Late Pleistocene Specimens Research Articles

The estimation and evolution of hominin body mass.

Body mass is a critical variable in many hominin evolutionary studies, with implications for reconstructing relative brain size, diet, locomotion, subsistence strategy, and social organization. We review methods that have been proposed for estimating body mass from true and trace fossils, consider their applicability in different contexts, and the appropriateness of different modern reference samples. Recently developed techniques based on a wider range of modern populations hold promise for providing more accurate estimates in earlier hominins, although uncertainties remain, particularly in non-Homo taxa. When these methods are applied to almost 300 Late Miocene through Late Pleistocene specimens, the resulting body mass estimates fall within a 25-60 kg range for early non-Homo taxa, increase in early Homo to about 50-90 kg, then remain constant until the Terminal Pleistocene, when they decline.

Ancient DNA Contradicts the Presence of Social Voles (Genus Microtus, Subgenus Sumeriomys) in the Late Pleistocene of Western Europe

Taxonomic decisions made by palaeontologists are often based on a few morphological features preserved in the fossil material. This practice may sometimes lead to the description of new species based on single specimens, which are, in fact, extreme or aberrant morphological variants of known taxa. Ancient DNA (aDNA) analysis of the Late Pleistocene specimens from the archaeological site Petits Guinards (Creuzier-la-Vieux, Allier, France), described as a new vole Microtus (Sumeriomys) bifrons, did not confirm the species distinctness of the studied population. The genetically examined specimens belonged to Stenocranius anglicus and/or Microtus arvalis, the dominant species at the site. Our findings show that it is risky to describe new fossil taxa on the basis of phenotypic outliers or morphologically aberrant, rare specimens that do not fall within the previously known population variability. We also highlight the importance of ancient DNA in resolving taxonomic and nomenclature problems and classifying fossil mammals of the Late Pleistocene age.

A new species of small Camelidae from the Late Pleistocene of Brazil

ABSTRACTCamelids have been known in South America since the late Pliocene, where they arrived from North America as part of the Great American Biotic Interchange (GABI). They became extinct in North America by the late Pleistocene, while surviving in the Southern Cone of South America and in high altitudes of the Andean region. Extinct South American camelids are generally included in the genera Palaeolama and Hemiauchenia, members of which are larger than modern species. We describe here a new, small species of the genus Hemiauchenia based on late Pleistocene specimens previously assigned to Lama guanicoe. This specimen lived in northeastern Brazil at 22 345–21 907 cal a bp, and had a diet composed mainly of C3 plants.

The Tien Shan vole (Microtus ilaeus; Rodentia: Cricetidae) as a new species in the Late Pleistocene of Europe.

Grey voles (subgenus Microtus) represent a complex of at least seven closely related and partly cryptic species. The range of these species extends from the Atlantic to the Altai Mountains, but most of them occur east of the Black Sea. Using ancient DNA analyses of the Late Pleistocene specimens, we identified a new mtDNA lineage of grey voles in Europe. Phylogenetic analysis of mitochondrial DNA cytochrome b sequences from 23 voles from three caves, namely, Emine–Bair–Khosar (Crimea, Ukraine), Cave 16 (Bulgaria), and Bacho Kiro (Bulgaria), showed that 14 specimens form a previously unrecognized lineage, sister to the Tien Shan vole. The average sequence divergence of this lineage and the extant Tien Shan vole was 4.8%, which is similar to the divergence of grey vole forms, which are considered distinct species or being on the verge of speciation; M. arvalis and M. obscurus or M. mystacinus and M. rossiaemeridionalis. We estimated the time to the most recent common ancestor of the grey voles to be 0.66 Ma, which is over twice the recent estimates, while the divergence of the extant Tien Shan vole and the new lineage to be 0.29 Ma. Our discovery suggests that grey voles may have been more diversified in the past and that their ranges may have differed substantially from current ones. It also underlines the utility of ancient DNA to decipher the evolutionary history of voles.

