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Contemporaneity of Australopithecus, Paranthropus, and early Homo erectus in South Africa
Abstract
Dating the Drimolen hominins
Fossil hominins from South Africa are enriching the story of early human evolution and dispersal. Herries et al. describe the geological context and dating of the hominin-bearing infilled cave, or palaeocave, at a site called Drimolen in South Africa (see the Perspective by Antón). They focus on the age and context of a recently discovered Homo erectus sensu lato fossil and a Paranthropus robustus fossil, which they dated to ∼2.04 million to 1.95 million years ago. This makes Drimolen one of the best-dated sites in South Africa and establishes these fossils as the oldest definitive specimens of their respective species ever discovered. The age confirms that species of Australopithecus, Paranthropus , and early Homo overlapped in the karst of South Africa ∼2 million years ago.
Science , this issue p. eaaw7293 ; see also p. 34
... data [18][19][20][21] . Alongside the biomolecular revolution in archaeology, there has been a subtle but no less important revolution in geoarchaeological science, with analytical instrumentation affording increasingly finely resolved analyses, providing an even higher level of confidence and shifting focus into the microrealm 22 . ...
... https://doi.org/10.1038/s41559-023-02215-5 data [18][19][20][21] . Alongside the biomolecular revolution in archaeology, there has been a subtle but no less important revolution in geoarchaeological science, with analytical instrumentation affording increasingly finely resolved analyses, providing an even higher level of confidence and shifting focus into the microrealm 22 . ...
... U-series/electron spin resonance ages on teeth further constrained the fossil-bearing breccias under the flowstone to 2.04-1.95 Ma, together establishing the age of the world's oldest known remains of Homo erectus 21 . In this way, all of the varying cave lithologies were dated to generate an internally consistent high-resolution age estimate (~90 thousand years of deposition). ...
Advanced geoscience techniques are essential to contextualize fossils, artefacts and other archaeologically important material accurately and effectively. Their appropriate use will increase confidence in new interpretations of the fossil and archaeological record, providing important information about the life and depositional history of these materials and so should form an integral component of all human evolutionary studies. Many of the most remarkable recent finds that have transformed the field of human evolution are small and scarce, ranging in size from teeth to strands of DNA, recovered from complex sedimentary environments. Nevertheless, if properly analysed, they hold immense potential to rewrite what we know about the evolution of our species and our closest hominin ancestors.
... the hominin-bearing palaeocave system of Drimolen is located within the Fossil hominid sites of south africa UNescO World heritage centre in the Gauteng Province of south africa, known locally as the cradle of humankind (coh; Keyser et al. 2000;herries et al. 2020). Discovered in 1992, the locality is approximately 5-6 km north-east of other well-known sites such as sterkfontein and swartkrans . ...
... erectus (herries et al. 2020). the P. robustus sample includes a number of partial crania and skulls including the most complete female (DNh 7) and male (DNh 155) specimens of the species (Keyser 2000;herries et al. 2020;Martin et al. 2021;Rak et al. 2021). the vast majority of hominin fossils, however, are isolated teeth Moggi-cecchi et al. 2010;leece et al. 2022). ...
... Deposits between this reversal and the base of the Jangi Buttress (−5.5 to −1.6 m) are thus dated to between ~2.04 and 1.95 Ma (herries et al. 2020). this includes the recently discovered DNh 155 and DNh 152 P. robustus crania that were recovered from in situ breccia deposits (herries et al. 2020;Martin et al. 2021; Figure 1). the DNh 7 cranium as well as many of the hominin teeth previously described by Moggi-cecchi et al. (2010) andleece et al. (2022) were excavated between 1992 and 2008 by andre Keyser's team and come from ex situ collapsed breccia deposits within the cea (see Figure 1). ...
Background
The Drimolen Palaeocave site is situated within the UNESCO Fossil Hominid Sites of South Africa World Heritage Area and has yielded numerous hominin fossils since its discovery in 1992. Most of these fossils are represented by isolated dental elements, which have been attributed to either of two distinct hominin genera, Paranthropus and Homo.
Aim
This paper provides morphological descriptions for a further 19 specimens that have been recovered from the ∼2.04–1.95 Ma Drimolen Main Quarry (DMQ) deposits since 2008. This paper also discusses the two primary hypotheses used to explain Paranthropus robustus variation: sexual dimorphism, and micro-evolution within a lineage.
Subjects and methods
These 19 fossils are represented by 47 dental elements and expand the sample of DMQ early Homo from 13 to 15, and the sample of Paranthropus robustus from 69 to 84.
Results
The evidence presented in this paper was found to be inconsistent with the sexual dimorphism hypothesis.
Conclusion
Some support was found for the micro-evolution hypothesis.
... We purposefully avoid discussion of the hominin species (or multiple species) that may have been the first to disperse into Eurasia. This is a period when multiple hominin species coexisted at sites in eastern and southern Africa 45,46 . The taxonomic affinity of nearly all hominin fossils in Fig. 5 is debated; many are identified only to Homo sp. and others are identified as Homo erectus/ergaster. ...
... The taxonomic affinity of nearly all hominin fossils in Fig. 5 is debated; many are identified only to Homo sp. and others are identified as Homo erectus/ergaster. Present evidence 46,47 indicates that the earliest H. erectus sensu lato was present in both South Africa and Ethiopia ca. 2.0 Ma; this therefore broaches the possibility that, if hominins were present in Eurasia prior to 2.0 Ma, then they may not have been H. erectus, and/or that H. erectus is older than we currently have data for. ...
The timing of the initial dispersal of hominins into Eurasia is unclear. Current evidence indicates hominins were present at Dmanisi, Georgia by 1.8 million years ago (Ma), but other ephemeral traces of hominins across Eurasia predate Dmanisi. However, no hominin remains have been definitively described from Europe until ~1.4 Ma. Here we present evidence of hominin activity at the site of Grăunceanu, Romania in the form of multiple cut-marked bones. Biostratigraphic and high-resolution U-Pb age estimates suggest Grăunceanu is > 1.95 Ma, making this site one of the best-dated early hominin localities in Europe. Environmental reconstructions based on isotopic analyzes of horse dentition suggest Grăunceanu would have been relatively temperate and seasonal, demonstrating a wide habitat tolerance in even the earliest hominins in Eurasia. Our results, presented along with multiple other lines of evidence, point to a widespread, though perhaps intermittent, presence of hominins across Eurasia by at least 2.0 Ma.
... Os primeiros representantes do nosso gênero são o Homo habilis e o Homo rudolfensis (Leakey et al., 1964;Groves, 1989). Logo após, ou, para alguns, mais ou menos concomitantemente, surgiu o Homo erectus (Herries et al., 2020). O primeiro foi encontrado inicialmente na Garganta de Olduvai, na Tanzânia e mais tarde no Quênia e está datado por volta de 1.8 milhão de anos. ...
... Quanto ao Homo erectus, este surgiu no registro fóssil há cerca de 1.9 milhões de anos (Herries et al., 2020). Além de ser um bípede estritamente terrestre (na verdade, alguns autores acreditam que ele foi o primeiro a exibir tal característica; Wood e Collard, 1999), já apresentava uma capacidade craniana de cerca de 900 cm 3 em média. ...
... Homo habilis had a mostly plant-based diet with fruits as an important source of food but was one of the earliest species to incorporate meat into its diet, likely through scavenging rather than active hunting (Andrews and Johnson 2020). Over time, Homo erectus (ergaster), which emerged around 1.9 million years ago (Herries et al. 2020;Antón et al. 2023) and migrated out of Africa via the Levantine corridor and Horn of Africa to Eurasia, developed more advanced tools, allowing for increased reliance on meat. These contributed to significant "biological changes, such as the decreases in tooth and gut sizes, the changes in intestinal morphology, and the resultant increases in body and brain sizes-that eventually led to the modern human" (Magkos 2022). ...
Human nutrition represents a dynamic interplay between biological evolution and cultural development, profoundly shaping dietary practices and health outcomes. This paper traces the dietary evolution of the genus Homo, from practices like foraging, scavenging, hunting, and gathering to the Neolithic transition towards agropastoral subsistence. These changes influenced human biology, evident in genetic adaptations such as lactase persistence and amylase gene copy variation, and reshaped societal structures and population dynamics. Cultural phenomena, including food rituals and dietary norms, further shaped community identities and nutritional habits. However, industrialization and globalization have introduced new challenges, including obesity and diet-related non-communicable diseases, driven by processed food consumption and sedentary lifestyles. These issues are exacerbated by ancestral genetic predispositions, such as the “thrifty gene” hypothesis, which links evolutionary adaptations to modern health disparities in specific populations. Advances in nutrigenomics and personalized nutrition provide promising avenues for tailoring dietary interventions to individual genetic profiles, promoting health and preventing chronic diseases. Artificial intelligence (AI) offers innovative tools for diet assessment, tracking, and personalized guidance, presenting opportunities to address global health disparities. However, these technological advancements must navigate ethical concerns, data privacy issues, and cultural sensitivities. By taking into account biological, cultural, and technological perspectives, this study emphasizes the importance of integrating anthropological and nutritional sciences in addressing modern health challenges. It highlights the role of cultural practices in shaping dietary behaviour and advocates for interdisciplinary collaboration to ensure culturally sensitive, equitable nutrition strategies.
... At the other end of the spectrum, one considers non-human primate calls, and the speech capacities of early hominin physiology during the evolution from PL to ML. Neanderthals likely had speech capacities similar to modern H. sapiens (see the discussion in Lieberman & Crelin, 1971;Albanese, 1994;Lieberman, 2002;Boë et al., 2007;Barney et al., 2012;Conde-Valverde et al., 2021). Given the blurry distinction and lineage between Australopithecus and Homo (Bruner & Baudet, 2023;Herries et al., 2020;Kimbel & Villmoare, 2026), the linguistic capacities of early members of Homo remain uncertain, though see MacLarnon & Hewitt (1999), Meyer et al. (2006) and Tobias (1998). On gauging the phonetics and origin of protospeech by studying other primates and the evolution of "speech organs" in general, the reader is referred to Boë et al. (2017). ...
This paper documents an experimental reconstruction of a protolanguage. Combining research from diverse fields such as phonology, syntax and archaeology, we construct a plausible and expressive protolanguage vocabulary of 170 words, and provide examples of the protolanguage in use. We thus obtain a direct, reverse-engineered insight into the evolution from protolanguage to modern language.
... Some of the earliest probable fossils of H. erectus are the ~2.04 Ma cranium found at Drimolen, South Africa (Herries et al., 2020) and ~2 Ma mandible at Melka Kunture, Ethiopia (Mussi et al., 2023), while the earliest generally accepted evidence of their presence out of Africa was discovered at Dmanisi, Georgia, and dated to ~1.8 Ma (Ferring et al., 2011;Lordkipanidze et al., 2013). ...
... The block samples were then cut into standard 2.5 cm 2 cubes in the laboratory. Following Herries et al. (2020), sub-samples from each of these layers were subjected to a range of magnetic cleaning strategies including alternating field (AF), thermal (TH) and a hybrid AF/TH demagnetization. All samples were measured on an AGICO JR6 spinner magnetometer within a magnetic measurements shielded room. ...
... In our assessment, enough of the inferior bevelled edge of the right parietal ( Figure 1) is preserved to indicate that the temporal and parietal portions of the squamosal suture would not have overlapped extensively, unlike the extensive overlap seen in both adult and juvenile Paranthropus. [30][31][32] Finally, contra Kimbel et al. 20 , the very wide separation of the superior temporal lines on the frontal bone argues against the inference that a frontal trigon would have developed in adulthood. ...
Classic depictions of human evolutionary ecology cast Homo as predator and other hominins, including Paranthropus robustus, as prey. Such hypotheses rest on a small number of fossils that exhibit evidence of carnivore predation, including the iconic SK 54 cranium from Swartkrans in South Africa. Here we demonstrate that the SK 54 cranium shares its closest affinities with H. erectus sensu lato rather than P. robustus. Demonstrating that Homo was prey for leopards at Swartkrans weakens the historically significant hypothesis that Homo was better able to avoid predation because of being behaviourally and technologically advanced compared to Paranthropus. Subsequent ideas about hominin palaeobiology derived from this hypothesis warrant reconsideration.
