Late Pleistocene Humans Research Articles

The Undescribed Juvenile Maxilla from Contrebandiers Cave, Morocco—A Study on Middle Stone Age Facial Growth

In 2009, renewed excavations at the Middle Stone Age (MSA) site of Contrebandiers Cave, Morocco, yielded a skull and partial skeleton of a child dated to Marine Isotope Stage 5. While much of the cranium was found shattered, the midface remained largely intact. In this study, we virtually reconstructed the maxilla and quantified its shape using three-dimensional geometric morphometric methods and compared it to an extensive sample of non-adult and adult Eurasian Neanderthals and Homo sapiens spanning the Middle Pleistocene to Holocene. We used developmental simulations to predict the adult shape of the Contrebandiers maxilla by simulating development along three ontogenetic trajectories: Neanderthal, African, and Levantine early H. sapiens and Holocene H. sapiens. Our results confirm the H. sapiens-like morphology of the Contrebandiers fossil. Both shape and size align it with other North African MSA fossils and Late Pleistocene humans from Qafzeh, Israel. Interestingly, the evaluation of the ontogenetic trajectories suggests that during late ontogeny the facial growth pattern of the Contrebandiers and the Qafzeh children is more similar to that of Neanderthals than it is to recent humans. This suggests that the unique facial growth pattern of Homo sapiens post-dated the MSA. This study is an important step in addressing ontogenetic variability in the African MSA, a period characterized by the origins, emergence, and dispersal of our species, but poorly understood because of the fragmentary and scant human fossil record.

Trabecular bone volume fraction in Holocene and Late Pleistocene humans

Research suggests that recent modern humans have gracile skeletons in having low trabecular bone volume fraction (BV/TV) and that gracilization of the skeleton occurred in the last 10,000 years. This has been attributed to a reduction in physical activity in the Holocene. However, there has been no thorough sampling of BV/TV in Pleistocene humans due to limited access to high resolution images of fossil specimens. Therefore, our study investigates the gracilization of BV/TV in Late Pleistocene humans and recent (Holocene) modern humans to improve our understanding of the emergence of gracility. We used microcomputed tomography to measure BV/TV in the femora, humeri and metacarpals of a sample of Late Pleistocene humans from Dolní Věstonice (Czech Republic, ∼26 ka, n = 6) and Ohalo II (Israel, ∼19 ka, n = 1), and a sample of recent humans including farming groups (n = 39) and hunter-gatherers (n = 6). We predicted that 1) Late Pleistocene humans would exhibit greater femoral and humeral head BV/TV compared with recent humans and 2) among recent humans, metacarpal head BV/TV would be greater in hunter-gatherers compared with farmers. Late Pleistocene humans had higher BV/TV compared with recent humans in both the femur and humerus, supporting our first prediction, and consistent with previous findings that Late Pleistocene humans are robust as compared to recent humans. However, among recent humans, there was no significant difference in BV/TV in the metacarpals between the two subsistence groups. The results highlight the similarity in BV/TV in the hand of two human groups from different geographic locales and subsistence patterns and raise questions about assumptions of activity levels in archaeological populations and their relationships to trabecular BV/TV.

The relative limb size of Homonaledi

Homo erectus s.l. is key for deciphering the origin and subsequent evolution of genus Homo. However, the characterization of this species is hindered by the existence of multiple variants in both mainland and insular Asia, as a result of divergent chronogeographical evolutionary trends, genetic isolation, and interbreeding with other human species. Previous research has shown that cochlear morphology embeds taxonomic and phylogenetic information that may help infer the phylogenetic relationships among hominin species. Here we describe the cochlear morphology of two Indonesian H. erectus individuals (Sangiran 2 and 4), and compare it with a sample of australopiths, Middle to Late Pleistocene humans, and extant humans by means of linear measurements and both principal components and canonical variates analyses performed on shape ratios. Our results indicate that H. erectus displays a mosaic morphology that combines plesiomorphic (australopithlike) features (such as a chimplike round cochlear cross section and low cochlear thickness), with derived characters of later humans (a voluminous and long cochlea, possibly related to hearing abilities)—consistent with the more basal position of H. erectus. Our results also denote substantial variation between the two studied individuals, particularly in the length and radius of the first turn, as well as cross-sectional shape. Given the small size of the available sample, it is not possible to discern whether such differences merely reflect intraspecific variation among roughly coeval H. erectus individuals or whether they might result from greater age differences between them than currently considered. However, our results demonstrate that most characters found in later humans were already present in Indonesian H. erectus, with the exception of Neanderthals, which display an autapomorphic condition relative to other Homo species.

