The age of the hominin fossils from Jebel Irhoud, Morocco, and the origins of the Middle Stone Age (original) (raw)
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New fossils from Jebel Irhoud, Morocco and the pan-African origin of Homo sapiens
Fossil evidence points to an African origin of Homo sapiens from a group called either H. heidelbergensis or H. rhodesiensis. However, the exact place and time of emergence of H. sapiens remain obscure because the fossil record is scarce and the chronological age of many key specimens remains uncertain. In particular, it is unclear whether the present day 'modern' morphology rapidly emerged approximately 200 thousand years ago (ka) among earlier representatives of H. sapiens 1 or evolved gradually over the last 400 thousand years 2. Here we report newly discovered human fossils from Jebel Irhoud, Morocco, and interpret the affinities of the hominins from this site with other archaic and recent human groups. We identified a mosaic of features including facial, mandibular and dental morphology that aligns the Jebel Irhoud material with early or recent anatomically modern humans and more primitive neurocranial and endocranial morphology. In combination with an age of 315 ± 34 thousand years (as determined by thermoluminescence dating) 3 , this evidence makes Jebel Irhoud the oldest and richest African Middle Stone Age hominin site that documents early stages of the H. sapiens clade in which key features of modern morphology were established. Furthermore, it shows that the evolutionary processes behind the emergence of H. sapiens involved the whole African continent.
The North African Middle Stone Age and its place in recent human evolution
Abstract The North African Middle Stone Age (NAMSA, ~300-24 thousand years ago, or ka) features what may be the oldest fossils of our species as well as extremely early examples of technological region- alization and ‘symbolic’ material culture (d’Errico et al., 2009; Scerri, 2013a; Richter et al., 2017). The geographic situation of North Africa and an increased understanding of the wet-dry climatic pulses of the Sahara Desert also show that North Africa played a strategic role in continental-scale evolutionary processes by modulating human dispersal and demographic structure (Drake et al., 2011; Blome et al., 2012). However, current understanding of the NAMSA remains patchy and subject to a bewildering array of industrial nomenclatures that mask underlying variability. These issues are compounded by a geographic research bias skewed toward non-desert regions. As a result, it has been difficult to test long-established narratives of behavioral and evolutionary change in North Africa and to resolve debates on their wider significance. In order to evaluate existing data and identify future research directions, this paper provides a critical overview of the component elements of the NAMSA and shows that the timing of many key behaviors has close parallels with others in sub-Saharan Africa and Southwest Asia.
The definition and chronometric position of the Middle Paleolithic technocomplex of the ‘‘Aterian’’ are heavily debated. While for some, the presence of tanged lithics is sufficient to warrant the attribution of an assemblage to the ‘‘Aterian,’’ for others there is more to the ‘‘Aterian,’’ which is, however, defined in different ways. Here, we present thermoluminescence (TL) dating results on the multiple layer site of Ifri n’Ammar (Morocco), with an alternating double sequence of assemblages previously described as ‘‘Mousterian’’ and ‘‘Aterian’’ based on the presence/absence of tanged lithics. All the Middle Paleolithic industries at Ifri n’Ammar are technologically and typologically relatively similar to each other, as well as to the European Mousterian, with the most significant difference being the presence of tanged lithic artifacts in some layers. We prefer to use the term ‘‘Middle Paleolithic of Aterian facies/aspect,’’ instead of assigning it the status of a distinct technocomplex which is used in a chronostratigraphical sense. TL data of 83.3 ± 5.6 ka (weighted; n = 10) on heated lithics is obtained for the uppermost Middle Paleolithic level (Upper OS), which contains tanged lithic tools, as well as personal ornaments, while the underlying layer (Lower OS), which lacks tanged pieces, dates to 130.0 ± 7.8 ka (n = 9). The latter age is also a minimum for its underlying layer, which again contains tanged items, and thus the first appearance of tanging is significantly older in comparison with chronometric data from other sites. The discrepancy between TL and radiocarbon dates from the same levels at Ifri n’Ammar brings into question the reliability of radiocarbon analysis at the limits of the method. Keywords Aterian Dating Ifri n’Ammar Maghreb Middle Paleolithic Middle Stone Age Mousterian Northwest Africa Thermoluminescence
Proceedings of the …, 2007
