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Secure environmental contexts are crucial for hominin interpretation and comparison. The discovery of a Denisovan individual and associated fauna at Tam Ngu Hao 2 (Cobra) Cave, Laos, dating back to 164–131 ka, allows for environmental comparisons between this (sub)tropical site and the Palearctic Denisovan sites of Denisova Cave (Russia) and Baishiya Karst Cave (China). Denisovans from northern latitudes foraged in a mix of forested and open landscapes, including tundra and steppe. Using stable isotope values from the Cobra Cave assemblage, we demonstrate that, despite the presence of nearby canopy forests, the Denisovan individual from Cobra Cave primarily consumed plants and/or animals from open forests and savannah. Using faunal evidence and proxy indicators of climates, results herein highlight a local expansion of rainforest at ~ 130 ka, raising questions about how Denisovans responded to this local climate change. Comparing the diet and habitat of the archaic hominin from Cobra Cave with those of early Homo sapiens from Tam Pà Ling Cave (46–43 ka), Laos, it appears that only our species was able to exploit rainforest resources. [ABSTRACT FROM AUTHOR]

The Pleistocene presence of the genus Homo in continental Southeast Asia is primarily evidenced by a sparse stone tool record and rare human remains. Here we report a Middle Pleistocene hominin specimen from Laos, with the discovery of a molar from the Tam Ngu Hao 2 (Cobra Cave) limestone cave in the Annamite Mountains. The age of the fossil-bearing breccia ranges between 164–131 kyr, based on the Bayesian modelling of luminescence dating of the sedimentary matrix from which it was recovered, U-series dating of an overlying flowstone, and U-series–ESR dating of associated faunal teeth. Analyses of the internal structure of the molar in tandem with palaeoproteomic analyses of the enamel indicate that the tooth derives from a young, likely female, Homo individual. The close morphological affinities with the Xiahe specimen from China indicate that they belong to the same taxon and that Tam Ngu Hao 2 most likely represents a Denisovan. Evidence for the presence of Homo during the Middle Pleistocene is limited in continental Southeast Asia. Here, the authors report a hominin molar from Tam Ngu Hao 2 (Cobra Cave), dated to 164–131 kyr. They use morphological and paleoproteomic analysis to show that it likely belonged to a female Denisovan. [ABSTRACT FROM AUTHOR]

The capability of Pleistocene hominins to successfully adapt to different types of tropical forested environments has long been debated. In order to investigate environmental changes in Southeast Asia during a critical period for the turnover of hominin species, we analysed palaeoenvironmental proxies from five late Middle to Late Pleistocene faunas. Human teeth discoveries have been reported at Duoi U'Oi, Vietnam (70–60 ka) and Nam Lot, Laos (86–72 ka). However, the use of palaeoproteomics allowed us to discard the latter, and, to date, no human remains older than ~ 70 ka are documented in the area. Our findings indicate that tropical rainforests were highly sensitive to climatic changes over that period, with significant fluctuations of the canopy forests. Locally, large-bodied faunas were resilient to these fluctuations until the cooling period of the Marine Isotope Stage 4 (MIS 4; 74–59 ka) that transformed the overall biotope. Then, under strong selective pressures, populations with new phenotypic characteristics emerged while some other species disappeared. We argue that this climate-driven shift offered new foraging opportunities for hominins in a novel rainforest environment and was most likely a key factor in the settlement and dispersal of our species during MIS 4 in SE Asia. [ABSTRACT FROM AUTHOR]