... Os registros mais antigos do Homo erectus têm em torno de 1,8-2 milhões de anos (Herries et al., 2020); consequentemente, os artefatos encontrados na China e na Jordânia são, respectivamente, 100 e 500 mil anos mais antigos que os primeiros fósseis classificados nessa espécie. Nenhum dos sítios com instrumentos líticos anteriores ao material encontrado em Dmanisi preservam fósseis hominínios, impossibilitando a identificação de seus autores. ...
... Se estimaba que su aparición rondaría -o sería algo superior-a los 1,8 Ma. Los ejemplos más antiguos de Homo erectus habían sido señalados en la cueva sudafricana de Drimolen (DNH 134) o en la región del Koobi Fora en la orilla este del lago Turkana (KNM-ER 2598) (Hammond et al., 2021;Herries et al., 2020). Fuera de África tenemos unos muy buenos ejemplos de formas tempranas de este taxón en los ejemplares del yacimiento georgiano de Dmanisi en edades próximas a 1. 8 Ma (Anton, 2013). ...
... Multiple hominin species (Homo, "robust" australopiths, and later australopiths)' and Oldowan stone tools and evidence of carnivory are known from a number of sites in South Africa (such as Swartkrans, Drimolen, and perhaps Gladysvale) (Herries et al. 2020, although see recent research by Zannolli and colleagues 2022, which questions the assignment of some teeth to Homo, notably at Drimolen) and in eastern Africa (Olduvai Gorge, Turkana Basin, and Konso), indicating that the different hominin species had the potential for encounters in their shared home ranges across a span that lasted at least 0.5 million years. It is tempting to think that the dentognathic specializations of the "robust" australopiths is a response to reducing competition for dietary resources by niche partitioning with the sympatric stone tool-using, more carnivorous Homo. ...
Paleontological field research conducted during recent decades has led to the discovery of many new hominin fossils that document the remarkable taxonomic diversity and distinctive paleobiology of our earliest ancestors. The anatomical and behavior transition to bipedality by hominins required significant reorganization of the musculoskeletal system that is unique among mammals. Australopithecus africanus was the first truly ancient hominin known when it was discovered in 1924. Australopithecus bahrelghazali is notable for expanding the range of australopiths beyond eastern and South Africa into the paleo‐Lake Chad basin in North–Central Africa. The biogeography of the earliest hominins remains poorly known and requires paleontological prospecting in new areas throughout Africa – work that is best identified through the use of remote imaging and geospatial data analysis.
... The earliest H. erectus finds predate the advent of the Acheulian technology, with the Drimolen Quarry cranium in South Africa dating to ~2.04-1.95 Ma (Herries et al., 2020). The earliest finds of H. erectus in East Africa come from KNM-ER 2598 at ~1.9 Ma (Hammond et al., 2021). ...
We propose a transmission time investment model for integrating the tenets of human behavioral ecology and cultural evolutionary theory to investigate agency and optimality in the social transmission of lithic technologies. While the cultural transmission process is often overlooked in discussions of optimality, we view it as a critical area for the application of adaptive reasoning to further understand the mechanisms responsible for change in lithic technologies. The proposed model modifies a technological intensification model based on the marginal value theorem (Bettinger et al. Journal of Archaeological Science, 33(4), 538–545, 2006; Mohlenhoff and Codding Evolutionary Anthropology, 26(5), 218–227, 2017) to explore how transmissibility may have affected the complexity of socially transmitted lithic production systems during the Pleistocene. This transmission investment model is contrasted with a passive demographic model derived from traditional explanations for changes in lithic technologies. To highlight how optimal considerations of transmissibility may have affected the long-term evolution of lithic technologies, we apply this model to three Pleistocene archaeological case studies investigating increases and decreases in lithic technological complexity. We propose that technological changes in each of these case studies is consistent with the predictions of the model, suggesting that time management strategies may have played a role in the long-term evolution of Pleistocene technologies. It is unlikely that transmission constraints alone were wholly responsible for the observed patterns, and future research should refine the measures of time availability and cost used here, as well as explore the interplay between transmission investment and other optimizing and social constraints.
... According to the confrontational scavenging hypothesis, protolinguistic 'Adam' belonged to H. erectus [17]. It is remarkable that the latest find in South Africa suggests that H. erectus is at least about 2.04-1.95 million years old, and that the analysis of other hominin species there and the high taxonomic diversity of also non-hominin species indicate a period of climatic variability [39]. In this setting H. erectus faced challenges that exerted strong selection pressure on the population. ...
A dynamic model and an agent-based simulation model implementing the assumptions of the confrontational scavenging hypothesis on early protolanguage as an adaptive response of Homo erectus to gradual change in their habitat has been developed and studied. The core assumptions of the hypothesis and the model scenario are the pre-adaptation of our ancestors to occupy the ecological niche that they constructed for themselves by having evolved displaced communication and a rudimentary tool manufacture, two features allowing them to use a new, concentrated and abundant resource—megafauna carrion—on the savannahs replacing arboreal habitats owing to the drying climate of East Africa at about 2 Ma. The shift in diet required coordinated cooperation by the hominin scavengers confronted with concurrent predators. Power scavenging compelled displaced symbolic communication featuring a limited semantic range; syntax was not yet required. We show that phenotypic evolution on the accuracy of information transfer between cooperating hominins is a necessary and sufficient condition for the population of agents to survive the diet shift. Both the individual and the group fitness of the hominin horde increased with the accuracy of their protolanguage, with decreasing time allocated to foraging and thus more time left for culture.
This article is part of the theme issue ‘Human socio-cultural evolution in light of evolutionary transitions’.
... Igualmente, cualquier cambio en el contexto sedimentario de la nuestra (retrabajamiento; modificaciones de las condiciones geoquímicas) impide su datación (ver sección 3.3.). Hay ejemplos de datación de dientes fósiles > 2 Ma en yacimientos arqueológicos de Suráfrica (Schwarcz et al., 1994;Herries et al. 2020), mientras Laurent et al. (1998) dataron cuarzos procedentes de depósitos miocenos del norte de Francia. En comparación, la datación ESR de espeleotemas de la Cueva del Vallonnet permitió alcanzar edades de hasta unos 1,4 Ma (Yokoyama et al., 1988). ...
Enlace al Vol. Completo: https://recyt.fecyt.es/index.php/CUGEO/issue/view/4351/847
El presente número especial se centra en la mayoría de los métodos de datación que nos pueden ofrecer fechas numéricas y sus correspondientes errores para los materiales Cuaternarios. Los diferentes artículos recogen las técnicas más novedosas o punteras, aunque las más comúnmente usadas en el estudio del Cuaternario, como el Paleomagnetismo, Potasio-Argón (K/Ar) o Carbono 14 (C14) no se han incluido. Esto ha sido debido a que los especialistas con los que se había contactado para la redacción de estos artículos desgraciadamente no pudieron concretar su participación por diferentes motivos. En cualquier caso, son de los métodos más antigua y comúnmente usados en el estudio del Cuaternario, y de sobra conocidos por la mayoría de cuaternaristas, existiendo diferentes obras de referencia para los mismos, aunque no sea en castellano.
La presente obra recoge casi una veintena de métodos que, de una u otra forma, nos aportan fechas y edades numéricas con un importante bagaje geocronológico y apoyo isotópico, geoquímico, biogeoquímico o arqueológico. Partimos de las dataciones epigráficas, cerámicas o numismáticas que nos ofrece la arqueología (01. Campos et al.) para adentrarnos en los métodos arqueomagnéticos (02. Carrancho et al.), dendrocronológicos (03. Génova-Fuster y Díez-Herrero), liquenométricos
(04. Pérez-López) y de estudio de sedimentos varvados (05. Corella y Martín-Puerta) que nos permiten fechar materiales, formas, procesos y eventos energéticos históricos, holocenos o de edad post-glaciar. La contribución de (06.) Cearreta et al., nos explica de qué manera el análisis de radionucleidos de vida corta como el Plomo (210Pb), Cesio (137Cs) o Plutonio (239,240Pu) ayuda en la datación de procesos geológicos muy recientes, especialmente aquellos relacionados con procesos de contaminación y/o del estudio del todavía “nonato” Antropoceno.
Los dos siguientes artículos nos ofrecen cómo se pueden combinar fechas procedentes de diferentes métodos de datación (C14; Th/U, TL, OSL, etc.) para el establecimiento de “modelos cronológicos robustos” que profundicen en las tasas de sedimentación de zonas lagunares y sus implicaciones paleoclimáticas (07. Moreno et al.), o para el establecimiento de cronologías fiables mediante la
generación de “cronofunciones” (08. Silva y Roquero) que relacionen fechas y alturas relativas de terrazas fluviales u otros elementos geomorfológicos, ofreciéndonos marcos geocronológicos regionales “low-cost”.
Bardají y Lario (09. y 10.) ahondan en los principios de la “estratigrafía isotópica marina” (Marine Isotopic Stages), mostrándonos las bases y actualizaciones más recientes de tales escalas isotópicas, con especial referencia al último ciclo glaciar (MIS 4 - MIS 1): estadiales e interestadiales de Groenlandia; Eventos Dansgaard-Oeschger y Eventos Heinrich.
Los siguientes artículos se basan en el uso de los estudios micropaleontológicos como herramienta de datación, tanto en estudios de sondeos marinos (11. Alonso-García et al.), como en registros continentales lacustres o de rellenos kársticos fundamentalmente (12. Cuenca-Bescós). Tanto el estudio de microforaminíferos como de micromamíferos no nos aportan una cronología “sensu stricto” por sí mismos, pero su combinación con dataciones o curvas isotópicas relacionadas permiten el establecimiento de marcos cronológicos robustos para sondeos marinos, continentales y secuencias kársticas. Los primeros son muy importantes para el último ciclo interglaciar-glaciarinterglaciar, y las segundas, relevantes en el establecimiento de cronologías alrededor del tránsito Pleistoceno inferior-medio y más antiguas. . El siguiente artículo aborda la datación isotópica Th/U (13. Múñoz-García y Martín-Chivelet) todo un “tótem” de la geocronología del Cuaternario que se ha aplicado a sistemas kársticos (espeleotemas), terrazas marinas (gasterópodos), corales, calcretas y demás materiales geológicos con un
contenido importante y de precipitación primaria de CO3Ca. A continuación, se aborda la técnica de datación por “racemización de aminoácidos” (14. Torres et al.), que analiza la degradación de aminoácidos en elementos de origen biológico muy diversos, como foraminíferos, moluscos, crustáceos, y diferentes tipos de fósiles de mamíferos (huesos y dientes), lo que permite establecer cronologías en secuencias difícilmente datables por otros métodos. Es una técnica no muy utilizada, pero ampliamente aplicada en España debido al trabajo del Laboratorio de Estratigrafía Biomolecular de la Universidad Politécnica de Madrid (UPM).
La siguiente dupla de artículos se ocupa del análisis de dos de las técnicas de datación más modernamente introducidas en España, y de amplio uso en la actualidad, como son la “Termoluminiscencia y la Termoluminiscencia Ópticamente Estimulada”, TL y OSL en sus siglas convencionales (15. Medialdea- Utande y García-Silva) y la “Resonancia Paramagnética Electrónica”, ESR (16. Duval). La versatilidad de estas técnicas de datación al no requerir materiales específicos, sino más bien ampliamente distribuidos sobre la corteza terrestre, como son granos de cuarzo y feldespato, es la que ha hecho que estas sean las herramientas geocronológicas que han multiplicado exponencialmente el número de dataciones disponibles en España. A ello se le une la disponibilidad de análisis en los laboratorios de datación del Centro Nacional para el Estudio de la Evolución Humana (CENIEH) al que pertenecen los primeros firmantes de ambos artículos. Un último artículo (17. Alcalá Reygosa et al.) nos ilustra en las más modernas aplicaciones de la “datación por cosmogénicos terrestres de materiales y formas volcánicas recientes”, comentándonos algunos ejemplos en volcanes monogenéticos holocenos de México.
