The evolutionary significance of the Wajak skulls Paul Storm Storm, P. The evolutionary significance of the Wajak skulls. — Scripta Geol., 110: 1-247, figs. 1-30, tabs. 1-121, Leiden, September 1995. Paul Storm, c/o J. de Vos, Nationaal Natuurhistorisch Museum, Postbus 9517, 2300 RA Leiden, The Netherlands. Keywords: Wajak, Java, prehistory, (micro)evolution, human skull, cranial variation/adaptation, China, Southeast Asia, Papua New Guinea, Australia. Ever since their description by Dubois (1920, 1922) the Wajak skulls Java) have played an important role in the discussions on the evolution of modern humans in Australasia. Because of the robust mor- phology of the skull, Wajak Man was seen as a link between Pleistocene hominids from Java (Solo) and Recent Australian Aborigines. However, for a long time hardly any attention has been paid to the contents of the other boxes with human, faunal and cultural remains, as collected by Dubois around 1890. Because a satisfactory description of the Wajak fossils has so far been lacking and the archaeo- logical context of the Wajak site has so far been ignored, the evolutionary position of Wajak Man nec- essarily remained unclear. The present study suggests that the evolutionary significance of the Wajak skulls can no longer be seen in terms of a Late Pleistocene transitional form between the Middle Pleistocene Solo skulls and Recent Australian Aborigines, nor can they be seen as proof of a gracile link between Chinese and Australian populations. Rather, the significance of these skulls is that they give some insight into microevolutionary processes that have taken place on Java itself. The most likely interpretation is to consider the Wajak skulls as Mesolithic robust representatives of the present inhabitants of Java. According to the hypothesis presented at the end of this thesis there are two species within the genus Homo in Australasia: Homo erectus and Homo sapiens. Within Homo sapiens one can recognise in Austral- asia two main types: a Sunda type (Chinese and Javanese) with strong neotenic trends, and a Sahul type (Papuans and Australians) which is closer to a generalised Homo sapiens morphology. Wajak-1 (Java) and Liujiang (China) possibly represent the earliest clear examples of the Proto-Sunda type (proto meaning more robust). Hence, they are from this point of view, very important skulls when trying to understand the origin of the Sunda people. Gracilisation of the human skull, as has occurred since the Late Pleistocene, has been reported from different parts of the world. Various explanations have been proposed for their occurrence, like the development of agriculture and climatic changes. To explain the worldwide decrease in size of the human body one could seek for a phenomenon that also has a global character. I propose the idea that because of population increase, technological innovations and rising temperatures, since the Late Pleistocene, various aspects of human life changed (like relaxation of predation, decrease of home range and mobility and increasing symbiosis with other organisms), which enabled an overall decrease in body size. Contents Introduction 3 The Wajak remains 3 The Australian link 6 The Middle Pleistocene Solo link 10 Local continuity 11 Conclusion and aim of this thesis 11 Material and methods 12 2 Storm. The evolutionary significance of the Wajak skulls. Scripta Geol., 110 (1995) Introducvon 12 Prehistoric skulls 12 Recent skulls 14 Archaic characters 15 Measurements 16 Non-metrical characters 18 Instruments and working-up the data 20 Sources of errors 20 The late prehistory of Indonesia 21 Sites 21 Taphonomy 25 Faunas 27 Archaeology 29 Dating 33 Conclusion 33 The human material from Wajak 34 Introduction 34 The cranium of Wajak-1 34 The mandible of Wajak-1 44 The teeth of Wajak-1 44 The cranial bones of Wajak-2 45 The mandible of Wajak-2 49 The teeth of Wajak-2 53 Single teeth 54 Postcranial human skeletal material 54 Number of individuals 56 Sex of the Wajak skulls 57 Age of the Wajak skulls 58 Pathology of Wajak-1 58 Stature of Wajak man 59 Measuring the Wajak skulls 59 Wajak-1 and Wajak-2 61 Conclusion 61 The human material from Hoekgrot 62 Introduction 62 The red-painted skeleton 62 The non-coloured human remains 65 Number of individuals 69 Sex of the red-painted skeleton 69 Age of the red-painted skeleton 69 Age of the juvenile 69 Stature of the red-painted skeleton 70 Pathology of the red-painted skull 70 Conclusion 70 The Kanalda skull (Australia) 71 Introduction 71 Storm. The evolutionary significance of the Wajak skulls. Scripta Geolv 110 (1995) 3 State of preservation 71 Diagnosis of the sex 71 Estimation of the age 72 Conclusion 72 Cranial variation in Homo sapiens 72 Introduction 72 Measurements 73 Indices 76 Modules 78 Non-metrical characters 80 Sexual dimorphism 85 Recent Javanese and prehistoric Indonesian skulls 93 Recent and prehistoric skulls from China 99 Recent and prehistoric skulls from Australia 101 Recent crania from Papua New Guinea 106 Conclusion 107 A Solo-Wajak-Australian connection? 