Reconstructing the detailed dietary behaviour of extinct hominins is challenging1—particularly fo... more Reconstructing the detailed dietary behaviour of extinct hominins is challenging1—particularly for a species such as Australopithecus africanus, which has a highly variable dental morphology that suggests a broad diet2,3. The dietary responses of extinct hominins to seasonal fluctuations in food availability are poorly understood, and nursing behaviours even less so; most of the direct information currently available has been obtained from high-resolution traceelement geochemical analysis of Homo sapiens (both modern and fossil), Homo neanderthalensis4 and living apes5. Here we apply high-resolution trace-element analysis to two A. africanus specimens from Sterkfontein Member 4 (South Africa), dated to 2.6–2.1 million years ago. Elemental signals indicate that A. africanus infants predominantly consumed breast milk for the first year after birth. A cyclical elemental pattern observed following the nursing sequence—comparable to the seasonal dietary signal that is seen in contemporary wild primates and other mammals— indicates irregular food availability. These results are supported by isotopic evidence for a geographical range that was dominated by nutritionally depauperate areas. Cyclical accumulation of lithium in A. africanus teeth also corroborates the idea that their range was characterized by fluctuating resources, and that they possessed physiological adaptations to this instability. This study provides insights into the dietary cycles and ecological behaviours of A. africanus in response to food availability, including the potential cyclical resurgence of milk intake during times of nutritional challenge (as observed in modern wild orangutans5). The geochemical findings for these teeth reinforce the unique place of A. africanus in the fossil record, and indicate dietary stress in specimens that date to shortly before the extinction of Australopithecus in South Africa about two million years ago.
Radiocarbon dating of microgram residues is a relatively new field in archaeological science, so ... more Radiocarbon dating of microgram residues is a relatively new field in archaeological science, so far limited by analytical protocols and instrumentation. While successful applications using Accelerator Mass Spectrometry (AMS) have demonstrated the potential of the technique on such small samples, the analysis revealed challenges and problems, especially with contamination. Frequently, the presence of contaminants on the residue sample induces radiocarbon ages offset. Therefore, both residue identifications and contaminant removal protocols are keystone to achieve accurate dating. Along with this consideration, several other important steps in the sampling protocol sequence can influence the results and need to be carefully assessed. A constant improvement of sampling strategies and extracting methods to avoid contaminants compromising AMS dates is essential. Here we propose strategies for artefact handling (e.g. field work and archive) favorable for accurate AMS dating of stone tool...
A previous study by Yates et al. (2013) demonstrated the feasibility of AMS dating residues from ... more A previous study by Yates et al. (2013) demonstrated the feasibility of AMS dating residues from recently manufactured stone tools, on securely dated plant material by careful control of post-depositional contaminants including those possible during sample preparation. Since the results of that project demonstrated the applicability of AMS dating on residues, it seems plausible to now establish the possibility of applying the successful aspects of the methodology on artefacts from archaeological contexts. Therefore, the focus of the current study will be to conduct follow up research on European, Late Palaeolithic and Mesolithic stone tools, which originate from excavated and dated archaeological sites including a well-dated stratigraphy. We examine residues from stone tools of the German bog site Friesack 4, which comprises the most detailed stratigraphy from the Mesolithic in Europe known so far and from the Late Palaeolithic site in Wesseling (Germany) where the one phase occupat...
La phase 1 du site d'I Stantari (plateau de Cauria, Corse-du-Sud) datée du Néolithique Moyen ... more La phase 1 du site d'I Stantari (plateau de Cauria, Corse-du-Sud) datée du Néolithique Moyen comporte une centaine d'artefacts en obsidienne, matériau allochtone uniquement accessible au plus proche sur les îles-sources méditerranéennes de Lipari, Palmarola, Pantelleria et Sardaigne. Afin de reconstituer les schémas de consommation de cette roche, la totalité de l'assemblage a été analysée par LA-ICP-MS au sein du laboratoire SOLARIS (Southern Cross GeoScience, Southern Cross University, Australie). Les mesures obtenues pour une quinzaine d'éléments traces, suivant un protocole d'analyse nouvellement développé au sein de ce laboratoire, ont révélé que la matière première de cet assemblage lithique provenait exclusivement du massif volcanique sarde du Monte Arci. Ces données nous permettent de renforcer nos connaissances sur le phénomène obsidienne en Corse pour cette période, pour laquelle nous ne disposons pour l'instant que de peu de sites précisément étudiés.