Todos los trabajos han sido revisados por pares, incluyendo un importante elenco de investigadores que han actuado como revisores.
... Igualmente, cualquier cambio en el contexto sedimentario de la nuestra (retrabajamiento; modificaciones de las condiciones geoquímicas) impide su datación (ver sección 3.3.). Hay ejemplos de datación de dientes fósiles > 2 Ma en yacimientos arqueológicos de Suráfrica (Schwarcz et al., 1994;Herries et al. 2020), mientras Laurent et al. (1998) dataron cuarzos procedentes de depósitos miocenos del norte de Francia. En comparación, la datación ESR de espeleotemas de la Cueva del Vallonnet permitió alcanzar edades de hasta unos 1,4 Ma (Yokoyama et al., 1988). ...
Resumen. Este trabajo pretende proporcionar una visión general del método de datación por Resonancia Paramagnética Electrónica (más conocido por su acrónimo ingles ESR procedente de Electron Spin Resonance), presentando sus principios básicos, su potencial y límites actuales. La ESR es un método paleodosimétrico, al igual que la luminiscencia. Se basa en la cuantificación de la dosis de radiación absorbida por la muestra a lo largo del tiempo debido a su exposición a la radiactividad natural. La ESR compensa una precisión menor respecto a otros métodos de referencia como el C 14 , Ar/Ar o U/Th, por una gran versatilidad de aplicación. Permite datar materiales muy diversos (p.ej., carbonatos, fosfatos, silicatos, sulfatos) como probablemente ningún otro mé-todo, aunque la datación de cuarzos y dientes fósiles son aplicaciones mucho más populares que las demás. Finalmente, además de su interés en geocronología, la técnica de ESR ha demostrado su utilidad en varios estudios del Cuaternario como en trabajos de termocronometria y paleotemperaturas, o para caracterizar cuarzos y determinar su origen. Palabras clave: datación por Resonancia Paramagnética Electrónica; datación por Resonancia de Espín Elec-trónico; carbonatos, fosfatos, silicatos, sulfatos.
Abstract. This paper intends to provide an overview of the basic principles, potential and current limitations of the Electron Spin Resonance (ESR) dating method. Like Luminescence dating, ESR is a palaeodosimetric method based on the evaluation and quantification of the radiation dose absorbed by a sample resulting from its prolonged exposure to natural radioactivity. Despite a lower precision compared to other more established methods like 14 C, U-series or Ar/Ar, ESR offers an unbeatable versatility. It can date a wide range of materials (e.g., carbonates, phosphates, silicates or sulfates), although ESR dating of fossil teeth and quartz grains are En prensa In press
In this chapter, I trace the African origins of the earliest hominins from 3.7 mya to about 1.6 mya. A driving force throughout the period was a trend toward a cooler and more variable climate. I present a framework for analyzing the co-evolution of factors of production over prehistory, including key factors such as the natural environment, human capital, social capital, physical capital, and technological knowledge. Based on that framework, I review discussions concerning the emergence of bipedalism and the origins of physical capital (stone tools). The morphology of Homo ergaster/erectus (around 2 mya), featuring a small gut and long limbs, was potentially made possible by the use of fire and cooking. These major innovations presumably paved the way for the first wave of hominin migration out of Africa.
The significance of the archaeological record unearthed in the SHK fluvial landscape represents a noteworthy dataset to study in greater detail the expression of inter-assemblage variability during the formally labelled Developed Oldowan/Acheulean interface in Olduvai Gorge. A precise stratigraphic interval, laterally continuous, and preserving fractions of anthropogenic activity at different points of the same fluvial network makes it feasible to identify the variable techno-economic ways in which hominins responded to the local paleo-landscape in a short time unit. In this work we present the results of the comparative techno-economic study of the three lithic collections retrieved from the time unit defined by an isochronous litho-stratigraphic volcanic horizon deposited in the fluvial landscape of SHK Main site and SHK Extension. The combined use of this isochrone plus the archaeo-stratigraphic method to refine time-averaging constraints offers for the first time an assessment of the nature of technological variation within different fractions of the same fluvial landscape at ~ 1.5 Ma in Middle Bed II. The goal of this analysis is to look closely at inter-assemblage variability in a unit of time with a coherent degree of synchronicity and to add new data to the Developed Oldowan/Acheulean gradient.
This paper presents a detailed analysis of the endocast of one of the most complete Paranthropus robustus crania known, DNH 7, from the Drimolen site (South Africa), and compares it with the morphology of other australopithecine endocasts. We focus on endocranial volume, the impressions of cortical sulci, cranial sutures, and the pattern of cranial venous sinuses on the endocast. A noteworthy observation is the estimated endocranial capacity of 403 cm ³ , which is small for an adult Paranthropus . Fragmentary sulci identified in the frontal and temporal lobes of DNH 7 exhibit similarities with patterns observed in chimpanzees and gracile australopithecines. We observe the presence of a large remnant of an occipital‐marginal sinus on DNH 7 and provide an updated table of 13 Paranthropus endocasts that are scorable for this trait, which reinforces the hypothesis that an enlarged occipital‐marginal (O/M) sinus system was fixed across the three species of Paranthropus . In light of this, the possible functional significance of the occipital‐marginal sinus system is reevaluated considering the ontogenetic development of cranial venous blood flow in human children. This leads us to hypothesize that the ontogenetic development of cranial blood flow in Paranthropus and Australopithecus africanus infants were different and to suggest that Taung 1 was the only A. africanus specimen known to have exhibited an enlarged O/M sinus system because it was an immature individual.
Bolt’s Farm is the name given to a series of non-hominin bearing fossil sites that have often been suggested to be some of the oldest Pliocene sites in the Cradle of Humankind, South Africa. This article reports the results of the first combined Uranium-Series and Electron Spin Resonance (US-ESR) dating of bovid teeth at Milo’s Cave and Aves Cave at Bolt’s Farm. Both tooth enamel fragments and tooth enamel powder ages were presented for comparison. US-ESR, EU and LU models are calculated. Overall, the powder ages are consistent with previous uranium-lead and palaeomagnetic age estimates for the Aves Cave deposit, which suggest an age between ~3.15 and 2.61 Ma and provide the first ages for Milo’s Cave dates to between ~3.1 and 2.7 Ma. The final ages were not overly dependent on the models used (US-ESR, LU or EU), which all overlap within error. These ages are all consistent with the biochronological age estimate (<3.4–>2.6 Ma) based on the occurrence of Stage I Metridiochoerus andrewsi . Preliminary palaeomagnetic analysis from Milo’s Cave indicates a reversal takes place at the site with predominantly intermediate directions, suggesting the deposit may date to the period between ~3.03 and 3.11 Ma within error of the ESR ages. This further suggests that there are no definitive examples of palaeocave deposits at Bolt’s Farm older than 3.2 Ma. This research indicates that US-ESR dating has the potential to date fossil sites in the Cradle of Humankind to over 3 Ma. However, bulk sample analysis for US-ESR dating is recommended for sites over 3 Ma.
An uncritical reliance on the phylogenetic species concept has led paleoanthropologists to become increasingly typological in their delimitation of new species in the hominin fossil record. As a practical matter, this approach identifies species as diagnosably distinct groups of fossils that share a unique suite of morphological characters but, ontologically, a species is a metapopulation lineage segment that extends from initial divergence to eventual extinction or subsequent speciation. Working from first principles of species concept theory, it is clear that a reliance on morphological diagnosabilty will systematically overestimate species diversity in the fossil record; because morphology can evolve within a lineage segment, it follows that early and late populations of the same species can be diagnosably distinct from each other. We suggest that a combination of morphology and chronology provides a more robust test of the single‐species null hypothesis than morphology alone.
The phylogenetic position of Homo habilis is central to debates over the origin and early evolution of the genus Homo. A large portion of the species hypodigm consists of dental remains, but they have only been studied at the often worn enamel surface. We investigate the morphology of the H. habilis enamel-dentine junction (EDJ), which is preserved in cases of moderate tooth wear and known to carry a strong taxonomic signal. Geometric morphometrics is used to characterise dentine crown shape and size across the entire mandibular and maxillary tooth rows, compared with a broad comparative sample (n = 712). We find that EDJ morphology in H. habilis is for the most part remarkably primitive, supporting the hypothesis that the H. habilis hypodigm has more in common with Australopithecus than later Homo. Additionally, the chronologically younger specimen OH 16 displays a suite of derived features; its inclusion in H. habilis leads to excessive levels of variation.
In Africa, the scarcity of hominin remains found in direct association with stone tools has hindered attempts to link Homo habilis and Homo erectus with particular lithic industries. The infant mandible discovered in level E at Garba IV (Melka Kunture) on the highlands of Ethiopia is critical to this issue due to its direct association with an Oldowan lithic industry. Here we use synchrotron imaging to examine the internal morphology of the unerupted permanent dentition and confirm its identification as Homo erectus. Additionally, we utilize new palaeomagnetic ages to show that 1) the mandible in level E is ca. 2 million-years-old, and represents one of the earliest Homo erectus fossils, and 2) that overlying level D, ca. 1.95 million-years-old, contains the earliest known Acheulean assemblage.
Which hominins are responsible for creating the Pleistocene archaeological record of Africa? Given that tool use has been recorded through paleontological and archaeological records over the last approximately 2.5 million years (Myr), we know that multiple hominin species must be involved in technological innovations at different times and locations. Although tool use and manufacture were once considered unique characteristics of our own genus (Homo), the last few decades have shown us that there may be archaeological evidence of tool use before the genus Homo (McPherron et al., 2010; Harmand et al., 2015). Another intractable issue is that it is nearly impossible to know whether archaeological materials and hominins are related to one another, even if found in situ at the same site. There are many lines of evidence that might mislead an association between hominin remains and archaeology: hominins can scavenge and repurpose tools, have late access to an already butchered carcass, or be preserved at a location where tools were either discarded by another hominin species or accumulated through other taphonomic processes. In short, identifying which hominins are responsible for the archaeological record is not always clear-cut. Here, we briefly discuss the 11 species of hominins currently recognized in Africa during the Pleistocene, selected by virtue of their temporal placement within the Pleistocene span (2.58 million years ago (Ma) to 11 thousand years ago (ka), the focal period of the volume) and their direct and indirect associations with tool-making capacity. For readership’s sake, we list the main traits (both derived and primitive) that distinguish the featured taxa in Table 1. Although all of these species may have been contributors to the archaeological record of Africa during the Pleistocene, only a handful seem to be unequivocally linked to tool use or manufacture.
More than 150 hominin teeth, dated to ∼330-241 thousand years ago, were recovered during the 2013-2015 excavations of the Dinaledi Chamber of the Rising Star cave system, South Africa. These fossils comprise the first large single-site sample of hominin teeth from the Middle Pleistocene of Africa. Though scattered remains attributable to Homo sapiens, or their possible lineal ancestors, are known from older and younger sites across the continent, the distinctive morphological feature set of the Dinaledi teeth supports the recognition of a novel hominin species, Homo naledi. This material provides evidence of African Homo lineage diversity that lasts until at least the Middle Pleistocene. Here, a catalog, anatomical descriptions, and details of preservation and taphonomic alteration are provided for the Dinaledi teeth. Where possible, provisional associations among teeth are also proposed. To facilitate future research, we also provide access to a catalog of surface files of the Rising Star jaws and teeth.