Cochlear morphology of Indonesian Homo erectus from Sangiran

Homo erectus s.l. is key for deciphering the origin and subsequent evolution of genus Homo. However, the characterization of this species is hindered by the existence of multiple variants in both mainland and insular Asia, as a result of divergent chronogeographical evolutionary trends, genetic isolation, and interbreeding with other human species. Previous research has shown that cochlear morphology embeds taxonomic and phylogenetic information that may help infer the phylogenetic relationships among hominin species. Here we describe the cochlear morphology of two Indonesian H. erectus individuals (Sangiran 2 and 4), and compare it with a sample of australopiths, Middle to Late Pleistocene humans, and extant humans by means of linear measurements and both principal components and canonical variates analyses performed on shape ratios. Our results indicate that H. erectus displays a mosaic morphology that combines plesiomorphic (australopithlike) features (such as a chimplike round cochlear cross section and low cochlear thickness), with derived characters of later humans (a voluminous and long cochlea, possibly related to hearing abilities)—consistent with the more basal position of H. erectus. Our results also denote substantial variation between the two studied individuals, particularly in the length and radius of the first turn, as well as cross-sectional shape. Given the small size of the available sample, it is not possible to discern whether such differences merely reflect intraspecific variation among roughly coeval H. erectus individuals or whether they might result from greater age differences between them than currently considered. However, our results demonstrate that most characters found in later humans were already present in Indonesian H. erectus, with the exception of Neanderthals, which display an autapomorphic condition relative to other Homo species.

Regional heterogeneity of environmental stressors for the Early, Middle and Late Palaeolithic European human populations related to the evolutionary lineage of Neanderthals

Pleistocene climatic fluctuations could play an important role in the development of the human phylogenetic line of Neanderthals. The aim of this study was to model how the climate-based physiological, cognitive, and vector-borne disease risk stressors for humans could vary in Europe by area and time from the Lower Palaeolithic era to the extinction of Neanderthals. For this purpose, the climatic requirements of the ancient humans were reconstructed based on the Early, Middle and Upper Palaeolithic occurrences of humans in Europe and its wider geographical environment for 8 Palaeolithic times and further six health and cold adaptation-related factors were also modelled. The adaptation of European human populations to the cool and volatile Pleistocene climate of Europe could gradually happen. While the Middle Palaeolithic humans in Europe lived in areas with long and medium-long vegetation periods and low or middle January mortality risk, in the late Palaeolithic the Neanderthal populations may have settled in areas with short ones. In January, these northern regions in the Late Palaeolithic era could be characterized by relatively high mortality risk. While the ancient humans of the Middle Palaeolithic era lived in such regions where the length of the thermal comfort season could be relatively long, the late Pleistocene humans of Europe occupied such regions where the thermal comfort season could be very short, and these humans should cover a large part of their body surface. However, the model results suggest that both humans of the Middle and Late Palaeolithic era should wear clothes in the coldest period of the winter in Europe. The Upper Palaeolithic populations could be less affected by such tick-borne diseases as Lyme borreliosis than the Early or the Middle Palaeolithic populations.

