed into eastern Eurasia during the earlier Early Pleistocene, although the age of the Javanese hominids themselves is yet to be resolved. Subsequent periods of the Early Pleistocene witnessed remarkable changes in the Javanese hominid record, which are ascribed either to significant in situ evolution or replacement of populations.     

Two new“Meganthropus” mandibles from Java

There are now eleven known mandibular pieces from the Lower and Middle Pleistocene of Java, all but one being from the Sangiran site. All of these have been assigned toHomo erectus by most authorities, while others have suggested as many as four different hominoid taxa. Two of the mandibles, Sangiran 33 (Mandible H) and“Meganthropus”D (no Sangiran number yet assigned), are described here for the first time. The two new mandibles come from the Upper Pucangan Formation and date approximately 1.2–1.4 Myr. They are morphologically compatible with other“Meganthropus” mandibles described from Java. Despite attempts by numerous authorities to place all the Sangiran hominid mandibles in the species,H. erectus, the range of variation in metric and nonmetric features of the“Meganthropus” hominids is clearly beyond the know variation found inH. erectus. “Meganthropus” could represent a speciation from the well-knownH. erectus.     

Frontal bone fragment of<Emphasis Type="Italic">Homo erectus</Emphasis> from Sangiran,Java

In 1994 a hominid frontal bone fragment was found in the river floor of the Brangkal River, the Sangiran area, Central Java. The original stratigraphic level is not known at present stage of the research. But it is possible that the bone was derived from the Grenzbank zone of the Bapang Formation (Lower/Middle Pleistocene). Morphological features of the bone, such as a thick and continuous supraorbital torus, a wide and flat supratoral plane, and a flat and strongly inclined frontal squame suggest that the bone is assigned to JavaneseHomo erectus, especially to the Sangiran and Trinil group of it.     

Sangiran 5,(“Pithecanthropus dubius”), homo erectus, “Meganthropus,” orPongo?

There are now eleven known mandibular remains from the Lower and Middle Pleistocene of Java, all but one being from the Sangiran site. All of these have been assigned toHomo erectus by most workers, while others have suggested as many as four different hominoid taxa. The author finds that the jaws cannot be a homogeneous sample. Morphologically, they are a mixture of undoubtedH. erectus, “H. meganthropus,” and possibly a pongid. If the jaws are allH. erectus then they have a sexual dimorphism exceeding that of modern gorillas. The case of“Pithecanthropus dubius” (Sangiran 5) is even less certain; even its hominid status is disputed. If it is indeedHomo it must be placed with the other“H. meganthropus” specimens. Its size and morphology are well beyond the known range anyH. erectus.     

Palaeoanthropological discoveries in Indonesia with special reference to the finds of the last two decades

This article reviews palaeoanthropological research in Indonesia since 1889 in terms of fossil discoveries. Of the three periods identified, the second one (1931–1941) resulted in more finds than the other two. Most finds are skull fragments of Pithecanthropus erectus, from the Middle Pleistocene Kabuh formation, and from the site of Sangiran. New code numbers are given to the finds to facilitate discussion, especially in the cases of previous misnumbering and controversial specimens.K/Ar dating gives an antiquity of 1·9 ± 0·4 million years for the Jetis beds at Perning (site of the Mojokerto juvenile calvaria) and 830,000 years for the Trinil beds at Sangiran (sites of Sangiran 10 and 12 calottes). Work on chronometric dating is continuing.Several re-examinations of earlier finds from Java have been performed in the last two decades. Finds during this period are reviewed and described, comprising one calvaria, two skull caps, two mandibular fragments, skull vault and base fragments, and teeth. One mandibular fragment is related to Meganthropus, but no skull fragments are associated with this to make its taxonomic status clearer. For the first time portion of the cranial base anterior to the foramen magnum and the zygomatic bone of Pithecanthropus erectus are available.The fossil finds demonstrate the genetic consistency of Pithecanthropus as revealed by the morphology of the skull. Palaeoanthropological research goes on, slowly but surely, especially in the Sangiran dome area of Central Java.     

A newHomo erectus cranium from Sangiran, Java

A newHomo erectus cranium was found on May 18, 1993 by Budi, a local farmer, at Sangiran. It dates from the Middle Pucangan Formation approximately 1.6–1.8 mya. The braincase is essentially complete and as is most of the face. The vault has the typicalH. erectus gable shape. There is a clear sagittal ridge beginning below the middle of the frontal squama and running to mid-parietal. Parasagittal ridges are rounded angulations halfway up the parietals, and coincide with poorly marked temporal lines. In all measurements, this skull is longer and consistently narrower than Trinil. It is chronologically and morphologically similar to the famousH. erectus skull from east Africa, KNMER-3733. Although existing much older, this new specimen is what one would expect a female counterpart to Sangiran 17 to look like.     

Homo erectus—who,when and where: A survey

The state of information bearing on Homo erectus as developed since about 1960 is surveyed, with the resulting effects on problems. Definitions of H. erectus still rest on the Far Eastern samples (Chou-k'ou-tien/Java), and thus relate to late Lower to middle Middle Pleistocene material. Numerous important individual finds, however, have expanded the total: extension of the early and very early Sangiran material; very early to later in Africa, and relatively late in Europe. Datings remain uncertain or controversial within broad limits, but with some important successes and revisions. Discussion by authors of problems concerns degree of divergence among H. erectus populations and rate of evolutionary change; both appear relatively slight, but the data are inadequate for much present judgment. The apparent zone of transition to more advanced morphology (H. sapiens, sensu lato) by the late Middle Pleistocene better reflects signs of regional divergence. Some writers—not all—believe that even the earliest European fossils known (e.g., Petralona) had already advanced to a H. sapiens basic level, with later change in the direction of Neanderthals. A separate African phylum, from OH 9, is also suggested; recent Chinese finds may provide a third different post-erectus population before the Upper Pleistocene. Taxonomic expression of all this gives some problems.     