Ontogeny provides critical information about the evolutionary history of early hominin adult morphology. We describe fossils from the southern African sites of Kromdraai and Drimolen that provide insights into early craniofacial development in the Pleistocene robust australopith Paranthropus robustus. We show that while most distinctive robust craniofacial features appear relatively late in ontogeny, a few do not. We also find unexpected evidence of independence in the growth of the premaxillary and maxillary regions. Differential growth results in a proportionately larger and more postero-inferiorly rotated cerebral fossa in P. robustus infants than in the developmentally older Australopithecus africanus juvenile from Taung. The accumulated evidence from these fossils suggests that the iconic SK 54 juvenile calvaria is more likely early Homo than Paranthropus. It is also consistent with the hypothesis that P. robustus is more closely related to Homo than to A. africanus.
The Turkana Basin in Kenya/Ethiopia hosts remarkable fossil-rich sediments that are central to our understanding of early hominin evolution, with interbedded volcanic tuffs providing critical time markers. However, the resolution of existing Early Pleistocene/Pliocene ages is limited to ∼20-60 kyr, inhibiting evaluation of climatic/environmental drivers of evolution. Here, we present high precision, single-feldspar ⁴⁰ Ar/ ³⁹ Ar age and elemental data for four stratigraphically significant tuffs. These samples exhibit variably dispersed age distributions correlated with feldspar compositional trends, interpreted to indicate partial retention of inherited argon, related to crustal ‘cold storage’ and rapid melt infiltration preceding eruption. We evaluated various statistical methods and calculate astronomically calibrated, Bayesian age estimates of 1879.1 ± 0.6 ka (± 2.4 ka including external errors) for the KBS/H2 Tuff, 1837.4 ± 0.9 ka (± 2.4 ka) for the Malbe/H4 Tuff, 1357.5 ± 1.8 ka (± 2.5 ka) for the Chari/L Tuff and 1315.4 ± 1.9 ka (± 2.5 ka) for the Gele Tuff. Our results permit refined age constraints for important early Homo fossils, including the cranium KNM-ER1813 ( Homo habilis ) and various Homo erectus fossils. The KBS Tuff age also provides an important calibration locus for orbital tuning of paleoclimate proxy records, revealing complex interplay between paleoclimate and geological drivers of sedimentation.
Supplementary material: https://doi.org/10.6084/m9.figshare.c.6602994
In celebration of the 50th anniversary of the Journal of Human Evolution, we re-evaluate the fossil record for early Homo (principally Homo erectus, Homo habilis, and Homo rudolfensis) from early diversification and dispersal in the Early Pleistocene to the ultimate demise of H. erectus in the early Middle Pleistocene. The mid-1990s marked an important historical turning point in our understanding of early Homo with the redating of key H. erectus localities, the discovery of small H. erectus in Asia, and the recovery of an even earlier presence of early Homo in Africa. As such, we compare our understanding of early Homo before and after this time and discuss how the order of fossil discovery and a focus on anchor specimens has shaped, and in many ways biased, our interpretations of early Homo species and the fossils allocated to them. Fragmentary specimens may counter conventional wisdom but are often overlooked in broad narratives. We recognize at least three different cranial and two or three pelvic morphotypes of early Homo. Just one postcranial morph aligns with any certainty to a cranial species, highlighting the importance of explicitly identifying how we link specimens together and to species; we offer two ways of visualizing these connections. Chronologically and morphologically H. erectus is a member of early Homo, not a temporally more recent species necessarily evolved from either H. habilis or H. rudolfensis. Nonetheless, an ancestral-descendant notion of their evolution influences expectations around the anatomy of missing elements, especially the foot. Weak support for long-held notions of postcranial modernity in H. erectus raises the possibility of alternative drivers of dispersal. New observations suggest that the dearth of faces in later H. erectus may mask taxonomic diversity in Asia and suggest various later mid-Pleistocene populations could derive from either Asia or Africa. Future advances will rest on the development of nuanced ways to affiliate fossils, greater transparency of implicit assumptions, and attention to detailed life history information for comparative collections; all critical pursuits for future research given the great potential they have to enrich our evolutionary reconstructions for the next fifty years and beyond.
Waypoint 160 is a paleocave at Bolt's Farm in the 'Cradle of Humankind,' South Africa. It is known for the novel murid taxa Eurotomys bolti, argued to be morphologically intermediate between Eurotomys pelomyoides from Langebaanweg (∼5.1 Ma) and the earliest Otomyinae from Makapansgat Limeworks (∼3.0-2.6 Ma). Based on the presence of this specimen, an age of ∼4.5 Ma was inferred for Waypoint 160, making it far older than other Cradle sites. This biochronological age was used to argue that Parapapio and Cercopithecoides fossils from Waypoint 160 were the oldest in the region. Here, we provide a detailed sedimentological context for the in-situ deposits at Waypoint 160. We have identified interior cave deposits, in contrast to other sites at Bolt's Farm. Petrography confirms that one unit (facies D) contains in-situ microfaunal fossils, indicating the likely provenience of the E. bolti specimen. Palaeomagnetic analysis shows four periods of magnetic polarity in the sequence. Using U-Pb ages as chronological pins, we argue that the upper part of the sequence records a polarity change at the end of the Olduvai subChron (1.78 Ma). The lower part of the sequence records a polarity shift from normal to reversed that likely relates to the Feni subChron (2.16-2.12 Ma), based on a basal flowstone U-Pb age of 2.269 ± 0.075 Ma. Together this points to a depositional window of ∼500 ka, with the Parapapio and E. bolti tentatively attributed to the micromammal fossil-bearing layers dating to ∼2.27-2.07 Ma. This has significant implications for other biochronological dates in South Africa, as E. bolti is now less than ∼2.27 Ma, younger than the oldest Otomyinae at Makapansgat Limeworks and thus not ancestral to them. This chronology for Waypoint 160 challenges the presence of older, early to mid-Pliocene deposits >3.20 Ma in the Gauteng portion of the Cradle.
Humans are unique among terrestrial mammals in our manner of walking and running, reflecting 7 to 8 Ma of musculoskeletal evolution since diverging with the genus Pan. One component of this is a shift in our skeletal muscle biology towards a predominance of myosin heavy chain (MyHC) I isoforms (i.e. slow fibers) across our pelvis and lower limbs, which distinguishes us from chimpanzees. Here, new MyHC data from 35 pelvis and hind limb muscles of a Western gorilla (Gorilla gorilla) are presented. These data are combined with a similar chimpanzee dataset to assess the MyHC I content of humans in comparison to African apes (chimpanzees and gorillas) and other terrestrial mammals. The responsiveness of human skeletal muscle to behavioral interventions is also compared to the human-African ape differential. Humans are distinct from African apes and among a small group of terrestrial mammals whose pelvis and hind/lower limb muscle is slow fiber dominant, on average. Behavioral interventions, including immobilization, bed rest, spaceflight and exercise, can induce modest decreases and increases in human MyHC I content (i.e. -9.3% to 2.3%, n = 2033 subjects), but these shifts are much smaller than the mean human-African ape differential (i.e. 31%). Taken together, these results indicate muscle fiber content is likely an evolvable trait under selection in the hominin lineage. As such, we highlight potential targets of selection in the genome (e.g. regions that regulate MyHC content) that may play an important role in hominin skeletal muscle evolution.
Humans evolved in Africa over millions of years. This history is revealed through fossils and artifacts, application of the geosciences, and analysis of ancient DNA and proteins. Relative to an antecedent species of Australopithecus , Homo is characterized by an increase in encephalization, reduction of the posterior dentition, larger body size, greater mobility, and the capacity to make tools and process food. This chapter lists early Homo specimens from African localities. The brain of H. habilis has been characterized as larger than in australopiths but small relative to that of other Homo species. Homo rudolfensis was named by Valery Alexeev in 1986, with KNM‐ER 1470 later designated as the type. This ca. 2.06 Ma old cranium presents facial features that are Australopithecus ‐like, and the cheek teeth may have been quite large.
Archaeomagnetic dating is the study of the past magnetic field of the Earth, as recorded by fired archaeological materials and sediments, and interpreting this information to date past events. The Earth's magnetic field is most easily recognized by the effect it has on a magnetized compass needle, causing it to point to magnetic north. Most archaeomagnetic studies concern in situ fired structures such as kilns, ovens, hearths, furnaces, and burned floors. In order to produce an archaeomagnetic date, the selected material must be sampled, its magnetic properties assessed in the laboratory, and then that measurement compared with a dated record of geomagnetic change to produce a calendar date. The main application of archaeomagnetic investigations is to provide calendar dates for archaeological events and sequences. This requires an established secular variation record for the period and region concerned.
Humans have undergone several anatomical adaptations throughout evolution. Paleontological records are a prime method of studying these adaptations, but they can unfortunately provide only a limited view of how modifications of 'soft traits' such as brain and cognition have contributed to the emergence of Homo sapiens. An additional approach includes the examination of when genetic variations associated with human phenotypes emerged in our history. Combining data from genome-wide association studies (GWAS) with dating data on the human genome, we systematically analysed the temporal emergence of single-nucleotide polymorphisms (SNPs) associated with modern-day human phenotypes over the last five million years. We show the genetic timeline of human-characteristic phenotypes to follow a distinct pattern with two bursts of genetic variation that co-emerge with milestones in the human lineage. Our findings suggest that SNPs associated with neocortical, neuropsychiatric, and ophthalmological traits appeared relatively recently in hominin evolution, with genes containing recently emerged SNPs linked to intelligence and neocortical area.
Interpreting morphological variation within the early hominin fossil record is particularly challenging. Apart from the fact that there is no absolute threshold for defining species boundaries in palaeontology, the degree of variation related to sexual dimorphism, temporal depth, geographic variation or ontogeny is difficult to appreciate in a fossil taxon mainly represented by fragmentary specimens, and such variation could easily be conflated with taxonomic diversity. One of the most emblematic examples in paleoanthropology is the Australopithecus assemblage from the Sterkfontein Caves in South Africa. Whereas some studies support the presence of multiple Australopithecus species at Sterkfontein, others explore alternative hypotheses to explain the morphological variation within the hominin assemblage. In this review, I briefly summarize the ongoing debates surrounding the interpretation of morphological variation at Sterkfontein Member 4 before exploring two promising avenues that would deserve specific attention in the future, that is, temporal depth and nonhuman primate diversity.
The australopiths are well known from more than a thousand fossils and several skeletons because of the ideal conditions for preserving and delivering fossil in South African caves and the East African Rift Valley. Australopiths were bipedal in their unique ways but differ more strikingly from humans in the enlargement of chewing teeth and associated features. As we examine these fossils closely, we have discerned more species—currently fourteen are under consideration. They are roughly sorted out between the so-called gracile species belonging to Australopithecus and even more robustly built members of genus Paranthropus. This chapter also considers the limitations of preserving and recovering fossils. The worlds of the past are much more poorly sampled than studies of the fossils would suggest
As new fossils were discovered in the 1960s, the substantial gap between Australopithecus and Homo nearly vanished. Cranial capacities were found to overlap and dental characters appeared to grade into one another. This is what one would expect from a continuous evolving lineage. The early members of Homo are now known to represent multiple contemporary species in East Africa, and sorting fossils among them with any certainty is impossible. It is easier to discuss habiline and erectine grades, with the first one a seeming evolutionary dead end and the second closer to our ancestry. The early appearance of humans coincides roughly with the earliest stone tools and with a gradual but significant change in climate and habitat.
Fossils of erectine-grade hominins appear in Africa earlier than in Asia, but the relationship between them is unclear. Morphological changes, including an increase in brain size, are observed in Africa through time, justifying a distinction between the earlier H. ergaster and the later H. heidelbergensis. Nonetheless, considerable variation remains unexplained, and it is uncertain how many lineages coexisted. The recent discovery of H. naledi confirms that at least one small-brained habiline-grade population survived until about 300,000 years ago. Hominins moved between Africa and Europe several times, as indicated by the flow of genes and technology. The first Europeans appear to represent a primitive or transitional form of H. heidelbergensis. The species flourished later and overlapped with or evolved into the Neanderthals. The diversity observed among Middle Pleistocene Europeans may be partly explained by population collapse and repopulation during the Pleistocene glaciation cycles.