Possible vertebral brucellosis infection in a Neanderthal

The La Chapelle-aux-Saints 1 skeleton of an old (>60-year-old) male Neanderthal is renowned for the advanced osteoarthritis of its spinal column and hip joint, and their implications for posture and lifestyle in these Mid- to Late Pleistocene humans. Reassessment of the pathologic lesions reveals erosions at multiple non-contiguous vertebrae and reactive bone formation extending far beyond the left hip joint, which suggests the additional diagnosis of brucellosis. This implies the earliest secure evidence of this zoonotic disease in hominin evolution. Brucellosis might have been transmitted via butchering or eating raw meat and is well compatible with the range of prey animals documented for Neanderthals. The associated infertility could have represented an important aspect of health in these late archaic humans.

An early Holocene human skull from Zhaoguo cave, Southwestern China.

In this study, we describe a newly excavated early Holocene human cranium from Guizhou, Southwestern China, namely the Zhaoguo M1 (ZG 1). We aim to evaluate its morphological resemblance with Late Pleistocene human, and Northern and Southern China Neolithic populations. We also aim to infer its position in the process of East Asian population regionalization. The ZG 1 skull is almost complete, only missing parts of the right parietal and the basicranium around the foramen magnum. Comparative samples include Late Pleistocene humans and Neolithic populations from Northern and Southern China. Univariate and multivariate analyses are carried out in the study. ZG 1 has a dolichocephalic cranium, wide zygomatic breadth, moderate glabella and supraobtial projection, marked canine fossa, and thin cranial vault. The nasal floor, maximum cranial breadth position, and frontal arc proportion are all congruent with modern human. Statistical analysis suggests that ZG 1's measurements are most similar to those of Southern China Neolithic specimens, with some closer to Late Pleistocene humans. ZG 1 shows a clear affinity with Southern China Neolithic populations, providing further support that regionalization of morphological variability patterns between Northern and Southern Neolithic populations could have originated at least 10,000 years ago.

Dental Morphology of Naia, a Late Pleistocene Human from Mexico and the Sinodont/Sundadont Issue

ABSTRACT The dental morphology of the earliest Americans is poorly known, partly because existing data are largely unpublished and partly because dental wear is typically extreme in the few complete dentitions available. The remains of Naia, a 13,000–12,000 year-old young woman from Mexico's Yucatan Peninsula, possess a complete dental record in perfect condition, offering the unique opportunity to record the dental morphology of an early Paleoindian and a chance to address the long-standing debate about whether these first people exhibited Sundadont or Sinodont dental morphology. As an individual, her dentition would fit comfortably in the Sinodont grouping. However, when she is included in the population of North American skeletal remains that can be confidently placed before ∼9000 years ago, a different pattern emerges. The Paleoindians fall neatly between the two dental patterns, suggesting that the founding North American population exhibits a dental pattern of its own, independent of its east Asian relatives.

A demographic test of accidental versus intentional island colonization by Pleistocene humans

This study evaluates the hypothesis that some documented cases of long-distance sea crossing by the Late Pleistocene Homo sapiens occurred as a result of accidental drifting, rather than by intentional seafaring. For that purpose, we use an existing computer simulation framework, with some modifications, to investigate the likelihood that a planned or unplanned island colonization by a small group of individuals will persist to establish a viable population. Within the original framework, planned colonization was operationally characterized as being initiated by equal numbers of unrelated young men and women, whereas for unplanned colonization, those who migrate inadvertently were regarded in effect as a random sample of the whole population. Here, we consider a different scenario for unplanned colonization, which we believe is more relevant to sea crossing by the Late Pleistocene humans, that is, we assume that unplanned colonization occurs when members of households on watercrafts with limited voyaging capabilities are drifted away by ocean currents and washed up on a distant island. We also extend the previous analysis by considering a broader range of combinations of fertility and mortality schedules that individuals are assumed to follow. Our simulations suggest the following: (1) colonization of an island by ten or fewer unrelated young men and women can be successful within the feasible range of fertility and mortality levels; (2) in comparison, the likelihood of success for unplanned colonization is considerably smaller for the same range of fertility and mortality levels; and (3) there exists a small range of parameter combinations for which unplanned colonization has a non-negligible prospect of success even without assuming recurrent accidental drifts to the same island, and thus, the accidental colonization scenario cannot be totally excluded. In addition, we find that the minimum founding population required for successful colonization varies substantially depending on the fertility and mortality levels.