Working with a large temporal dataset spanning several decades often represents a challenging tas... more Working with a large temporal dataset spanning several decades often represents a challenging task, especially when the record is heterogeneous and incomplete. The use of statistical laws could potentially overcome these problems. Here we apply Benford's Law (also called the "First-Digit Law") to the traveled distances of tropical cyclones since 1842. The record of tropical cyclones has been extensively impacted by improvements in detection capabilities over the past decades. We have found that, while the first-digit distribution for the entire record follows Benford's Law prediction, specific changes such as satellite detection have had serious impacts on the dataset. The least-square misfit measure is used as a proxy to observe temporal variations, allowing us to assess data quality and homogeneity over the entire record, and at the same time over specific periods. Such information is crucial when running climatic models and Benford's Law could potentially be...
ABSTRACT Electron spin resonance (ESR) has been used for absolute dating of archaeological materi... more ABSTRACT Electron spin resonance (ESR) has been used for absolute dating of archaeological materials such as quartz, flints, carbonate crystals, and fossil remains for nearly 50 years. The technique is based on the fact that certain crystal behaves as natural dosimeters. This means that electrons and holes are accumulated over time in the crystal lattice induced by surrounding radiation. The age is obtained by calculating the dose received compared to the dose rate generated by the surrounding environment, mainly radioisotopes K, U, and Th. The dating range is dependent on the nature and state of conservation of the sample and the surrounding environment but is between a few thousands and a couple of million years. Since, ESR dating is best and most commonly applied to tooth enamel in archaeology, this paper predominantly focuses on its direct application to fossil remains.
L'obsidienne était une matière première précieuse de l'industrie lithique néolithique. En... more L'obsidienne était une matière première précieuse de l'industrie lithique néolithique. En Méditerranée occidentale, elle se trouve parfois dans les sites archéologiques très éloignés des quatre "îles-sources" de Lipari, Palmarola, Pantelleria et Sardaigne. Si entre ces sources l'analyse visuelle ne permet d'attribuer qu'entre 70 et 85% des artefacts d'un site à un gisement potentiel, il est en revanche presque toujours possible d'identifier l'origine de ce matériau à partir de sa composition chimique. Comme il est nécessaire de traiter un nombre important d'objets archéologiques, la construction d'une stratégie analytique adaptée est aujourd'hui indispensable. Celle-ci combine l'approche visuelle aux caractérisations instrumentales par MEB-EDS, EDXRF, pXRF, PIXE et LA-ICP-MS. Des analyses exhaustives, réalisées sur plus de 9500 pièces (France continentale, Corse, Italie du Nord, Sardaigne, Tunisie), intégrées aux études typo-...
Reconstructing the detailed dietary behaviour of extinct hominins is challenging1—particularly fo... more Reconstructing the detailed dietary behaviour of extinct hominins is challenging1—particularly for a species such as Australopithecus africanus, which has a highly variable dental morphology that suggests a broad diet2,3. The dietary responses of extinct hominins to seasonal fluctuations in food availability are poorly understood, and nursing behaviours even less so; most of the direct information currently available has been obtained from high-resolution traceelement geochemical analysis of Homo sapiens (both modern and fossil), Homo neanderthalensis4 and living apes5. Here we apply high-resolution trace-element analysis to two A. africanus specimens from Sterkfontein Member 4 (South Africa), dated to 2.6–2.1 million years ago. Elemental signals indicate that A. africanus infants predominantly consumed breast milk for the first year after birth. A cyclical elemental pattern observed following the nursing sequence—comparable to the seasonal dietary signal that is seen in contemporary wild primates and other mammals— indicates irregular food availability. These results are supported by isotopic evidence for a geographical range that was dominated by nutritionally depauperate areas. Cyclical accumulation of lithium in A. africanus teeth also corroborates the idea that their range was characterized by fluctuating resources, and that they possessed physiological adaptations to this instability. This study provides insights into the dietary cycles and ecological behaviours of A. africanus in response to food availability, including the potential cyclical resurgence of milk intake during times of nutritional challenge (as observed in modern wild orangutans5). The geochemical findings for these teeth reinforce the unique place of A. africanus in the fossil record, and indicate dietary stress in specimens that date to shortly before the extinction of Australopithecus in South Africa about two million years ago.