We present the most complete foodplant checklist for southern Africa to date, and summarise the geo-chronological origins of the South Africa and Lesotho biomes. Working from Binford's foraging radii, we introduce a 3-tier method for assessing and comparing foodplant fitness landscapes at different scales. To illustrate the method's potential, we analyse the Klasies River landscape starting with a ~12.5 km foraging radius working from the Klasies River Main Site, comparing it with its ~35 km foraging radius. Our comparison reveals a proportional increase of 74.5% in foodplants moving from the smaller to the larger foraging range, with the highest increases in plant foods such as grains, geophytes and seeds. It is therefore reasonable to predict that the Klasies River foragers may have extended their range seasonally, or when needed, to harvest such preservable foods. On a meta scale (compared to foodplant use in current/recent southern Africa, sub-Saharan Africa, the world's economic foodplants and the commercialised food plants of the world), the general limitations, strengths and uniqueness of the Klasies River foodplant fitness landscape is highlighted. Lastly, based on the foodplant checklists for southern Africa and Klasies River, we raise questions about the obligatory cooking hypothesis.
Humans evolved in the dynamic landscapes of Africa under conditions of pronounced climatic, geological and environmental change during the past 7 million years. This book brings together detailed records of the paleontological and archaeological sites in Africa that provide the basic evidence for understanding the environments in which we evolved. Chapters cover specific sites, with comprehensive accounts of their geology, paleontology, paleobotany, and their ecological significance for our evolution. Other chapters provide important regional syntheses of past ecological conditions. This book is unique in merging a broad geographic scope (all of Africa) and deep time framework (the past 7 million years) in discussing the geological context and paleontological records of our evolution and that of organisms that evolved alongside our ancestors. It will offer important insights to anyone interested in human evolution, including researchers and graduate students in paleontology, archaeology, anthropology and geology.
Fossil discoveries of early Australopithecus species from Woranso-Mille have played a significant role in improving our understanding of mid-Pliocene hominin evolution and diversity. Here, we describe two mandibles with dentitions, recovered from sediments immediately above a tuff radiometrically dated to 3.76 ± 0.02 Ma, and assess their taxonomic affinity. The two mandibles (MSD-VP-5/16 and MSD-VP-5/50) show morphological similarities with both Australopithecus anamensis and Australopithecus afarensis. Some of the unique features that distinguish Au. anamensis from Au. afarensis are present in the mandibles, which also share a few derived features with Au. afarensis. Their retention of more Kanapoi Au. anamensis-like traits, compared to the fewer derived features they share with Au. afarensis, and the presence of Au. anamensis at Woranso-Mille in 3.8-million-year-old deposits, lends support to their assignment to Au. anamensis. However, it is equally arguable that the few derived dentognathic features they share with Au. afarensis could be taxonomically more significant, making it difficult to conclusively assign these specimens to either species. Regardless of which species they are assigned to, the mosaic nature of the dentognathic morphology and geological age of the two mandibles lends further support to the hypothesized ancestor–descendant relationship between Au. anamensis and Au. afarensis. However, there is now limited fossil evidence indicating that these two species may have overlapped in time. Hence, the last appearance of Au. anamensis and first appearance of Au. afarensis are currently unknown. Recovery of Australopithecus fossils from 4.1 to 3.8 Ma is critical to further address the timing of these events.
Reversal of Earth’s magnetic field polarity every 10 ⁵ to 10 ⁶ years is among the most far-reaching, yet enigmatic, geophysical phenomena. The short duration of reversals make precise temporal records of past magnetic field behavior paramount to understanding the processes that produce them. We correlate new ⁴⁰ Ar/ ³⁹ Ar dates from transitionally magnetized lava flows to astronomically dated sediment and ice records to map the evolution of Earth’s last reversal. The final 180° polarity reversal at ~773 ka culminates a complex process beginning at ~795 ka with weakening of the field, succeeded by increased field intensity manifested in sediments and ice, and then by an excursion and weakening of intensity at ~784 ka that heralds a >10 ka period wherein sediments record highly variable directions. The 22 ka evolution of this reversal suggested by our findings is mirrored by a numerical geodynamo simulation that may capture much of the naturally observed reversal process.
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 trace-element 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.
Bolt’s Farm is a Plio-Pleistocene fossil site located within the southwestern corner of the UNESCO Hominid Fossil Sites of South Africa World Heritage Site. The site is a complex of active caves and more than 20 palaeokarst deposits or pits, many of which were exposed through the action of lime mining in the early 20th century. The pits represent heavily eroded cave systems, and as such associating the palaeocave sediments within and between the pits is difficult, especially as little geochronological data exists. These pits and the associated lime miner’s rubble were first explored by palaeoanthropologists in the late 1930s, but as yet no hominin material has been recovered. The first systematic mapping was undertaken by Frank Peabody as part of the University of California Africa Expedition (UCAE) in 1947–1948. A redrawn version of the map was not published until 1991 by Basil Cooke and this has subsequently been used and modified by recent researchers. Renewed work in the 2000s used Cooke’s map to try and relocate the original fossil deposits. However, Peabody’s map does not include all the pits and caves, and thus in some cases this was successful, while in others previously sampled pits were inadvertently given new names. This was compounded by the fact that new fossil bearing deposits were discovered in this new phase, causing confusion in associating the 1940s fossils with the deposits from which they originated; as well as associating them with the recently excavated material. To address this, we have used a Geographic Information System (GIS) to compare Peabody’s original map with subsequently published maps. This highlighted transcription errors between maps, most notably the location of Pit 23, an important palaeontological deposit given the recovery of well-preserved primate crania ( Parapapio , Cercopithecoides ) and partial skeletons of the extinct felid Dinofelis . We conducted the first drone and Differential Global Positioning System (DGPS) survey of Bolt’s Farm. Using legacy data, high-resolution aerial imagery, accurate DGPS survey and GIS, we relocate the original fossil deposits and propose a definitive and transparent naming strategy for Bolt’s Farm, based on the original UCAE Pit numbers. We provide datum points and a new comprehensive, georectified map to facilitate spatially accurate fossil collection for all future work. Additionally, we have collated recently published faunal data with historic fossil data to evaluate the biochronological potential of the various deposits. This suggests that the palaeocave deposits in different pits formed at different times with the occurrence of Equus in some pits implying ages of <2.3 Ma, whereas more primitive suids ( Metridiochoerus ) hint at a terminal Pliocene age for other deposits. This study highlights that Bolt’s Farm contains rare South African terminal Pliocene fossil deposits and creates a framework for future studies of the deposits and previously excavated material.
The Cradle of Humankind (Cradle) in South Africa preserves a rich collection of fossil hominins representing Australopithecus, Paranthropus and Homo1. The ages of these fossils are contentious2–4 and have compromised the degree to which the South African hominin record can be used to test hypotheses of human evolution. However, uranium–lead (U–Pb) analyses of horizontally bedded layers of calcium carbonate (flowstone) provide a potential opportunity to obtain a robust chronology5. Flowstones are ubiquitous cave features and provide a palaeoclimatic context, because they grow only during phases of increased effective precipitation6,7, ideally in closed caves. Here we show that flowstones from eight Cradle caves date to six narrow time intervals between 3.2 and 1.3 million years ago. We use a kernel density estimate to combine 29 U–Pb ages into a single record of flowstone growth intervals. We interpret these as major wet phases, when an increased water supply, more extensive vegetation cover and at least partially closed caves allowed for undisturbed, semi-continuous growth of the flowstones. The intervening times represent substantially drier phases, during which fossils of hominins and other fossils accumulated in open caves. Fossil preservation, restricted to drier intervals, thus biases the view of hominin evolutionary history and behaviour, and places the hominins in a community of comparatively dry-adapted fauna. Although the periods of cave closure leave temporal gaps in the South African fossil record, the flowstones themselves provide valuable insights into both local and pan-African climate variability. Climate-driven periodicity of flowstone accretion between 3.2 and 1.3 million years ago in Cradle of Humankind caves reveals that the presence of hominin fossils reflects accumulation in open caves during intermittent, substantially drier phases.
Considerable attention has been paid to dating the earliest appearance of hominins outside Africa. The earliest skeletal and artefactual evidence for the genus Homo in Asia currently comes from Dmanisi, Georgia, and is dated to approximately 1.77-1.85 million years ago (Ma)1. Two incisors that may belong to Homo erectus come from Yuanmou, south China, and are dated to 1.7 Ma2; the next-oldest evidence is an H. erectus cranium from Lantian (Gongwangling)-which has recently been dated to 1.63 Ma3-and the earliest hominin fossils from the Sangiran dome in Java, which are dated to about 1.5-1.6 Ma4. Artefacts from Majuangou III5 and Shangshazui6 in the Nihewan basin, north China, have also been dated to 1.6-1.7 Ma. Here we report an Early Pleistocene and largely continuous artefact sequence from Shangchen, which is a newly discovered Palaeolithic locality of the southern Chinese Loess Plateau, near Gongwangling in Lantian county. The site contains 17 artefact layers that extend from palaeosol S15-dated to approximately 1.26 Ma-to loess L28, which we date to about 2.12 Ma. This discovery implies that hominins left Africa earlier than indicated by the evidence from Dmanisi.
The past two million years of eastern African climate variability is currently poorly constrained, despite interest in understanding its assumed role in early human evolution. Rare palaeoclimate records from northeastern Africa suggest progressively drier conditions or a stable hydroclimate. By contrast, records from Lake Malawi in tropical southeastern Africa reveal a trend of a progressively wetter climate over the past 1.3 million years. The climatic forcings that controlled these past hydrological changes are also a matter of debate. Some studies suggest a dominant local insolation forcing on hydrological changes, whereas others infer a potential influence of sea surface temperature changes in the Indian Ocean. Here we show that the hydroclimate in southeastern Africa (20–25° S) is controlled by interplay between low-latitude insolation forcing (precession and eccentricity) and changes in ice volume at high latitudes. Our results are based on a multiple-proxy reconstruction of hydrological changes in the Limpopo River catchment, combined with a reconstruction of sea surface temperature in the southwestern Indian Ocean for the past 2.14 million years. We find a long-term aridification in the Limpopo catchment between around 1 and 0.6 million years ago, opposite to the hydroclimatic evolution suggested by records from Lake Malawi. Our results, together with evidence of wetting at Lake Malawi, imply that the rainbelt contracted toward the Equator in response to increased ice volume at high latitudes. By reducing the extent of woodland or wetlands in terrestrial ecosystems, the observed changes in the hydroclimate of southeastern Africa—both in terms of its long-term state and marked precessional variability—could have had a role in the evolution of early hominins, particularly in the extinction of Paranthropus robustus.
An apparently unique part of the Earlier Stone Age record of Africa are a series of bone tools dated to between ∼2 and ∼1 Ma from the sites of Olduvai in East Africa, and Swartkrans, Drimolen and Sterkfontein in South Africa. The South and East African bone tools are quite different, with the South African tools having a number of distinct characters formed through utilisation, whereas the East African tools are flaked tools that in some cases mirror stone tool production. The South African bone tools currently consists of 108 specimens from the three sites above. They have been interpreted as being used for digging into homogenous grained soil to access high quality food resources, or as a multi-purpose tools. It has generally been assumed that they were made by Paranthropus robustus, as this species is most often associated with bone tool bearing deposits, especially when high numbers occur. However, early Homo is also found at these sites. Here we report on two fossils from the Paranthopus robustus site of Kromdraai B, which has only yielded one stone tool to date, that have the same characteristic wear patterns as the bone tools identified at other sites. We also describe a small collection (N = 6) of the first stone tools recovered from the bone tool and Paranthropus and early Homo bearing site of Drimolen Main Quarry. These discoveries further increase the association between bone and stone tool technologies in the South African Earlier Stone Age. However, there remains no direct correlation between the occurrence of bone or stone tools and a particular species being found at the different sites. We then review the place of these bone tools within the South African archaeological record. They appear to be a consistent part of the South African record for around a million years or so between <∼2.3 and >∼0.8 Ma. While they change little over this time, they occur with both Oldowan and Acheulian assemblages.