Snapshots of human anatomy, locomotion, and behavior from Late Pleistocene footprints at Engare Sero, Tanzania

Fossil hominin footprints preserve data on a remarkably short time scale compared to most other fossil evidence, offering snapshots of organisms in their immediate ecological and behavioral contexts. Here, we report on our excavations and analyses of more than 400 Late Pleistocene human footprints from Engare Sero, Tanzania. The site represents the largest assemblage of footprints currently known from the human fossil record in Africa. Speed estimates show that the trackways reflect both walking and running behaviors. Estimates of group composition suggest that these footprints were made by a mixed-sex and mixed-age group, but one that consisted of mostly adult females. One group of similarly-oriented trackways was attributed to 14 adult females who walked together at the same pace, with only two adult males and one juvenile accompanying them. In the context of modern ethnographic data, we suggest that these trackways may capture a unique snapshot of cooperative and sexually divided foraging behavior in Late Pleistocene humans.

Do Bayesian methods lead to more precise chronologies? ‘BayLum’ and a first OSL-based chronology for the Palaeolithic open-air site of Mirak (Iran)

Bayesian inference has been applied extensively to chronologies in archaeological science since it provides several advantages over the (classic) frequentist approach. One of the most important aspects of applying Bayesian methods is their capacity to consider the stratigraphic relationship between ages. In luminescence dating, a crucial motivation for applying Bayesian modelling is the ability to address the systematic shared uncertainty. The recently deployed R package ‘BayLum’ was developed to ameliorate luminescence-based chronologies by employing Bayesian modelling. Our contribution aims at estimating the impact of stratigraphic order and systematic shared uncertainty on the age results. In this paper, for the first time, we present a comprehensive luminescence-based chronology for the Middle- Upper Palaeolithic site of Mirak. This open-air site is located in the northern fringes of the Iranian central desert, which is considered to be one of the dispersal corridors for hominins (Neanderthal and modern human) living across western and central Asia. We compare chronologies derived by frequentist and Bayesian methods to discuss the effect of stratigraphic ordering and the correlation between samples due to systematic shared uncertainty. Our investigations indicate that applying the stratigraphic order, when age uncertainty overlap one another, plays a fundamental role in reducing the uncertainty. At the site Mirak the obtained Bayesian chronology considering the stratigraphic order for the layer containing predominately Upper Palaeolithic techno- complex results in 21–28 ka. The age of the intermediate layer is in the range of 26–33 ka, and the lower- most layer containing Middle Palaeolithic assemblage gives the age-range of 43–55 ka. These results indicate that Late Pleistocene humans have exploited the site during MIS 3–2. Furthermore, the chronology gives further evidence to the hypothesis that the Iranian central plateau served as a frequently used habitat and dispersal corridor for human groups populating western and central Asia.

External auditory exostoses among western Eurasian late Middle and Late Pleistocene humans.

External auditory exostoses (EAE) have been noted among the Neandertals and a few other Pleistocene humans, but until recently they have been discussed primary as minor pathological lesions with possible auditory consequences. An assessment of available western Eurasian late Middle and Late Pleistocene human temporal bones with sufficiently preserved auditory canals (n = 77) provides modest levels of EAE among late Middle Pleistocene archaic humans (≈20%) and early modern humans (Middle Paleolithic: ≈25%; Early/Mid Upper Paleolithic: 20.8%; Late Upper Paleolithic: 9.5%). The Neandertals, however, exhibit an exceptionally high level of EAE (56.5%; 47.8% if two anomalous cases are considered normal). The levels of EAE for the early modern humans are well within recent human ranges of variation, frequencies which are low for equatorial inland and high latitude samples but occasionally higher elsewhere. The Early/Mid Upper Paleolithic frequency is nonetheless high for a high latitude sample under interpleniglacial conditions. Given the strong etiological and environmental associations of EAE development with exposure to cold water and/or damp wind chill, the high frequency of EAE among the Neandertals implies frequent aquatic resource exploitation, more frequent than the archeological and stable isotopic evidence for Middle Paleolithic/Neandertal littoral and freshwater resource foraging implies. As such, the Neandertal data parallel a similar pattern evident in eastern Eurasian archaic humans. Yet, factors in addition to cold water/wind exposure may well have contributed to their high EAE frequencies.