Radiocarbon dating of microgram residues is a relatively new field in archaeological science, so ... more Radiocarbon dating of microgram residues is a relatively new field in archaeological science, so far limited by analytical protocols and instrumentation. While successful applications using Accelerator Mass Spectrometry (AMS) have demonstrated the potential of the technique on such small samples, the analysis revealed challenges and problems, especially with contamination. Frequently, the presence of contaminants on the residue sample induces radiocarbon ages offset. Therefore, both residue identifications and contaminant removal protocols are keystone to achieve accurate dating. Along with this consideration, several other important steps in the sampling protocol sequence can influence the results and need to be carefully assessed. A constant improvement of sampling strategies and extracting methods to avoid contaminants compromising AMS dates is essential. Here we propose strategies for artefact handling (e.g. field work and archive) favorable for accurate AMS dating of stone tool...
A previous study by Yates et al. (2013) demonstrated the feasibility of AMS dating residues from ... more A previous study by Yates et al. (2013) demonstrated the feasibility of AMS dating residues from recently manufactured stone tools, on securely dated plant material by careful control of post-depositional contaminants including those possible during sample preparation. Since the results of that project demonstrated the applicability of AMS dating on residues, it seems plausible to now establish the possibility of applying the successful aspects of the methodology on artefacts from archaeological contexts. Therefore, the focus of the current study will be to conduct follow up research on European, Late Palaeolithic and Mesolithic stone tools, which originate from excavated and dated archaeological sites including a well-dated stratigraphy. We examine residues from stone tools of the German bog site Friesack 4, which comprises the most detailed stratigraphy from the Mesolithic in Europe known so far and from the Late Palaeolithic site in Wesseling (Germany) where the one phase occupat...
La phase 1 du site d'I Stantari (plateau de Cauria, Corse-du-Sud) datée du Néolithique Moyen ... more La phase 1 du site d'I Stantari (plateau de Cauria, Corse-du-Sud) datée du Néolithique Moyen comporte une centaine d'artefacts en obsidienne, matériau allochtone uniquement accessible au plus proche sur les îles-sources méditerranéennes de Lipari, Palmarola, Pantelleria et Sardaigne. Afin de reconstituer les schémas de consommation de cette roche, la totalité de l'assemblage a été analysée par LA-ICP-MS au sein du laboratoire SOLARIS (Southern Cross GeoScience, Southern Cross University, Australie). Les mesures obtenues pour une quinzaine d'éléments traces, suivant un protocole d'analyse nouvellement développé au sein de ce laboratoire, ont révélé que la matière première de cet assemblage lithique provenait exclusivement du massif volcanique sarde du Monte Arci. Ces données nous permettent de renforcer nos connaissances sur le phénomène obsidienne en Corse pour cette période, pour laquelle nous ne disposons pour l'instant que de peu de sites précisément étudiés.
Working with a large temporal dataset spanning several decades often represents a challenging tas... more Working with a large temporal dataset spanning several decades often represents a challenging task, especially when the record is heterogeneous and incomplete. The use of statistical laws could potentially overcome these problems. Here we apply Benford's Law (also called the "First-Digit Law") to the traveled distances of tropical cyclones since 1842. The record of tropical cyclones has been extensively impacted by improvements in detection capabilities over the past decades. We have found that, while the first-digit distribution for the entire record follows Benford's Law prediction, specific changes such as satellite detection have had serious impacts on the dataset. The least-square misfit measure is used as a proxy to observe temporal variations, allowing us to assess data quality and homogeneity over the entire record, and at the same time over specific periods. Such information is crucial when running climatic models and Benford's Law could potentially be...
ABSTRACT Electron spin resonance (ESR) has been used for absolute dating of archaeological materi... more ABSTRACT Electron spin resonance (ESR) has been used for absolute dating of archaeological materials such as quartz, flints, carbonate crystals, and fossil remains for nearly 50 years. The technique is based on the fact that certain crystal behaves as natural dosimeters. This means that electrons and holes are accumulated over time in the crystal lattice induced by surrounding radiation. The age is obtained by calculating the dose received compared to the dose rate generated by the surrounding environment, mainly radioisotopes K, U, and Th. The dating range is dependent on the nature and state of conservation of the sample and the surrounding environment but is between a few thousands and a couple of million years. Since, ESR dating is best and most commonly applied to tooth enamel in archaeology, this paper predominantly focuses on its direct application to fossil remains.