Dietary paleoecology of bison and horses on the mammoth steppe of eastern Beringia based on dental microwear and mesowear analyses

In contrast to the modern Arctic, high-latitude ecosystems of the Late Pleistocene supported a diverse range of large mammalian herbivores, including abundant bison (Bison priscus) and horses (Equus sp.). This ‘mammoth steppe’ biome has no extant analog and modern tundra vegetation is likely incapable of supporting such a high density of large mammals. Compared to modern Arctic ecosystems, higher diversity and biomass of Late Pleistocene large mammal populations may have been sustained by more nutritious forage and/or dietary niche partitioning. We used dental microwear texture analysis and dental mesowear analysis of bison and horses (Bison priscus, Equus sp.) to characterize diet and assess the degree to which dietary differences supported co-existence of these dominant and likely competing herbivores on the mammoth steppe. Additionally, we compared microwear and mesowear of Late Pleistocene specimens to modern Alaska bison (reintroduced Bison bison athabascae and introduced Bison bison bison) and published microwear and mesowear data for extant bovids and equids. Our results demonstrate that Late Pleistocene bison and horses had less abrasive diets than modern obligate grazers, suggesting that these “grazers” of the mammoth steppe likely incorporated more forbs in their diets than modern grazers. Furthermore, Late Pleistocene bison and horses ate foods with similar textures, indicating that dietary niche partitioning alone cannot explain their co-occurrence. However, taphonomic differences between bison and horse specimens indicate potential spatial or temporal niche partitioning during the Late Pleistocene.

Human manual distal phalanges from the Middle Stone Age deposits of Klasies River Main Site, Western Cape Province, South Africa

Two new distal manual phalanges from the Middle Stone Age deposits of Klasies River Main Site are described. One (SAM-AP 6387) likely derives from ray II or ray III, whereas the other (SAM-AP 6388) is from the thumb. Both derive from a late adolescent or fully adult individual. They were recovered by H. Deacon from the same stratigraphic unit (submember W or possibly submember R) of the Shell and Sand Member of Cave 1, which places them between 100 and 90 ka. Both are comparatively small elements, and the possibility that they came from the same hand cannot be discounted at this time. These bones add to the meager and all too fragmentary postcranial human fossil sample from the Late Pleistocene of South Africa. These two specimens provide some additional evidence pertaining to the morphological attributes of the distal phalanges of the Middle Stone Age inhabitants of South Africa. Together with the distal pollical phalanx from Die Kelders (SAM-AP 6402), they are relatively small in comparison with homologs from recent human samples as well as Late Pleistocene specimens from Eurasia. Given their small sizes, the distal pollical phalanges from Klasies and Die Kelders are not dissimilar to Holocene Khoesan homologs. As expected, the Klasies elements differ noticeably from Neandertal homologs, especially in the narrowness of their shafts and distal tuberosities.

Body mass estimation in hominins from humeral articular dimensions.

While many attempts have been made to estimate body mass in hominins from lower limb bone dimensions, the upper limb has received far less attention in this regard. Here we develop new body mass estimation equations based on humeral articular breadths in a large modern human sample and apply them to 95 Plio-Pleistocene specimens. Humeral head superoinferior and total distal articular mediolateral breadths were measured in a morphologically diverse sample of 611 modern human skeletons whose body masses were estimated from bi-iliac breadth and reconstructed stature. Reduced major axis regressions were used to compute body mass estimation equations. Consistency of the resulting estimates with those derived previously using lower limb bone equations was assessed in matched Plio-Pleistocene individuals or samples. In the modern reference sample, the new humeral body mass estimation equations exhibit only slightly lower precision compared to the previously derived lower limb bone equations. They give generally similar estimates for Pleistocene Homo, after accounting for the different shape of the humeral head articular surface in archaic Middle and Late Pleistocene Homo, except for distal humeral estimates for Late Pleistocene specimens, which average somewhat below lower limb estimates. Humeral equations give body mass estimates for australopiths that appear much too high, except for Australopithecus sediba. A chimpanzee-based distal humeral articular formula appears to work well for larger australopith specimens. The new formulae provide a more secure foundation for estimating hominin body mass from humeri than previously available equations.

Evolutionary history and palaeoecology of brown bear in North-East Siberia re-examined using ancient DNA and stable isotopes from skeletal remains

Over 60% of the modern distribution range of brown bears falls within Russia, yet palaeoecological data from the region remain scarce. Complete modern Russian brown bear mitogenomes are abundant in the published literature, yet examples of their ancient counterparts are absent. Similarly, there is only limited stable isotopic data of prehistoric brown bears from the region. We used ancient DNA and stable carbon (δ13C) and nitrogen (δ15N) isotopes retrieved from five Pleistocene Yakutian brown bears (one Middle Pleistocene and four Late Pleistocene), to elucidate the evolutionary history and palaeoecology of the species in the region. We were able to reconstruct the complete mitogenome of one of the Late Pleistocene specimens, but we were unable to assign it to any of the previously published brown bear mitogenome clades. A subsequent analysis of published mtDNA control region sequences, which included sequences of extinct clades from other geographic regions, assigned the ancient Yakutian bear to the extinct clade 3c; a clade previously identified from Late Quaternary specimens from Eastern Beringia and Northern Spain. Our analyses of stable isotopes showed relatively high δ15N values in the Pleistocene Yakutian brown bears, suggesting a more carnivorous diet than contemporary brown bears from Eastern Beringia.