Recent developmental studies demonstrate that early fossil hominins possessed shorter growth periods than living humans, implying disparate life histories. Analyses of incremental features in teeth provide an accurate means of assessing the age at death of developing dentitions, facilitating direct comparisons with fossil and modern humans. It is currently unknown when and where the prolonged modern human developmental condition originated. Here, an application of x-ray synchrotron microtomography reveals that an early Homo sapiens juvenile from Morocco dated at 160,000 years before present displays an equivalent degree of tooth development to modern European children at the same age. Crown formation times in the juvenile's macrodont dentition are higher than modern human mean values, whereas root development is accelerated relative to modern humans but is less than living apes and some fossil hominins. The juvenile from Jebel Irhoud is currently the oldest-known member of Homo with a developmental pattern (degree of eruption, developmental stage, and crown formation time) that is more similar to modern H. sapiens than to earlier members of Homo. This study also underscores the continuing importance of North Africa for understanding the origins of human anatomical and behavioral modernity. Corresponding biological and cultural changes may have appeared relatively late in the course of human evolution. dental development ͉ human evolution ͉ human origins ͉ synchrotron microtomography ͉ tooth growth †
Journal of Human Evolution, 2013
Recent genetic studies based on the distribution of mtDNA of haplogroup U6 have led to subtly different theories regarding the arrival of modern human populations in North Africa. One proposes that groups of the proto-U6 lineage spread from the Near East to North Africa around 40e45 ka (thousands of years ago), followed by some degree of regional continuity. Another envisages a westward human migration from the Near East, followed by further demographic expansion at w22 ka centred on the Maghreb and associated with a microlithic bladelet culture known as the Iberomaurusian. In evaluating these theories, we report on the results of new work on the Middle (MSA) and Later Stone (LSA) Age deposits at Taforalt Cave in Morocco. We present 54 AMS radiocarbon dates on bone and charcoals from a sequence of late MSA and LSA occupation levels of the cave. Using Bayesian modelling we show that an MSA non-Levallois flake industry was present until w24.5 ka Cal BP (calibrated years before present), followed by a gap in occupation and the subsequent appearance of an LSA Iberomaurusian industry from at least 21,160 Cal BP. The new dating offers fresh light on theories of continuity versus replacement of populations as presented by the genetic evidence. We examine the implications of these data for interpreting the first appearance of the LSA in the Maghreb and providing comparisons with other dated early blade and bladelet industries in North Africa.
The Middle Stone Age in East Africa and modern human origins
The African Archaeological Review, 1993
East Africa, the region where Merrick Posnansky started his professional career, has long been accepted as the major centre for the study of the origins of hominids and their technological systems. Recently, human geneticists and some palaeoanthropologists have also proposed an Afi'ican origin for anatomically modern humans (Homo sapiens sapiens), although much of the proof cited is from non-African sources -mainly Europe and the Middle East. Fortunately these models have stimulated reassessment of the sub-Saharan Middle Stone Age (MSA), the archaeological phase between 200,000 and 30,000 years ago which represents the beginnings of regional variation in technology and cultural adaptation as well as the period in which modern humans appeared. Long ignored by East African archaeologists in favour of the earliest cultural record, or, at the other extreme, Neolithic and Iron Age research, the MSA is critical to the evaluation of models of the emergence of our own species. This paper reviews the current arguments concerning the origin and dispersal of modern humans, and the importance of the MSA for the resolution of the problem. It also describes the results from a I990 survey for MSA sites conducted in southwestern Tanzania within the framework of these current models.
Hominid Cave at Thomas Quarry I (Casablanca, Morocco): Recent findings and their context
Quaternary International, 2010
The Thomas Quarry I locality was made famous in 1969 with the discovery of a human half-mandible in a cave. In 1985, further investigations revealed the presence of a Lower Acheulean assemblage in lower units of the section. From 1988 onwards, modern controlled excavations took place within the framework of the Franco-Moroccan co-operative project “Casablanca”. Acheulean artefacts, a rich mammalian fauna and four hominid teeth have been excavated from the cave. The faunal set indicates an open woodland environment. Carcasses were processed by carnivores, but cut-marks are absent, which raises the question of any human role in the bone accumulations. Stone knapping was mainly oriented towards flake production and a few bifaces have been imported into the site. Laser ablation ICP-MS dating combining the ESR and U-series data for the modelling of the U-uptake has given an US/ESR age of 501+94−76 ka for a human premolar while new OSL measurements yielded an age of 420 ± 34 ka for sediments immediately above the dated tooth and 391 ± 32 ka below. Nevertheless, biostratigraphy and lithostratigraphy point towards a greater antiquity.