Middle Stone Age humans in high-altitude Africa

Paleoanthropology Recent archaeological research has produced evidence of the earliest human occupation of high-altitude habitats in the Andes and the Tibetan Plateau. Ossendorf et al. now present the oldest evidence of human settlement and adaptation to areas above 4000-meter elevation in Africa (see the Perspective by Aldenderfer). Their excavations at a rock shelter in the Bale Mountains of Ethiopia reveal obsidian artifacts and faunal remains, including abundant burnt bones, mostly of giant mole-rats. The findings reveal the environmental conditions and show how Late Pleistocene humans adapted to the harsh environments of these glaciated high-altitude African landscapes. Science , this issue p. [583][1]; see also p. [541][2] [1]: /lookup/doi/10.1126/science.aaw8942 [2]: /lookup/doi/10.1126/science.aay2334

Middle Stone Age foragers resided in high elevations of the glaciated Bale Mountains, Ethiopia

Studies of early human settlement in alpine environments provide insights into human physiological, genetic, and cultural adaptation potentials. Although Late and even Middle Pleistocene human presence has been recently documented on the Tibetan Plateau, little is known regarding the nature and context of early persistent human settlement in high elevations. Here, we report the earliest evidence of a prehistoric high-altitude residential site. Located in Africa's largest alpine ecosystem, the repeated occupation of Fincha Habera rock shelter is dated to 47 to 31 thousand years ago. The available resources in cold and glaciated environments included the exploitation of an endemic rodent as a key food source, and this played a pivotal role in facilitating the occupation of this site by Late Pleistocene hunter-gatherers.

Ancient DNA from a 2,500-year-old Caribbean fossil places an extinct bird (Caracara creightoni) in a phylogenetic context

Since the late Pleistocene humans have caused the extinction of species across our planet. Placing these extinct species in the tree of life with genetic data is essential to understanding the ecological and evolutionary implications of these losses. While ancient DNA (aDNA) techniques have advanced rapidly in recent decades, aDNA from tropical species, especially birds, has been historically difficult to obtain, leaving a gap in our knowledge of the extinction processes that have influenced current distributions and biodiversity. Here we report the recovery of a nearly complete mitochondrial genome from a 2,500 year old (late Holocene) bone of an extinct species of bird, Caracara creightoni, recovered from the anoxic saltwater environment of a blue hole in the Bahamas. Our results suggest that this extinct species is sister (1.6% sequence divergence) to a clade containing the extant C. cheriway and C. plancus. Caracara creightoni shared a common ancestor with these extant species during the Pleistocene (1.2–0.4 MYA) and presumably survived on Cuba when the Bahamas was mostly underwater during Quaternary interglacial intervals (periods of high sea levels). Tropical blue holes have been collecting animals for thousands of years and will continue to improve our understanding of faunal extinctions and distributions. In particular, new aDNA techniques combined with radiocarbon dating from Holocene Bahamian fossils will allow us to place other extinct (species-level loss) and extirpated (population-level loss) vertebrate taxa in improved phylogenetic, evolutionary, biogeographic, and temporal contexts.