Stable carbon and nitrogen isotope ratios of collagen from bone and dentin have frequently been used for dietary reconstruction, but this method is limited by protein preservation. Isotopes of the trace element zinc (Zn) in bioapatite constitute a promising proxy to infer dietary information from extant and extinct vertebrates. The 66Zn/64Zn ratio (expressed as δ66Zn value) shows an enrichment of the heavy isotope in mammals along each trophic step. However, preservation of diet-related δ66Zn values in fossil teeth has not been assessed yet. Here, we analyzed enamel of fossil teeth from the Late Pleistocene (38.4-13.5 ka) mammalian assemblage of the Tam Hay Marklot (THM) cave in northeastern Laos, to reconstruct the food web and assess the preservation of original δ66Zn values. Distinct enamel δ66Zn values of the fossil taxa (δ66Zncarnivore < δ66Znomnivore < δ66Znherbivore) according to their expected feeding habits were observed, with a trophic carnivore-herbivore spacing of +0.60‰ and omnivores having intermediate values. Zn and trace element concentration profiles similar to those of modern teeth also indicate minimal impact of diagenesis on the enamel. While further work is needed to explore preservation for settings with different taphonomic conditions, the diet-related δ66Zn values in fossil enamel from THM cave suggest an excellent long-term preservation potential, even under tropical conditions that are well known to be adverse for collagen preservation. Zinc isotopes could thus provide a new tool to assess the diet of fossil hominins and associated fauna, as well as trophic relationships in past food webs. [ABSTRACT FROM AUTHOR]

Abstract: New fossil material was recovered at Tam Hang during the second fieldwork season conducted in 2007, by a Lao-French-American team. The Tam Hang site is located in northern Laos, in the Hua Pan province, about 260 km from Vientiane. The breccias of the Tam Hang South locality produced 404 new fossil specimens which complete the previous material recovered in 2003. The fossiliferous deposits are described geologically. In terms of palaeontology, the mammalian fauna is essentially composed of isolated teeth of middle- to large-sized mammals (Artiodactyla, Perissodactyla, Proboscidea, Carnivora, Rodentia, Primates). The overall fauna is compared to the six well-documented Middle to Late Pleistocene faunas from the Indochinese province (Yenchingkuo, Phnom Loang, Thum Wiman Nakin, Lang Trang, Duoi U’Oi, Ma U’Oi). On the basis of the faunal composition and evolutionary stages of the species, a biochronological framework at the transition between the Middle Pleistocene and the Late Pleistocene is proposed. [Copyright &y& Elsevier]

Abstract: Tam Hang, located in northeastern Laos, in the Hua Pan province, is a reference site not only for its numerous archaeological and human remains, but also for its two faunal assemblages, whose composition suggests different dating in the Pleistocene. Discovered in 1934 by Jacques Fromaget, a new excavation of the site has been undertaken in 2003. During this campaign, at Tam Hang south, 575 isolated teeth of mammals were extracted from a deep layer of calcareous breccia. This assemblage corresponds to that one described by Arambourg and Fromaget [C. Arambourg, J. Fromaget, Le gisement quaternaire de Tam Nang (Chaîne Annamitique septentrionale). Sa stratigraphie et ses faunes, C. R. Acad. Sci. Paris 203 (1938) 793–795.], as characterized by the presence of Ursus premalayanus, and the rarity of Pongo pygmaeus. Systematics and analysis of teeth show that this new assemblage is composed of archaic subspecies, characteristic of the Middle Pleistocene. The faunal composition suggests ecological conditions also found in other Pleistocene sites of the South-East-Asia mainland area. Finally, the analysis of the process of preservation and deposition enables a brief description of the taphonomy specific of karstic systems. [Copyright &y& Elsevier]

Tam Pà Ling, a cave site in northeastern Laos, has yielded the earliest skeletal evidence of Homo sapiens in mainland Southeast Asia. The reliance of Pleistocene humans in rainforest settings on plant or animal resources is still largely unstudied, mainly due to poor collagen preservation in fossils from tropical environments precluding stable nitrogen isotope analysis, the classical trophic level proxy. However, isotopic ratios of zinc (Zn) in bioapatite constitute a promising proxy to infer trophic and dietary information from fossil vertebrates, even under adverse tropical taphonomic conditions. Here, we analyzed the zinc isotope composition (66Zn/64Zn expressed as δ66Zn value) in the enamel of two teeth of the Late Pleistocene (63–46 ka) H. sapiens individual (TPL1) from Tam Pà Ling, as well as 76 mammal teeth from the same site and the nearby Nam Lot cave. The human individual exhibits relatively low enamel δ66Zn values (+0.24‰) consistent with an omnivorous diet, suggesting a dietary reliance on both plant and animal matter. These findings offer direct evidence of the broad utilization of resources from tropical rainforests by one of the earliest known anatomically modern humans in Southeast Asia. [ABSTRACT FROM AUTHOR]