Functional relationship between dental macrowear and diet in Late Pleistocene and recent modern human populations

AbstractMany aspects of diet and behaviour can be gleaned from dental wear, including environmental conditions, food‐fracture properties, food processing techniques, and cultural habits. Specifically, the angulation (flat vs. steep) of molar wear has been used as an indicator of food toughness and has also been implicated in the use of grinding stones and pottery in food processing. In this work, we focus on the sequential phases of the power stroke of mastication in a functional way, measuring the inclination of molar wear facets through the occlusal fingerprint analysis method. Specifically, we have calculated the angulation of wear facets in upper and lower molars of Palaeolithic humans, extant hunter‐gatherers, and proto‐farmers to discern differences between groups with different diets.Contrary to previous analyses, our study shows that the molars of Late Pleistocene specimens are characterized by significantly steeper angles than those of modern hunter‐gatherers.The flat molar wear found in the latter group could be related to the excessive mixture of exogenous materials accidentally introduced into their foods, as indicated by ethnographic evidence. On the contrary, the steep wear angles characterizing the Palaeolithic group are probably associated with the consumption of a less abrasive diet, which could be ultimately due to food preparation techniques that incorporated less dust and grit into their diets.

On some aspects of Neandertal zygomatic morphology

Neandertals are characterized by a series of well-documented facial characteristics, including midfacial prognathism, large nasal and orbital areas, and a marked supraorbital torus. We provide a comparative morphometric study of another part of this facial complex, the frontal process of the zygomatic. We find that European Neandertals have a distinctly columnar form of the frontal process not found in recent modern humans and most Pleistocene modern humans. Some purportedly modern specimens and specimens pre-dating Neandertals exhibit the same pattern as European Neandertals, while others exhibit the modern human pattern. The columnar form is likely a retention of the ancestral state in Neandertals and the other late Pleistocene specimens that exhibit it, but variation in the pattern seen in early modern humans reveals possible insights into late Pleistocene human evolution.

The earliest unequivocally modern humans in southern China.

The hominin record from southern Asia for the early Late Pleistocene epoch is scarce. Well-dated and well-preserved fossils older than ∼45,000 years that can be unequivocally attributed to Homo sapiens are lacking. Here we present evidence from the newly excavated Fuyan Cave in Daoxian (southern China). This site has provided 47 human teeth dated to more than 80,000 years old, and with an inferred maximum age of 120,000 years. The morphological and metric assessment of this sample supports its unequivocal assignment to H. sapiens. The Daoxian sample is more derived than any other anatomically modern humans, resembling middle-to-late Late Pleistocene specimens and even contemporary humans. Our study shows that fully modern morphologies were present in southern China 30,000-70,000 years earlier than in the Levant and Europe. Our data fill a chronological and geographical gap that is relevant for understanding when H. sapiens first appeared in southern Asia. The Daoxian teeth also support the hypothesis that during the same period, southern China was inhabited by more derived populations than central and northern China. This evidence is important for the study of dispersal routes of modern humans. Finally, our results are relevant to exploring the reasons for the relatively late entry of H. sapiens into Europe. Some studies have investigated how the competition with H. sapiens may have caused Neanderthals' extinction (see ref. 8 and references therein). Notably, although fully modern humans were already present in southern China at least as early as ∼80,000 years ago, there is no evidence that they entered Europe before ∼45,000 years ago. This could indicate that H. neanderthalensis was indeed an additional ecological barrier for modern humans, who could only enter Europe when the demise of Neanderthals had already started.