L'obsidienne était une matière première précieuse de l'industrie lithique néolithique. En... more L'obsidienne était une matière première précieuse de l'industrie lithique néolithique. En Méditerranée occidentale, elle se trouve parfois dans les sites archéologiques très éloignés des quatre "îles-sources" de Lipari, Palmarola, Pantelleria et Sardaigne. Si entre ces sources l'analyse visuelle ne permet d'attribuer qu'entre 70 et 85% des artefacts d'un site à un gisement potentiel, il est en revanche presque toujours possible d'identifier l'origine de ce matériau à partir de sa composition chimique. Comme il est nécessaire de traiter un nombre important d'objets archéologiques, la construction d'une stratégie analytique adaptée est aujourd'hui indispensable. Celle-ci combine l'approche visuelle aux caractérisations instrumentales par MEB-EDS, EDXRF, pXRF, PIXE et LA-ICP-MS. Des analyses exhaustives, réalisées sur plus de 9500 pièces (France continentale, Corse, Italie du Nord, Sardaigne, Tunisie), intégrées aux études typo-...
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africanus, which has a highly variable dental morphology that suggests a broad diet2,3. The dietary responses of extinct hominins
to seasonal fluctuations in food availability are poorly understood, and nursing behaviours even less so; most of the direct information
currently available has been obtained from high-resolution traceelement geochemical analysis of Homo sapiens (both modern
and fossil), Homo neanderthalensis4 and living apes5. Here we apply high-resolution trace-element analysis to two A. africanus
specimens from Sterkfontein Member 4 (South Africa), dated to 2.6–2.1 million years ago. Elemental signals indicate that
A. africanus infants predominantly consumed breast milk for the first year after birth. A cyclical elemental pattern observed following
the nursing sequence—comparable to the seasonal dietary signal that is seen in contemporary wild primates and other mammals—
indicates irregular food availability. These results are supported by isotopic evidence for a geographical range that was dominated
by nutritionally depauperate areas. Cyclical accumulation of lithium in A. africanus teeth also corroborates the idea that their
range was characterized by fluctuating resources, and that they possessed physiological adaptations to this instability. This study
provides insights into the dietary cycles and ecological behaviours of A. africanus in response to food availability, including the
potential cyclical resurgence of milk intake during times of nutritional challenge (as observed in modern wild orangutans5).
The geochemical findings for these teeth reinforce the unique place of A. africanus in the fossil record, and indicate dietary
stress in specimens that date to shortly before the extinction of Australopithecus in South Africa about two million years ago.
africanus, which has a highly variable dental morphology that suggests a broad diet2,3. The dietary responses of extinct hominins
to seasonal fluctuations in food availability are poorly understood, and nursing behaviours even less so; most of the direct information
currently available has been obtained from high-resolution traceelement geochemical analysis of Homo sapiens (both modern
and fossil), Homo neanderthalensis4 and living apes5. Here we apply high-resolution trace-element analysis to two A. africanus
specimens from Sterkfontein Member 4 (South Africa), dated to 2.6–2.1 million years ago. Elemental signals indicate that
A. africanus infants predominantly consumed breast milk for the first year after birth. A cyclical elemental pattern observed following
the nursing sequence—comparable to the seasonal dietary signal that is seen in contemporary wild primates and other mammals—
indicates irregular food availability. These results are supported by isotopic evidence for a geographical range that was dominated
by nutritionally depauperate areas. Cyclical accumulation of lithium in A. africanus teeth also corroborates the idea that their
range was characterized by fluctuating resources, and that they possessed physiological adaptations to this instability. This study
provides insights into the dietary cycles and ecological behaviours of A. africanus in response to food availability, including the
potential cyclical resurgence of milk intake during times of nutritional challenge (as observed in modern wild orangutans5).
The geochemical findings for these teeth reinforce the unique place of A. africanus in the fossil record, and indicate dietary
stress in specimens that date to shortly before the extinction of Australopithecus in South Africa about two million years ago.