Homo naledi is a previously-unknown species of extinct hominin discovered within the Dinaledi Chamber of the Rising Star cave system, Cradle of Humankind, South Africa. This species is characterized by body mass and stature similar to small-bodied human populations but a small endocranial volume similar to australopiths. Cranial morphology of H. naledi is unique, but most similar to early Homo species including Homo erectus, Homo habilis or Homo rudolfensis. While primitive, the dentition is generally small and simple in occlusal morphology. H. naledi has humanlike manipulatory adaptations of the hand and wrist. It also exhibits a humanlike foot and lower limb. These humanlike aspects are contrasted in the postcrania with a more primitive or australopith-like trunk, shoulder, pelvis and proximal femur. Representing at least 15 individuals with most skeletal elements repeated multiple times, this is the largest assemblage of a single species of hominins yet discovered in Africa.
The term ‘pseudo-single domain’ (PSD) has been used to describe the transitional state in rock magnetism that spans the particle size range between the single domain (SD) and multi-domain (MD) states. The particle size range for the stable SD state in the most commonly occurring terrestrial magnetic mineral, magnetite, is so narrow (~20-75 nm) that it is widely considered that much of the paleomagnetic record of interest is carried by ‘PSD’ rather than stable SD particles. The PSD concept has, thus, become the dominant explanation for the magnetization associated with a major fraction of particles that record paleomagnetic signals throughout geological time. In this paper, we argue that in contrast to the SD and MD states, the term ‘PSD’ does not describe the relevant physical processes, which have been documented extensively using three-dimensional micromagnetic modeling, and by parallel research in materials science and solid-state physics. We also argue that features attributed to ‘PSD’ behavior can be explained by nucleation of a single magnetic vortex immediately above the maximum stable SD transition size. With increasing particle size, multiple vortices, antivortices, and domain walls can nucleate, which produce variable cancellation of magnetic moments and a gradual transition into the MD state. Thus, while the term ‘PSD’ describes a well-known transitional state, it fails to describe adequately the physics of the relevant processes. We recommend that use of this term should be discontinued in favor of “vortex state”, which spans a range of behaviors associated with magnetic vortices.
where n is the number of magnetic mineral components within a specimen and k corresponds to a log-normal probability density function. From Eq. (2), it is possible to calculate a function that represents the continuous realization of the discrete measured data. Various statistical procedures are used to determine the goodness of fit for a particular model compared to the measured data using either statistical tests (F-test and t-test; Kruiver et al., 2001) or automated iterative approaches (Expectation Algorithm; Heslop et al., 2002). These models are accessible for readers to use through downloads of an excel workbook (IRM-CLG; Kruiver et al., 2001) and a Fortran90 executable program (IRM UnMix, available for PCs; Heslop et al., 2002). Fitting is achieved through either manual entry (Kruiver et al., 2001) or through automated optimization (Heslop et al., 2002).
Although the transition from Australopithecus to Homo is usually thought of as a momentous transformation, the fossil record bearing on the origin and earliest evolution of Homo is virtually undocumented. As a result, the poles of the transition are frequently attached to taxa (e.g. A. afarensis, at ca 3.0 Ma versus H. habilis or H. erectus, at ca 2.0–1.7 Ma) in which substantial adaptive differences have accumulated over significant spans of independent evolution. Such comparisons, in which temporally remote and adaptively divergent species are used to identify a ‘transition’, lend credence to the idea that genera should be conceived at once as monophyletic clades and adaptively unified grades. However, when the problem is recast in terms of lineages, rather than taxa per se , the adaptive criterion becomes a problem of subjectively privileging ‘key’ characteristics from what is typically a stepwise pattern of acquisition of novel characters beginning in the basal representatives of a clade. This is the pattern inferred for species usually included in early Homo , including H. erectus , which has often been cast in the role as earliest humanlike hominin. A fresh look at brain size, hand morphology and earliest technology suggests that a number of key Homo attributes may already be present in generalized species of Australopithecus , and that adaptive distinctions in Homo are simply amplifications or extensions of ancient hominin trends.
This article is part of the themed issue ‘Major transitions in human evolution’.
Haasgat is a primate-rich fossil locality in the northeastern part of the Fossil Hominid Sites of South Africa UNESCO World Heritage Site. Here we report the first hominin identified from Haasgat, a partial maxillary molar (HGT 500), that was recovered from an
ex situ
calcified sediment block sampled from the locality. The
in situ
fossil bearing deposits of the Haasgat paleokarstic deposits are estimated to date to slightly older than 1.95 Ma based on magnetobiostratigraphy. This places the hominin specimen at a critical time period in South Africa that marks the last occurrence of
Australopithecus
around 1.98 Ma and the first evidence of
Paranthropus
and
Homo
in the region between ∼2.0 and 1.8 Ma. A comprehensive morphological evaluation of the Haasgat hominin molar was conducted against the current South African catalogue of hominin dental remains and imaging analyses using micro-CT, electron and confocal microscopy. The preserved occlusal morphology is most similar to
Australopithecus africanus
or early
Homo
specimens but different from
Paranthropus
. Occlusal linear enamel thickness measured from micro-CT scans provides an average of ∼2.0 mm consistent with
Australopithecus
and early
Homo
. Analysis of the enamel microstructure suggests an estimated periodicity of 7–9 days. Hunter–Schreger bands appear long and straight as in some
Paranthropus
, but contrast with this genus in the short shape of the striae of Retzius. Taken together, these data suggests that the maxillary fragment recovered from Haasgat best fits within the
Australopithecus
—early
Homo
hypodigms to the exclusion of the genus
Paranthropus
. At ∼1.95 Ma this specimen would either represent another example of late occurring
Australopithecus
or one of the earliest examples of
Homo
in the region. While the identification of this first hominin specimen from Haasgat is not unexpected given the composition of other South African penecontemporaneous site deposits, it represents one of the few hominin localities in the topographically-distinct northern World Heritage Site. When coupled with the substantial differences in the mammalian faunal communities between the northern localities (e.g., Haasgat, Gondolin) and well-sampled Bloubank Valley sites (e.g., Sterkfontein, Swartkrans, Kromdraai), the recovery of the HGT 500 specimen highlights the potential for further research at the Haasgat locality for understanding the distribution and interactions of hominin populations across the landscape, ecosystems and fossil mammalian communities of early Pleistocene South Africa. Such contextual data from sites like Haasgat is critical for understanding the transition in hominin representation at ∼2 Ma sites in the region from
Australopithecus
to
Paranthropus
and early
Homo
.
The Drimolen Palaeocave System Main Quarry deposits (DMQ) are some of the most prolific hominin and primate-bearing deposits in the Fossil Hominids of South Africa UNESCO World Heritage Site. Discovered in the 1990s, excavations into the DMQ have yielded a demographically diverse sample of
Paranthropus robustus
(including DNH 7, the most complete cranium of the species recovered to date), early
Homo
,
Papio hamadryas robinsoni
and
Cercopithecoides williamsi
. Alongside the hominin and primate sample is a diverse macromammalian assemblage, but prior publications have only provided a provisional species list and an analysis of the carnivores recovered prior to 2008. Here we present the first description and analysis of the non-primate macromammalian faunas from the DMQ, including all 826 taxonomically identifiable specimens catalogued from over two decades of excavation. We also provide a biochronological interpretation of the DMQ deposits and an initial discussion of local palaeoecology based on taxon representation.The current DMQ assemblage consists of the remains of minimally 147 individuals from 9 Orders and 14 Families of mammals. The carnivore assemblage described here is even more diverse than established in prior publications, including the identification of
Megantereon whitei
,
Lycyaenops silberbergi
, and first evidence for the occurrence of
Dinofelis
cf.
barlowi
and
Dinofelis
aff.
piveteaui
within a single South African site deposit. The cetartiodactyl assemblage is dominated by bovids, with the specimen composition unique in the high recovery of horn cores and dominance of
Antidorcas recki
remains. Other cetartiodactyl and perissodactyl taxa are represented by few specimens, as are
Hystrix
and
Procavia
; the latter somewhat surprisingly so given their common occurrence at penecontemporaneous deposits in the region. Equally unusual (particularly given the size of the sample) is the identification of single specimens of giraffoid, elephantid and aardvark (
Orycteropus
cf.
afer
) that are rarely recovered from regional site deposits. Despite the diversity within the DMQ macromammalian faunas, there are few habitat- or biochronologically-sensitive species that provide specific ecologic or age boundaries for the deposits. Recovered species can only support the non-specific, mixed open-to-closed palaeohabitats around Drimolen that have been reconstructed for the other penecontemporaneous South African palaeokarst deposits. The identified
Equus quagga
ssp. specimens recovered from the floor of the current excavation (∾−4.5–5 m below datum) suggests that most, if not all the DMQ specimens, were deposited after 2.33 Ma. Simultaneously, the carnivore specimens (
D.
cf.
barlowi, L. silberbergi
) suggest earlier Pleistocene (pre- 2.0–1.8 Ma) to maximally 1.6 Ma deposition (
D.
aff.
piveteaui
) for most of the DMQ fossil assemblage.
Australopithecus sediba has been hypothesized to be a close relative of the genus Homo. Here
we show that MH1, the type specimen of A. sediba, was not optimized to produce high molar
bite force and appears to have been limited in its ability to consume foods that were
mechanically challenging to eat. Dental microwear data have previously been interpreted as
indicating that A. sediba consumed hard foods, so our findings illustrate that mechanical data
are essential if one aims to reconstruct a relatively complete picture of feeding adaptations in
extinct hominins. An implication of our study is that the key to understanding the origin of
Homo lies in understanding how environmental changes disrupted gracile australopith niches.
Resulting selection pressures led to changes in diet and dietary adaption that set the stage for
the emergence of our genus.
Nearly a century of paleontological excavation and analysis from the cave deposits of the Cradle of Humankind UNESCO World Heritage Site in northeastern South Africa underlies much of our understanding of the evolutionary history of hominins, other primates and other mammal lineages in the late Pliocene and early Pleistocene of Africa. As one of few designated fossil repositories, the Plio-Pleistocene Palaeontology Section of the Ditsong National Museum of Natural History (DNMNH; the former Transvaal Museum) curates much of the mammalian faunas recovered from the fossil-rich deposits of major South African hominin-bearing localities, including the holotype and paratype specimens of many primate, carnivore, and other mammal species (Orders Primates, Carnivora, Artiodactyla, Eulipotyphla, Hyracoidea, Lagomorpha, Perissodactyla, and Proboscidea). Here we describe an open-access digital archive of high-resolution, full-color three-dimensional (3D) surface meshes of all 89 non-hominin holotype, paratype and significant mammalian specimens curated in the Plio-Pleistocene Section vault. Surface meshes were generated using a commercial surface scanner (Artec Spider, Artec Group, Luxembourg), are provided in formats that can be opened in both open-source and commercial software, and can be readily downloaded either via an online data repository (MorphoSource) or via direct request from the DNMNH. In addition to providing surface meshes for each specimen, we also provide tomographic data (both computerized tomography [CT] and microfocus [microCT]) for a subset of these fossil specimens. This archive of the DNMNH Plio-Pleistocene collections represents the first research-quality 3D datasets of African mammal fossils to be made openly available. This simultaneously provides the paleontological community with essential baseline information (e.g., updated listing and 3D record of specimens in their current state of preservation) and serves as a single resource of high-resolution digital data that improves collections accessibility, reduces unnecessary duplication of efforts by researchers, and encourages ongoing imaging-based paleobiological research across a range of South African non-hominin fossil faunas. Because the types, paratypes, and key specimens include globally-distributed mammal taxa, this digital archive not only provides 3D morphological data on taxa fundamental to Neogene and Quaternary South African palaeontology, but also lineages critical to research on African, other Old World, and New World paleocommunities. With such a broader impact of the DNMNH 3D data, we hope that establishing open access to this digital archive will encourage other researchers and institutions to provide similar resources that increase accessibility to paleontological collections and support advanced paleobiological analyses.
