T. Djubiantono’s research while affiliated with PUSAT PENELITIAN KOPI DAN KAKAO INDONESIA and other places

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.

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.

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.

www.antiquity.ac.uk/projgall/ricaut329/

The thick fossiliferous volcano-sedimentary series of the Sangiran dome area (Kalibeng, Pucangan, Grenzbank, Kabuh and Notopuro) from central Java (Indonesia) were deposited throughout the Quaternary and represent a succession of coastal, marine and finally continental terrestrial environments. Palaeosoils from these series of Southeast Asia are good indicators of the successive landscapes in which early hominids lived and migrated during the Lower and early Middle Pleistocene. This palaeopedological study deals with seven localities distributed over an area of ca. 50 km2. Six palaeosoil orders (histosol, gleysol, vertisol, argillisol, protosol, oxisol) are characterised and include 19 pedotypes. We investigated the south-eastern and northwestern fossiliferous regions, which show very different sedimentary sequences. The characterisation of successive pedoclimatic contexts and toposequences enables us to reconstruct the local palaeogeography and informs about the climate (mainly influenced by south-eastern Asia monsoon cycles) that prevailed during the periods of palaeosoil development. The first fully terrestrial levels were identified at the base of the upper Pucangan unit, corresponding to the development of an open landscape on earlier sites of wide coastal swamps. Higher up in the series, environments are indicative of a contrasted seasonal climate with a long dry season, alternate with periods of more humid palustrine conditions. Recurrent aridity proxies are then found in the overlying Grenzbank and Kabuh series (both have yield the most abundant hominid fossils). Soils from these series reflect a long dry season and an open vegetation landscape, in agreement with stratigraphical and palynological observations.