108 Introduction 108 The Solo connection 109 The Wajak-Australian connection 112 Conclusion 119 Adaptation of the craniofacial complex 120 Introduction 120 The shift from Wajak to the recent Javanese skull morphology 120 Dietary adaptations 122 Climatic adaptations 123 Worldwide gracilisation of the modern human skull 124 Conclusion 125 Evolution of hominids in Australasia 126 Introduction 126 The emergence of the genus Homo 126 Two morphological types of Homo sapiens 128 The evolution of Homo sapiens in Australasia 130 Conclusion 132 Concluding remarks 133 Acknowledgements 135 References 136 Tables 144 Introduction The Wajak remains On October 24, 1888, B.D. van Rietschoten discovered a fossilised human skull (Theunissen, 1989) close to Tjerme, near Tjampoer Darat (Fig. 1), in a mountain slope of the Gunung Lawa (Fig. 2). Later, C.Ph. Sluiter of the 'Koninklijke Natuurkundige 4 Storm. The evolutionary significance of the Wajak skulls. Scripta Geol., 110 (1995) Fig. 1. The surrounding of Wajak (= Tjampoer Darat). 1 = Hoekgrot; 2 = Wajak; 3 = Kecil (see Fig. 2). Storm. The evolutionary significance of the Wajak skulls. Scripta Geol., 110 (1995) 5 Vereniging' (Royal Society of Natural Sciences) received a letter from van Rietscho• ten dated October 31,1888, with a drawing of the situation (Fig. 3). At the meeting of the Royal Society of Natural Sciences of December 13, 1888, Sluiter read out this let• ter of van Rietschoten (1889). According to van Rietschoten the Wajak skull was found during a mining exploration for 'marble' (indicated nowadays as limestone), although when pulled out the skull broke, four molars were still in the jaw. As van Rietschoten observed superficially, a low frontal bone and strong protruding zygo• matic bones characterised the skull. Above the fossils there was about one metre of clay, and beneath a conglomerate of small 'marble' stones, united with a limestone like clay. It appeared to him as if it had been washed up and down by the sea. In this layer, that was so fixed that it was hard to loosen it with a crowbar, the bones were found. On December 21,1888 Sluiter (in litt.) wrote to Dubois, who was at that moment in Sumatra, that he had received the skull from van Rietschoten. Sluiter remarked that the skull was in a very sad state, broken in a number of pieces. With a small piece he had tried to remove the lime with hydrochloric acid, and it worked very well. Sluiter questioned, because of the condition of the bone and the situation of the site, if the skull could be seen as a fossil. Sluiter wrote that he would sent the com• plete collection to Dubois. At the meeting of the Royal Society of Natural Sciences of April 11, 1889, Sluiter read out the reaction of Dubois (1890a), in which he declared what Sluiter had written to him, viz. that the Wajak skull was in a very sad state. Dubois had worked a full week on the skull, with a chisel, glue and plaster, before he had the complete skull standing before him. Further, Dubois mentioned the presence of fragments of carpal bones and ribs, and a piece of a heel bone, a thigh bone and lower jaw. Dubois' first impression of Wajak Man was that it greatly deviated from the 'Malay type' and that it rather resembled the 'Papuan type'. Furthermore, Dubois remarked that it was better not to continue the excavation at the Wajak site by people who were no experts. Van Rietschoten said that, after the importance of his find appeared to him, he had instructed to stop the excavation. Dubois, who went from Sumatra to Java, started his excavation at the Wajak site on June 9, 1890. In his notes Dubois (1890c) remarked that the Wajak-1 skull was found in a rock-fissure filled with breccia. In this rock-fissure no more human remains were found, but bones of animals, presumable deer, were found. However, as early as after a few days, the work at the site had to be delayed because of heavy rains. At the end of September 1890 the work at the Wajak site was resumed. Soon, a second specimen (Wajak-2) was found in the hard matrix with, according to Dubois (1890b), undeniable the same Australian (or Papuan) peculiarities as the first skull. The next month, October 1890, remains of a human skeleton were collected from the matrix that filled the above mentioned small rock-fissure, which presumably belong to the Wajak- 2 skull. Furthermore, fragments of various mammals were found, and a map of the site was made by Dubois' assistant de Winter (Fig. 4). Dubois (1920a, 1922) described the exact position of the site: 'Tjampur Darat or Wadjak, the capital of the district of Wadjak, is a village (dessa), south-west of the town of Tulung Agung, and about in the meridian of the Wilis-summit On the slope of the part of the mountain that extends, almost rectilinearly, over a distance of 800 meters in W.S.W.