A new partial cranium (UW 88-886) of the Plio-Pleistocene baboon Papio angusticeps from Malapa is identified, described and discussed. UW 88-886 represents the only non-hominin primate yet recovered from Malapa and is important both in the context of baboon evolution as well as South African hominin site biochronology. The new specimen may represent the first appearance of modern baboon anatomy and coincides almost perfectly with molecular divergence date estimates for the origin of the modern P. hamadryas radiation. The fact that the Malapa specimen is dated between ~2.026–2.36 million years ago (Ma) also has implications for the biochronology of other South African Plio-Pleistocene sites where P. angusti-ceps is found.
The co-occurrence of Paranthropus robustus and early Homo in South Africa has so far been firmly documented only at the site of Swartkrans. Our analysis of a sample of 79 early hominid fossil specimens from the newly discovered cave site of Drimolen confirms that Paranthropus [Australopithecus] robustus was contemporaneous with early Homo in South Africa during the Plio-Pleistocene. In addition, analysis of the large number of robust australopithecine dental remains from Drimolen demonstrates the considerable variability in this taxon. The sub-sample of deciduous P. robustus teeth from Drimolen encompasses a wide range of the metrical and morphological variation observed in the robust australopithecine samples from Swartkrans and Kromdraai. This finding supports the idea of a single, variable species of robust australopithecine in South Africa during the Plio-Pleistocene. At the same time, it weakens the hypothesis of the existence of two separate robust australopithecine species (namely, P. robustus from the site of Kromdraai and P. crassidens from Swartkrans) in South Africa, as first proposed by Broom and later supported by others.
Our understanding of the origin of the genus Homo has been hampered by a limited fossil record in eastern Africa between 2.0 and 3.0 million years ago (Ma). Here we report the discovery of a partial hominin mandible with teeth from the Ledi-Geraru research area, Afar Regional State, Ethiopia, that establishes the presence of Homo at 2.80-2.75 Ma. This specimen combines primitive traits seen in early Australopithecus with derived morphology observed in later Homo, confirming that dentognathic departures from the australopith pattern occurred early in the Homo lineage. The Ledi-Geraru discovery has implications for hypotheses about the timing and place of the origin of the genus Homo.
Copyright © 2015, American Association for the Advancement of Science.
Besides Homo erectus (sensu lato), the eastern African fossil record of early Homo has been interpreted as representing either a single variable species, Homo habilis, or two species. In the latter case, however, there is no consensus over the respective groupings, and which of the two includes OH 7, the 1.8-million-year-old H. habilis holotype. This partial skull and hand from Olduvai Gorge remains pivotal to evaluating the early evolution of the Homo lineage, and by priority names one or other of the two taxa. However, the distorted preservation of the diagnostically important OH 7 mandible has hindered attempts to compare this specimen with other fossils. Here we present a virtual reconstruction of the OH 7 mandible, and compare it to other early Homo fossils. The reconstructed mandible is remarkably primitive, with a long and narrow dental arcade more similar to Australopithecus afarensis than to the derived parabolic arcades of Homo sapiens or H. erectus. We find that this shape variability is not consistent with a single species of early Homo. Importantly, the jaw morphology of OH 7 is incompatible with fossils assigned to Homo rudolfensis and with the A.L. 666-1 Homo maxilla. The latter is morphologically more derived than OH 7 but 500,000 years older, suggesting that the H. habilis lineage originated before 2.3 million years ago, thus marking deep-rooted species diversity in the genus Homo. We also reconstructed the parietal bones of OH 7 and estimated its endocranial volume. At between 729 and 824 ml it is larger than any previously published value, and emphasizes the near-complete overlap in brain size among species of early Homo. Our results clarify the H. habilis hypodigm, but raise questions about its phylogenetic relationships. Differences between species of early Homo appear to be characterized more by gnathic diversity than by differences in brain size, which was highly variable within all taxa.
High-resolution first-order reversal curve (FORC) diagrams are
increasingly employed to characterize magnetic minerals in sediments,
and especially as a magnetofossil detection tool. Conventional
processing protocols, however, are not well suited for this purpose
because the opposed needs of high resolution and smoothing of noisy data
over different regions of the FORC diagram cannot be reconciled. This
problem is particularly severe in samples containing non-interacting
single-domain particles, whose FORC signature is described by an
infinitely narrow, divergent feature called a central ridge. In this
paper, a new FORC processing protocol called VARIFORC (VARIable FORC
smoothing) is presented for the analysis of non-regular FORC functions,
such as those featuring a central ridge. This protocol is based on
weighted polynomial regression of rectangular arrays of measurement
points whose size is determined by the local properties of the FORC
function (i.e. small arrays where high resolution is needed and
vice-versa). The resulting FORC diagram is characterized by improved
signal-to-noise ratios that pass significance tests over much larger
domains. This enables simultaneous quantitative analysis of FORC
signatures corresponding to different magnetization processes (e.g. the
central ridge produced by single-domain particles and a weak, extended
background due to detrital magnetic minerals). VARIFORC has been
successfully tested on a magnetofossil-bearing pelagic carbonate sample
that has a non-regular FORC function, and on a volcanic ash sample with
a typical pseudo-single-domain signature. An unexpected minor central
ridge contribution, which is invisible to traditional processing, has
been detected in the volcanic ash sample. This finding demonstrates the
effectiveness of the new FORC processing protocol and potential new
applications of high-resolution FORC measurements.
A very limiting factor for paleoanthropological studies is the poor state of preservation of the human fossil record, where fragmentation and deformation are considered normal. Although anatomical information can still be gathered from a distorted fossil, such specimens must typically be excluded from advanced morphological and morphometric analyses, thus reducing the fossil sample size and, ultimately, our knowledge of human evolution. In this contribution we provide the first digital reconstruction of the KNM-ER 1813 Homo habilis cranium. Based on state of-the-art three-dimensional digital modeling and geometric morphometric (GM) methods, the facial portion was aligned to the neurocranium, the overall distortion was removed, and the missing regions were restored. The reconstructed KNM-ER 1813 allows for an adjustment of the anthropometric measurements gathered on the original fossil. It is suitable for further quantitative studies, such as GM analyses focused on skull morphology or for finite element analysis to explore the mechanics of early Homo feeding behavior and diet. Am J Phys Anthropol 153:154-160, 2014. © 2013 Wiley Periodicals, Inc.
The site of Dmanisi, Georgia, has yielded an impressive sample of hominid cranial and postcranial remains, documenting the
presence of Homo outside Africa around 1.8 million years ago. Here we report on a new cranium from Dmanisi (D4500) that, together with its
mandible (D2600), represents the world's first completely preserved adult hominid skull from the early Pleistocene. D4500/D2600
combines a small braincase (546 cubic centimeters) with a large prognathic face and exhibits close morphological affinities
with the earliest known Homo fossils from Africa. The Dmanisi sample, which now comprises five crania, provides direct evidence for wide morphological
variation within and among early Homo paleodemes. This implies the existence of a single evolving lineage of early Homo, with phylogeographic continuity across continents.
The Drimolen Palaeocave System in the ‘Fossil Hominid Sites of South Africa’ UNESCO World Heritage Site is well known for numerous remains of early hominins such as Paranthropus robustus and early Homo. These hominin fossils, along with bone tools and notably diverse accumulation of non-hominin primates and fauna, have all been excavated from the 'Main Quarry' area of the site where extensive lime-mining took place. Here we report the first radiometric age of 1.712 ± 0.269 Ma for hominin bearing deposits associated with the DNH7 Paranthropus robustus cranium in the Main Quarry area of the site, which is consistent with recent biochronological estimates. This age is similar to recent estimates for Swartkrans Member 1 Hanging Remnant (somewhere between 2.3 and 1.8 Ma) which also contains Paranthropus and early Homo. Simultaneously, we integrate the newly radiometrically dated Main Quarry deposits with a new fossil deposit, the Drimolen Makondo, discovered in 2013, that is situated some 50 m up the hill to the west from the Main Quarry. It has experienced only limited disturbance from mining but much more extensive erosion. Preliminary excavations and analysis have revealed that the Makondo infill is older than the Main Quarry, dating to 2.706 ± 0.428 Ma. Its greater age is confirmed by biochronology. The Makondo thus overlap with the suggested end of deposition of Australopithecus bearing Sterkfontein deposits, although it is yet to yield any hominin remains. These new dates for the two Drimolen Palaeocave System deposits indicates that, contrary to prior age estimates, the Drimolen site as a whole records the critical hominin and faunal turnover in South African palaeocommunities that occurred around 2.3–1.7 Ma. Finally, as the Drimolen Makondo represents a rare example of a pre-2 Ma fossil bearing deposit in the Gauteng exposures of the Malmani dolomite, we also integrate our results into the greater South African record of palaeodeposit formation (most of which occur between ∼2.0 and 1.0 Ma). An analysis of the age of palaeocave infillings across the Malmani dolomite suggests that, as is classically the case with karst, the height within the dolomite is broadly correlated to their age, although with some notable exceptions that are likely related to localised geological features. Our analysis also indicates that most caves have undergone some form of secondary karstification related to a younger phase of cave formation, contrasting with models that suggest the cavities all formed at the same time and that infill is related to erosion and the opening up of cave passages. As such, the reason that few pre-2 Ma deposits have been identified in the Gauteng exposures of the Malmani dolomite is probably because these older caves have been eroded away. Identifying such early caves is critical in understanding whether earlier hominins may have once existed in South Africa or if erosion of older deposits (or an absence of speleogenesis at this time) has made such early periods absent from the geological record.
The Sterkfontein Caves is currently the world's richest Australopithecus-bearing site. Included in Sterkfontein's hominin assemblage is StW 573 ('Little Foot'), a near-complete Australopithecus skeleton discovered in Member 2 in the Silberberg Grotto. Because of its importance to the fossil hominin record, the geological age of StW 573 has been the subject of significant debate. Three main hypotheses have been proposed regarding the formation and age of Member 2 and by association StW 573. The first proposes that Member 2 (as originally defined in the type section in the Silberberg Grotto) started to accumulate at around 2.58 Ma and that the unit is contained within the Silberberg Grotto. The second proposes that Member 2 started forming before 3.67 ± 0.16 Ma and that the deposit extends into the Milner Hall and close to the base of the cave system. The third proposes a 'two-stage burial scenario', in which some sediments and StW 573 represent a secondary and mixed-age accumulation reworked from a higher cave. The stratigraphic and sedimentological implications of these hypotheses are tested here through the application of a multiscale investigation of Member 2, with reference to the taphonomy of the StW 573 skeleton. The complete infilling sequence of Member 2 is described across all exposures of the deposit in the Silberberg Grotto and into the Milner Hall. Sediments are generally stratified and conformably deposited in a sequence of silty sands eroded from well-developed lateritic soils on the landscape surface. Voids, clasts and bioclasts are organized consistently across and through Member 2 conforming with the underlying deposit geometry, indicating gradual deposit accretion with no distinct collapse facies evident and only localized intra-unit postdepositional modification. The stratigraphy and sedimentology of Member 2 support a simple single-stage accumulation process of Member 2 and a primary association between the sediments of Member 2 and the StW 573 'Little Foot' skeleton.
Baboons (Papio hamadryas) are among the most successful extant primates, with a minimum of six distinctive forms throughout Sub-Saharan Africa. However, their presence in the fossil record is unclear. Three early fossil taxa are generally recognized, all from South Africa: Papio izodi, Papio robinsoni and Papio angusticeps. Because of their derived appearance, P. angusticeps and P. robinsoni have sometimes been considered subspecies of P. hamadryas and have been used as biochronological markers for the Plio-Pleistocene hominin sites where they are found. We reexamined fossil Papio forms from across Africa with an emphasis on their distinguishing features and distribution. We find that P. robinsoni and P. angusticeps are distinct from each other in several cranial features, but overlap extensively in dental size. Contrary to previous assessments, no diagnostic cranio-mandibular material suggests these two forms co-occur, and dental variation at each site is comparable to that within P. h. ursinus, suggesting that only one form is present in each case. P izodi, however, may co-occur with P. robinsoni, or another Papio form, at Sterkfontein Member 4. P izodi appears more primitive than P. robinsoni and P. angusticeps. P. robinsoni is slightly distinct from P. hamadryas subspecies in its combination of features while P. angusticeps might be included within one of the modern P. hamadryas varieties (i.e., P. h. angusticeps). No definitive Papio fossils are currently documented in eastern Africa until the Middle Pleistocene, pointing to southern Africa as the geographic place of origin for the genus. These results have implications for Plio-Pleistocene biochronology and baboon evolution.