Mosaic dental morphology in a terminal Pleistocene hominin from Dushan Cave in southern China

Recent studies reveal high degrees of morphological diversity in Late Pleistocene humans from East Asia. This variability was interpreted as complex demographic patterns with several migrations and possible survival of archaic groups. However, lack of well-described, reliably classified and accurately dated sites has seriously limited understanding of human evolution in terminal Pleistocene. Here we report a 15,000 years-old H. sapiens (Dushan 1) in South China with unusual mosaic features, such as large dental dimensions, cingulum-like structures at the dentine level in the posterior dentition and expression of a “crown buccal vertical groove complex”, all of which are uncommon in modern humans and more typically found in Middle Pleistocene archaic humans. They could represent the late survival of one of the earliest modern humans to settle in an isolated region of southern China and, hence, the retention of primitive-like traits. They could also represent a particularity of this group and, hence, reflect a high degree of regional variation. Alternatively, these features may be the result of introgression from some late-surviving archaic population in the region. Our study demonstrates the extreme variability of terminal Pleistocene populations in China and the possibility of a complex demographic story in the region.

Recent research progress and popular issues on Chinese human evolution

Since human fossils were first discovered in Ordos, Inner Mongolia and Zhoukoudian, Beijing in the early 20th century, more than 70 Pleistocene human fossil sites have been found within China. Over the last decade, new human fossil findings in Tianyuan Cave, Chongzuo, Daoxian, Xuchang, among others and related research progress have directed the focus of international paleoanthropology communities to further investigate Chinese human origin and evolution. Some popular research issues include the emergence, evolution, and variation of Chinese Homo erectus and the existence of ancient humans prior to Homo erectus . The topics also extend to the emergence and dispersal of archaic and early modern Homo sapiens in China and the presence of gene communication between Chinese and European ancient humans. Based on the new discoveries of Chinese human fossils and respective research progress, several conclusions can be made. (1) Although some suspicious early human members or artifical stone tools have been found in areas in China, such as Longgupo, Fanchang, Jianshi, and Nihewan basin, these findings are not approved by the international community nor have they been proven to be actual human fossils. As of now, human fossils aging as early as 2.0 million years ago have yet to be discovered in China. As of now, human fossils aging as early as 2.0 million years ago have not yet to be discovered in China. (2) The earliest Homo erectus fossil unearthed from the stratum is the Lantian Gongwangling skull, which is about 1.15−1.63 million years old. (3) More than 10 Homo erectus fossils were found in China, such as Zhoukoudian, Hexian, Nanjing, and so on. During the evolutionary stage of Chinese Homo erectus , the most controversial issue is “whether they are a side–branch of human evolution.” The physical characteristics of Chinese Homo erectus are complex, and the internal variation is very big; thus, different Homo erectus branches or isolated populations probably existed in the late Middle Pleistocene of China. (4) Around 300−100 thousand years ago, some archaic Homo sapiens survived in China; they exhibit a morphological mosaic of East Asian and western contemporaries. During this period, it is probable that many types of ancient humans of genetic mixture existed in China. New human fossil evidences of two early Late Pleistocene crania from Lingjing, Xuchang provide a morphological mosaic relative to their western contemporaries. The two fossils exhibit similar pan-Old World trends in encephalization and in the supraorbital, neurocranial vault, and nuchal gracilization and reflect east Asian ancestry in a having low, sagitally flat and inferiorly broad neurocranium. They also display an occipital and temporal labyrinthine morphology similar to that of the Neandertals. This morphological combination reflects Pleistocene human evolutionary patterns in general biology, regional continuity, and interregional population dynamics. (5) Early modern human fossils have been found from several other sites in China, including Huanglong Cave, Zhiren Cave, and Daoxian. The findings indicate that early modern humans emerged about 100 ka BP in southern China, and fully modern morphology appeared 120−80 ka BP in some regions of southern China. At the same time, in northern China, human groups represented by Xujiayao still maintained primitive morphology and did not evolve into early moderns. Both early modern humans and fully modern humans probably first emerged in southern China, and then dispersed north. Available fossil evidence shows that Late Pleistocene humans in southern China exhibit pronounced variations, and several different evolutionary groups may exist. (6) Based on current human fossils and research progress, it is difficult or impossible to determine if early Chinese modern humans descended from Africa, local archaic humans, or were a crossbreed of the two.