A taxonomy of Javan hominid mandibles

The mandibular remains from Java have been controversial since the discovery of Kedung Brubus (Mandible A) in 1890. These mandibles, now called Kedung Brubus, and Sangiran 1, 5, 6, 8, 9, and 22, have been assigned to a wide variety of taxa. It is now commonly accepted that all seven mandibles can be accommodated in a single species;Homo erectus. A recent assessment to this effect was performed by Kramer (1989). Utilizing powerful statistical techniques he distinguished the Sangiran mandibles from the robust australopithecines and placed them all withinH. erectus. The jaws are not a homogeneous sample. Morphologically they are a mixture ofAustralopithecus africanus («Homo habilis») males (5,6), anA. africanus («H. habilis») female (8),H. erectus males (1,9), and aH. erectus female (22) and Kedung Brubus. The dating of these fossils remains unresolved, with a minimum date of 500,000 ya and a maximum of 1.6 mya. Any of the mandibles may have been transported and secondarily redeposited. If the jaws are allH. erectus then they have a sexual dimorphism exceeding that of modern gorillas. When Kedung Brubus is included with those from Sangiran the range of size dimorphism is well beyond that known for any primate, thus more than one species may be invloved. This dimorphism is found inA. africanus («H. habilis») but not inH. erectus samples anywhere else in the world. TheH. erectus skulls found in Java correspond with mandibles 1, 9, and 22. It is not likely that the largest mandible (6) is aH. erectus, because the skull would have had heavy temporal lines and probably a sagittal crest, neither of which is found on anyH. erectus specimen. But, a cranium has been found which morphologically matches the Sangiran 6 mandible. A double sagittal crest is present on Sangiran 31 a reported «Meganthropus» specimen.     

Modern human origins: continuity, replacement, and masticatory robusticity in Australasia

Morphological evidence for a Multiregional (MR) model of human origins is suggested by a series of “linking traits” seen in the crania of late Javanese Homo erectus from Ngandong and anatomically modern Australian crania. A few studies that consider the genetic, structural, or functional aspects of these regional traits suggest their appearance is heavily influenced not by shared phylogeny but by a common “strong” masticatory pattern. Using dental occlusal areas, external mandibular metrics, internal biomechanical properties of the mandibular corpus measured from CT scans, and nonmetric traits associated with the attachment of masticatory muscles, we test the hypothesis that Australians exhibit evidence of a “strong” masticatory pattern. We use a mixed-sex comparative human sample (n = 415) that includes precontact Alaskans from Point Hope and the Aleutian Islands, Californians, Peruvians, an urban forensic sample, and the late Pleistocene Afalou-Taforalt sample. In comparison with recent humans known to exhibit such patterns, Australian mandibles show none of the expected changes related to producing and dissipating heavy occlusal loads. This is true regardless of whether external or internal mandibular dimensions are considered, albeit Australians show large occlusal areas and relatively large section modulus indices. Thus, a prime functional argument proposed for the origin of some Australian regional features is not supported by these data.     

Hominid mandibular remains from Sangiran: 1952-1986 collection

Eight hominid mandibular and associated dental remains discovered between 1952-1986 from the Early Pleistocene deposits of Sangiran, Central Java, are described. Although the specimens are surface finds, their original stratigraphic positions can be reasonably inferred on the basis of coincidental sources of information. These specimens significantly increase the dento-gnathic sample available for intensive morphological investigation of the earliest Javanese hominids [Kaifu et al., 2005].     

Les assemblages fauniques associés aux sites à Homo erectus du dôme de Sangiran (Pléistocène moyen,Java, Indonésie)

In the Sangiran dome (Central Java), Homo erectus and mammal fossils in fluviatile context are found in several open-air localities: Tanjung, Sendang Busik, Ngrejeng Plupuh, Grogol Plupuh, and Bukuran. Thirteen taxa of Middle Pleistocene mammals were determined. Lithic tools are rare at these sites. The origin and setting up of these mainly unpublished faunal assemblages are approached by means of methods usually applied to European and African sites in order to understand better the link between humans and animals. The mechanical action of water is responsible for these accumulations and its chemical action for their evolution.     

A carnivorous niche for Java Man? A preliminary consideration of the abundance of fossils in Middle Pleistocene Java

Considering anatomical and archaeological aspects of Homo erectus, it is likely that meat of vertebrates was an important part in its diet. Unfortunately, no or hardly any information is available for Java Man (Homo erectus). Therefore, in this paper, the Number of Identified Specimens (NISP) of five Middle Pleistocene Javanese sites are examined, and the Minimum Number of Individuals (MNI) from two of them are calculated, to acquire information about the possible ecological role of Javanese Homo erectus. Although one has to be extremely careful with the interpretation of fossil bone assemblages in order to try to gain some insight about the abundance of species in palaeocommunities, it is argued that both the NISP and the MNI indicate that the bone accumulations reflect at least two trophic levels in the ecological pyramid, that of primary and secondary consumers. The occurrences of the remains of Homo erectus are comparable with the quantity of secondary consumers, i.e., large carnivores. This could suggest that this species had, as an omnivore, a carnivorous niche, in Java.