Archaeological sites in northern Africa provide a rich record of increasing importance for the origins of modern human behaviour and for understanding human dispersal out of Africa. However, the timing and nature of Palaeolithic human behaviour and dispersal across northwestern Africa (the Maghreb), and their relationship to local environmental conditions, remain poorly understood. The cave of Rhafas (northeast Morocco) provides valuable chronological information about cultural changes in the Maghreb during the Palaeolithic due to its long stratified archaeological sequence comprising Middle Stone Age (MSA), Later Stone Age (LSA) and Neolithic occupation layers. In this study, we apply optically stimulated luminescence (OSL) dating on sand-sized quartz grains to the cave deposits of Rha-fas, as well as to a recently excavated section on the terrace in front of the cave entrance. We hereby provide a revised chronostratigraphy for the archaeological sequence at the site. We combine these results with geological and sedimentological multi-proxy investigations to gain insights into site formation processes and the palaeoenvironmental record of the region. The older sedimentological units at Rhafas were deposited between 135 ka and 57 ka (MIS 6 –MIS 3) and are associated with the MSA technocomplex. Tanged pieces start to occur in the archaeological layers around 109 ka, which is consistent with previously published chronological data from the Maghreb. A well indurated duricrust indicates favourable climatic conditions for the pedogenic cementation by carbonates of sediment layers at the site after 57 ka. Overlying deposits attributed to the LSA technocomplex yield ages of ~21 ka and ~15 ka, corresponding to the last glacial period, and fall well within the previously established occupation phase in the Maghreb. The last occupation phase at Rhafas took place during the Neolithic and is dated to ~7.8 ka.
Earliest evidence of modern human life history in North African early Homo sapiens
Proceedings of the National Academy of Sciences, 2007
Recent developmental studies demonstrate that early fossil hominins possessed shorter growth periods than living humans, implying disparate life histories. Analyses of incremental features in teeth provide an accurate means of assessing the age at death of developing dentitions, facilitating direct comparisons with fossil and modern humans. It is currently unknown when and where the prolonged modern human developmental condition originated. Here, an application of x-ray synchrotron microtomography reveals that an early Homo sapiens juvenile from Morocco dated at 160,000 years before present displays an equivalent degree of tooth development to modern European children at the same age. Crown formation times in the juvenile's macrodont dentition are higher than modern human mean values, whereas root development is accelerated relative to modern humans but is less than living apes and some fossil hominins. The juvenile from Jebel Irhoud is currently the oldest-known member of Homo ...
A late Middle Pleistocene Middle Stone Age sequence identified at Wadi Lazalim in southern Tunisia
Scientific Reports https://www.nature.com/articles/s41598-022-07816-x, 2022
The late Middle Pleistocene, starting at around 300 ka, witnessed large-scale biological and cultural dynamics in hominin evolution across Africa including the onset of the Middle Stone Age that is closely associated with the evolution of our species-Homo sapiens. However, archaeological and geochronological data of its earliest appearance are scarce. Here we report on the late Middle Pleistocene sequence of Wadi Lazalim, in the Sahara of Southern Tunisia, which has yielded evidence for human occupations bracketed between ca. 300-130 ka. Wadi Lazalim contributes valuable information on the spread of early MSA technocomplexes across North Africa, that likely were an expression of large-scale diffusion processes. The emergence of the Middle Stone Age (MSA) in North Africa has been traditionally considered the result of H. sapiens dispersals triggered by late Middle Pleistocene ecosystem fragmentation from areas of endemism in East Africa, where early H. sapiens fossils dated to ca. 200 ka 1 have been found; Sangoan and Lupemban technocomplexes would have represented the archaeological signature for these first expansions 2. This framework has been questioned in light of African Multiregionalism concepts building upon a series of independent data 3 , including the dating of MSA assemblages associated to H. sapiens fossils to ca. 315 ka at Jebel Irhoud 4,5 , as well as attempts for a more regional interpretation of technological sequences and variation 6,7. Late Middle Pleistocene human biogeography of North Africa is directly linked to the Sahara, which has long been identified as a driver for biological diversification and population separation 8,9. However, while being recognized as a critical area for human evolution, our current understanding of the Saharan biogeographic role remains speculative because its archaeological, geochronological, and paleoanthropological data are too scarce and poorly distributed to resolve the relationships between its northern and southern regions at this critical time period. Here, we report results from investigations at Wadi Lazalim in southern Tunisia, at the northern edge of the Sahara. The area preserves an open-air sedimentary sequence of mostly late Middle Pleistocene age-dating from at least Marine Isotopic Stage (MIS) 8 to the transition from the MIS6 to MIS5 interglacial. The archaeological evidence from lithic assemblages in sub-primary deposition comprises well-recognizable technological elements for which infrared luminescence data provide some chronometric insight revealing fresh information on early MSA human occupation of the northern Sahara and contributing new elements for the discussion about the spread of MSA techno-complexes from sub-Saharan Africa into North Africa in the late Middle Pleistocene.