Ursus arctos L., 1758 from Bukovynka Cave (W Ukraine) in an overview on the fossil brown bears size variability based on cranial material

Brown bear Ursus arctos is a permanent member of European Middle and Late Pleistocene carnivore assemblages, which shows great body size fluctuation over time. To study this subject we carried out extensive comparison of 37 cranial metric features based on 2954 measurements coming from 263 specimens. In the statistical analyses we included a new complete brown bear calvarium which was found in Bukovynka Cave in Ukraine and dated to postglacial period. The cranial material was divided into male and female sets and classified according to geographic and stratigraphic affiliation of the samples. Analyses revealed clear decrease in many skull dimensions from the Middle Pleistocene specimens through the Late Pleistocene and postglacial to the Holocene skulls. The trend is probably related with general climatic changes during this period. However, Late Pleistocene specimens from Iberian Peninsula were significantly smaller from other Late Pleistocene European skulls or even a bit younger from the Late Glacial and postglacial period for some dimensions. The deviation from the global trend could result from their isolation from other European populations. These conclusions can be drawn both for male and female skulls. The decrease in body size showed that U. arctos is dynamically evolving species. Thus, the size does not seem to be a perfect criterion in determining the biochronological age of the brown bear findings although a general decreasing trend in size with time is clearly visible. The size of brown bear is under the influence of many factors such as great sexual dimorphism, individual and population variability as well as global and local climatic conditions.

Stable isotope composition of Late Pleistocene-Holocene Eobania vermiculata (Müller, 1774) (Pulmonata, Stylommatophora) shells from the Central Mediterranean basin: Data from Grotta d’Oriente (Favignana, Sicily)

This paper presents stable isotopic results (oxygen and carbon) from both modern and Late Pleistocene-Holocene shells of the land snail Eobania vermiculata (Müller, 1774) from Favignana Island (Sicily). It aims to contribute to the understanding of climate and vegetation history of this region during formation of Upper Palaeolithic, Mesolithic and Meso-Neolithic deposits of Grotta d’Oriente (ORT). Results from both an evaporative model (FBM) and an empirical regional isotopic model (i.e. linear relation between oxygen isotopic composition of shells (δ 18Os) and those of local precipitation (δ 18Op)) indicate that the δ 18Os values of modern specimens are mainly controlled by local temperature, relative humidity and δ 18Op at the time of snail activity. Data also suggest that the modern snails are nocturnally active almost all-year round in the study area. The carbon isotopic compositions of shells (δ 13Cs) of the same specimens indicate a diet prevalently (or exclusively) composed of C3 vegetation. The δ 18Os values of Late Pleistocene specimens suggest that climate conditions at ∼14.2 ka cal BP were similar to the present day, in agreement with additional δ 18Os records from southern Italy. By contrast, early-middle Holocene shells are notably 18O-depleted and suggest wetter conditions, possibly combined with a decrease in isotopic composition of precipitation source, compared to the present day. When compared with regional palaeoclimatic records a large-scale isotopic response to millennial-scale changes in atmospheric and hydrological conditions (e.g. enhanced rainfall) in the central-eastern Mediterranean is observed during the early-middle Holocene. The δ 13Cs of Late Pleistocene and Holocene specimens are consistently higher than those of modern ones. For the Late Pleistocene, this could be reasonably explained in terms of water-stressed vegetation. On the other hand, this seems to be less valid for Holocene counterparts when the climate was wetter. Probably δ 13Cs values result from the combination of distinct competing factors, involving atmospheric CO 2 concentration, seasonal water budget, vegetation type-cover and other carbon sources. Results reveal coherent relationships between regional δ 18Os and δ 13Cs, demonstrating that Late Pleistocene-Holocene land snail shell remains from archaeological sites may provide useful snapshots of past seasonal climate conditions.

The human chin revisited: what is it and who has it?

Although the presence of a “chin” has long been recognized as unique to Homo sapiens among mammals, both the ontogeny and the morphological details of this structure have been largely overlooked. Here we point out the essential features of symphyseal morphology in H. sapiens, which are present and well-defined in the fetus at least as early as the fifth gestational month. Differences among adults in expression of these structures, particularly in the prominence of the mental tuberosity, are developmental epiphenomena and serve to emphasize the importance of studying this region in juveniles whenever possible. A survey of various middle to late Pleistocene fossil hominids for which juveniles are known reveals that these features are present in some late Pleistocene specimens assigned to H. sapiens, but not in all of the presumed anatomically modern H. sapiens (i.e., Qafzeh 8, 9, and 11). The adult specimens from Skhūl, as well as the adult Qafzeh 7 specimen, are similarly distinctive in symphyseal morphology. Neanderthals are quite variable in their own right, and they as well as other middle to late Pleistocene fossils lack the symphyseal features of H. sapiens. Some of the latter are, however, seen in the Tighenif (Ternifine) mandibles.