South Africa contains a wealth of palaeokarst deposits that have yielded hominin fossils and Early Stone Age archaeology. Despite the complex nature of deposition within many of these caves there has been a dearth of detailed geoarchaeological studies undertaken on these sites. Many sites in South Africa have been interpreted using an overly simplistic Member System based on simplified sedimentological attributes, rather than chronostratigrahic units. Many of the defined Members thus identify different, but contemporary geological processes occurring in the caves. This has caused serious confusion in reconstructing the life histories of palaeocaves and the ages of the fossil remains interned within them. It is critical to uncover new sites that have not been extensively altered by decades of data collection and destructive mining techniques employed early in their discovery. Although unmined sites present their own problems with regards to extensive colluvium cover and access to fossil-bearing units, analysing strata that is found in-situ enhances overall confidence of interpretations drawn. A wealth of geoarchaeological and 3D visualisation techniques can now be employed to aid in the understanding of cave life histories, as well as their excavation. In this paper we present the first attempt to integrate and publish data from a range of such methods on South African fossil bearing palaeokarst using the newly discovered Drimolen Makondo deposit as a case study. This includes the use of ground penetrating radar, 3D visualisation through photogrammetry and multi-scale 3D scanning, micromophology and petrography, palaeomagnetism, mineral magnetism, synchrotron radiation, electron spin resonance, uranium-lead dating and biochronology. Our analysis has allowed us to successfully uncover the full extent of this new ∼2.61 Ma fossil bearing palaeokarst deposit and to visualise and interpret its chronostratigraphy.
The brain is a highly plastic organ and is shaped not only during prenatal but also during postnatal development. The analysis and comparison of ontogenetic patterns of endocranial size increase and endocranial shape changes can therefore add further evidence for the interpretation of hominin brain evolution. Here we focus on digital endocast data and the methodology used to document and compare developmental patterns of endocranial shape changes. We outline how geometric morphometrics of endocranial landmark data can be used in an evo-devo approach to human brain evolution, discuss how developmental simulations help to compare ontogenetic patterns among species, present different visualization techniques that help to interpret ontogenetic shape changes, provide an overview of our current knowledge, present new data on early postnatal shape changes in apes, and discuss open questions.
This study presents MCDoseE 2.0, a new fitting program for ESR dating dose response curve (DRC) fitting and dose calculation. The standalone software was specifically designed to remove assumed data weighting, and instead to obtain a full probabilistic solution of the DRC by propagating the uncertainties associated with the measured ESR intensities. It uses a non-linear Bayesian framework, specifically a Markov Chain Monte Carlo (MCMC) scheme based on the Metropolis-Hastings algorithm, where the solution is a probability distribution for the equivalent dose, according to the precision of the measurements. In this paper, we investigate the capabilities and limitations of MCDoseE 2.0 by comparing our results to those obtained with OriginPro 9.1®, a proven and commonly used commercial software package. The two programs were evaluated against both known-dose samples and random archaeological tooth enamel and quartz samples, using three commonly used DRC fitting functions. We found that both programs provide highly consistent results. When comparing the dose estimates obtained by both programs we found that 90% of the solutions are statistically indistinguishable regardless of the data weighting assumption used in OriginPro. We also found that MCDoseE 2.0 offers an increased precision on the ending results compared to the commercial software, as long as each measured ESR uncertainty remains within 2-sigma range of the mean error value of all measured ESR uncertainties of the dataset. The accuracy of the fitting results given by MCDoseE 2.0 are undeniably dependent on the measurement accuracy, and emphasises the need of a proper assessment of the experimental errors in the ESR intensities. A copy of the program is available in Supplementary information, and some basic instructions for its use are provided, as well as recommendations to ensure reliable and accurate fitting results.
Small-volume rhyolitic eruptions preceding and following a caldera-forming eruption can provide insights into the tempo of eruption cycles and timing of magmatic recharge. In this contribution, high-precision ⁴⁰Ar/³⁹Ar eruption ages were obtained on the three effusive eruptions bracketing the Huckleberry Ridge Tuff, which comprise Yellowstone's first volcanic cycle. These dates are supplemented with detailed paleomagnetic and rock magnetic analyses to resolve discrepancies with previous reported stratigraphy. The Huckleberry Ridge Tuff (2.08 Ma) was preceded by an eruption at 2.14 Ma, and followed by eruptions at 1.98 and 1.95 Ma, all of which occurred during four distinct periods of geomagnetic instability within the Matuyama chron. The first volcanic cycle of Yellowstone has now been constrained to within a 200 kyr timespan, or half of the previously proposed duration, and similar to the duration of volcanic activity for caldera-forming systems in the Jemez Volcanic Field. The maximum duration for magmatic recharge for the first Yellowstone volcanic cycle is no greater than 100 kyr, and likely closer to 40 kyr. Furthermore, the combined ⁴⁰Ar/³⁹Ar eruption ages and paleomagnetic results provide polarity anchors for the Pre-Olduvai excursion and Olduvai subchron, which are often used as tie-points in studies of early Pleistocene hominin evolution.
Malapa Hominin (MH) 1, an immature individual whose second permanent molars had recently reached occlusion at the time of death, is the holotype of Australopithecus sediba, a 2-myr-old South African taxon that has been hypothesized to link phylogenetically australopith-grade hominins to the Homo clade. Given the existence of 2.8 myr-old fossils of Homo in eastern Africa, this hypothesis implies a ghost lineage spanning at least 800 kyr. An alternative hypothesis posits a unique relationship between A. sediba and Australopithecus africanus, which predates the Malapa hominins in southern Africa and whose phylogenetic relationships remain ambiguous. The craniofacial morphology of MH 1 looms large in the framing of the two hypotheses. We evaluated these alternatives in two ways. First, we investigated whether the craniofacial morphology of MH 1 was ontogenetically stable at death. Based on data from a late-growth series of chimpanzee, gorilla, and modern human crania, we found that key aspects of MH 1's resemblance to Homo can be accounted for by its immaturity. Second, we studied MH 1 with an eye to identifying craniofacial synapomorphies shared with A. africanus. In this case, MH 1 shows unambiguous affinities in its zygomaticomaxillary and supraorbital morphology to crania from Sterkfontein Member 4, which we found to exhibit unusual derived morphology compared to Homo and other australopiths. We argue that MH 1 provides clear evidence that A. sediba was uniquely related to A. africanus and that the hypothesis of an extensive ghost lineage connecting A. sediba to the root of the Homo clade is unwarranted.
I report on a well-preserved Paranthropus robustus skull and another mandible from the recently discovered dolomitic cave site of Drimolen, Krugersdorp District, South Africa. The skull (DNH 7), a presumed female, consists of the first cranium and articulated mandible with the most complete dentition yet described for this taxon. Found juxtaposed to the skull was a large and presumably male mandible, with almost complete dentition (DNH 8). Paranthropus robustus was described from Kromdraai in South Africa in 1938 and in 1948 from Swartkrans, and has until recently been definitively known only from these two sites. Owing to the distortion of many of the Swartkrans crania, it has been suggested that P. robustus displays a smaller degree of intraspecific variability than the better preserved specimens of Paranthropus boisei from East Africa. Owing to the excellent preservation of this new skull, it is now possible to demonstrate that P. robustus shows a greater degree of intraspecific variability in both morphology and size, indicating greater sexual dimorphism in this species, than was previously thought.
ELECTRON SPIN RESONANCE (ESR) DATING offers the potential to provide dates for Plio-Pleistocene sites in South Africa. Previous attempts have been made to date tooth enamel samples from Sterkfontein, Swartkrans and Gladysvale. Here we report results of ESR dating of tooth enamel from Kromdraai B in the Sterkfontein Valley.
Brain Endocasts is the only comprehensive, single-volume work dealing exclusively and uniformly with fossil hominid brain endocasts. Never-before-published photographs come together with easily accessible, coherent descriptions to create a detailed reference on the paleoneurological evidence for human evolution. Each entry offers essential information related to the location, dating, associations, and morphology of a given endocast. The text also covers the latest methodologies and techniques available for studying endocasts. In addition, a concise summary shows how these fossil records contribute to our understanding of human evolution and behavior.
Bovidae contain the cattle, sheep, goats, and antelopes. The word “antelope” is used for bovids outside Europe, mostly in Africa, or not domesticated before Carl Linnaeus' lifetime. It does not correspond with a formal taxonomic category. Most phylogenies postulate bovids being closer to cervids than to giraffids. Unlike the cervoid Moschus in relation to Cervidae, there is no living hornless pecoran thought to be a bovoid (member of a superfamily Bovoidea including Bovidae and any related families, the latter as yet unknown). In Eurasia, tiny bovid-like dental remains are known well back to the early Oligocene of Mongolia, but nothing is known of pre-Miocene ruminants in Africa. Pecorans such as Walangania, Propalaeoryx, and Namibiomeryx do appear in the early Miocene, and the last has been claimed to be a bovid. Subfamilies of Bovidae include Hypsodontinae, Bovinae, Antilopinae, Reduncinae, Oiocerinae, Hippotraginae, and Caprinae. This chapter discusses the overall classification of Bovidae and their evolutionary relationships.
Six tuffaceous beds within the Omo Group of the Omo–Turkana Basin have been dated using the ⁴⁰ Ar/ ³⁹ Ar single crystal total fusion method on anorthoclase, yielding eruption ages. The Omo Group constitutes up to 800 m of subaerially exposed sediments surrounding Lake Turkana within the East African Rift system in northern Kenya and southern Ethiopia. Rhyolitic explosive eruptions produced tuffs and pumice clasts that are considered to have been deposited shortly after eruption. The new age data on feldspars from the pumice clasts range from 4.02 ± 0.04 Ma for the Naibar Tuff of the Koobi Fora Formation to 1.53 ± 0.02 Ma for Tuff K of the Shungura Formation. The Orange Tuff in the KBS Member of the Koobi Fora Formation was dated at 1.76 ± 0.03 Ma, providing good control in this part of the sequence where formerly there was a >200 ka gap. Data are consistent with earlier measurements and significantly improve age resolution within the Omo Group, which has yielded many vertebrate fossils, including hominin fossils comprising a number of species. We suggest new age estimates for a limited number of hominin specimens.
Supplementary material
Eleven tables and nine figures are available at www.geolsoc.org.uk/SUP18506 .
Combined ESR/U-series dating of tooth enamel using US model implies the calculation of a specific parameter p for each dental tissue to reconstruct its U-uptake history. The US model simulates this history as a continuous incorporation process without leaching, where the 238U–234U–230Th system evolves towards secular equilibrium state. Consequently, the application of this model is restricted to the samples displaying 230Th/234U activity ratio below or close to equilibrium with maximum value of ∼1.05 for each tissue. In order to overcome this limitation, here, a new model named Accelerating Uptake (AU) model is proposed. This model describes U-uptake into dental tissue as an accelerating process by the introduction of two parameters, the initial uptake rate and the acceleration of this uptake rate. The AU model is then able to reconstruct a process combining incorporation followed by leaching, as well as continuous uptake one. With this model, the evolution of 230Th/234U activity ratio with time can reach values higher than unity, even beyond equilibrium. The AU model is useful in cases for which age estimates cannot be calculated by routine use of US model. The application of the AU model to the palaeoanthropological site of Mauer in Germany shows its potential for extending the applicability of the combined ESR/U-series dating of tooth enamel.