Late Pleistocene humans in Sri Lanka used plant resources: A phytolith record from Fahien rock shelter

Little is known of the human use of rainforest plant resources of prehistoric Sri Lanka due to the lack of preservation of organic material and the effects of various destructive taphonomic processes. Phytoliths recovered from a AMS radiocarbon and OSL dated sequence at Fahien Rock Shelter indicate interactions of anatomically modern humans with the lowland rainforests of south-western Sri Lanka from 44,952–47,854 cal. BP to 11,991–12,402 cal. BP. During this period, the Rock Shelter occupants extracted their livelihood from a number of wild plants including bananas, rice, breadfruits, durians, canarium and species of palm and bamboo. These taxa are associated with present-day disturbed lowland rainforests. Gathering and processing of plant resources by existing modern rainforest foragers cannot directly be compared with the subsistence activities of the Late Pleistocene Rock Shelter occupants.

The well-behaved killer: Late Pleistocene humans in Eurasia were significantly associated with living megafauna only

The end of the Pleistocene was characterized by an intense, highly selective extinction event, affecting large-bodied terrestrial mammals worldwide. This period coincides with two major events, the last glacial period, and the dispersal of technologically advanced Homo sapiens outside the Old World. Upper Paleolithic hunters were armed with advanced, projectile weapons, and were able to dispatch prey as large as mammoths. As human population size was rapidly expanding, and hence means meat consumption rate was also growing, Paleolithic hunters are often held responsible for the extinction of mammalian megafauna. Yet, whether human focused on megafauna as prey, and drove them to extinction, remains uncertain. Here we model spatial and temporal patterns in habitat suitability for 24 megafauna species and Homo sapiens in Eurasia. We find that within land patches most suitable for humans, the identity of the most abundant herbivorous mammals switched from warm adapted species (such as the wild boar) to cold adapted species (reindeer) as climate switched from mild to cold conditions. Importantly, extinct herbivorous megafauna species were consistently rare within habitat patches optimal for humans. This suggests that humans may have settled under relatively constant climatic conditions, and possibly behaved as efficient predators, exploiting their prey in a cost-effective manner. These results are in accordance with evidence coming from the archaeological record, where medium sized living herbivore species are overrepresented in comparison of their natural abundance. For Late Pleistocene megafauna in Eurasia, human hunting may have been just an additional, non-decisive extinction factor.

A new look at an old dog: Bonn-Oberkassel reconsidered

The Bonn-Oberkassel dog remains (Upper Pleistocene and 14223 +- 58 years old) have been reported more than 100 years ago. Recent re-examination revealed the tooth of another older and smaller dog, making this domestic dog burial not only the oldest known, but also the only one with remains of two dogs. This observation brings the total known Magdalenian dogs to nine.Domestication of dogs during the final Palaeolithic has important implications for understanding pre-Holocene hunter-gatherers. Most proposed hunter-gatherer motivations for domesticating dogs have been utilitarian. However, remains of the Bonn-Oberkassel dogs may offer another view.The Bonn-Oberkassel dog was a late juvenile when it was buried at approximately age 27–28 weeks, with two adult humans and grave goods. Oral cavity lesions indicate a gravely ill dog that likely suffered a morbillivirus (canine distemper) infection. A dental line of suggestive enamel hypoplasia appears at the 19-week developmental stage. Two additional enamel hypoplasia lines, on the canine only, document further disease episodes at weeks 21 and 23. Pathological changes also include severe periodontal disease that may have been facilitated by immunodeficiency.Since canine distemper has a three-week disease course with very high mortality, the dog must have been perniciously ill during the three disease bouts and between ages 19 and 23 weeks. Survival without intensive human assistance would have been unlikely. Before and during this period, the dog cannot have held any utilitarian use to humans.We suggest that at least some Late Pleistocene humans regarded dogs not just materialistically, but may have developed emotional and caring bonds for their dogs, as reflected by the survival of this dog, quite possibly through human care.