First Early Hominin from Central Africa (Ishango,Democratic Republic of Congo)

Despite uncontested evidence for fossils belonging to the early hominin genus Australopithecus in East Africa from at least 4.2 million years ago (Ma), and from Chad by 3.5 Ma, thus far there has been no convincing evidence of Australopithecus, Paranthropus or early Homo from the western (Albertine) branch of the Rift Valley. Here we report the discovery of an isolated upper molar (#Ish25) from the Western Rift Valley site of Ishango in Central Africa in a derived context, overlying beds dated to between ca. 2.6 to 2.0 Ma. We used µCT imaging to compare its external and internal macro-morphology to upper molars of australopiths, and fossil and recent Homo. We show that the size and shape of the enamel-dentine junction (EDJ) surface discriminate between Plio-Pleistocene and post-Lower Pleistocene hominins, and that the Ishango molar clusters with australopiths and early Homo from East and southern Africa. A reassessment of the archaeological context of the specimen is consistent with the morphological evidence and suggest that early hominins were occupying this region by at least 2 Ma.     

Stretching the time span of hominin evolution at Kromdraai (Gauteng,South Africa): Recent discoveries

The Plio-Pleistocene locality of Kromdraai B has yielded the type specimen of Paranthropus robustus, as well as 27 additional fossil hominin specimens. In a number of both cranial and dental features, the states shown by the Kromdraai Paranthropus are more conservative when compared to the more derived conditions displayed by both South African conspecifics and the post-2.3 Ma eastern African Paranthropus boisei. Since 2014, we excavated the earliest known infilling of the Kromdraai cave system in a previously unexplored area. This new locality provided as yet 2200 identifiable macrovertebrate fossils, including 22 hominins, all tied in the earliest part of the stratigraphic sequence, representing three distinct depositional periods. Since we report here, for the first time, the occurrence of fossil hominins in Members 1 and 2, our discoveries stretch the time span of hominin evolution at Kromdraai and contribute to a better understanding of the origin of Paranthropus in southern Africa.     

Recent paleoanthropological excavations of in situ deposits at Makapansgat, South Africa--a first report

The Makapansgat Limeworks is a significant Pliocene site both for its sample of 35 hominin fossils as well as its wealth of fossil fauna. The lithological and paleontological successions reveal local environmental changes that are important for understanding the context of hominin evolution in southern Africa. Yet most of the site's fossils were found in dumps left behind by quarry operations, and the paleoecological interpretations rest upon debatable assumptions about the original fossil provenience. We have recently initiated systematic paleoanthropological excavations at Makapansgat to recover well provenanced fossils in order to: 1) assess whether faunal successions are discernable in the Makapansgat sequence; 2) assist environmental interpretations of the site; 3) and potentially recover the oldest hominins in South Africa, roughly coincident with Australopithecus afarensis in East Africa. This paper presents a summary of our current paleoenvironmental research at the Limeworks and preliminary results of ongoing in situ excavations.     

Dental Ontogeny in Pliocene and Early Pleistocene Hominins

Until recently, our understanding of the evolution of human growth and development derived from studies of fossil juveniles that employed extant populations for both age determination and comparison. This circular approach has led to considerable debate about the human-like and ape-like affinities of fossil hominins. Teeth are invaluable for understanding maturation as age at death can be directly assessed from dental microstructure, and dental development has been shown to correlate with life history across primates broadly. We employ non-destructive synchrotron imaging to characterize incremental development, molar emergence, and age at death in more than 20 Australopithecus anamensis, Australopithecus africanus, Paranthropus robustus and South African early Homo juveniles. Long-period line periodicities range from at least 6–12 days (possibly 5–13 days), and do not support the hypothesis that australopiths have lower mean values than extant or fossil Homo. Crown formation times of australopith and early Homo postcanine teeth fall below or at the low end of extant human values; Paranthropus robustus dentitions have the shortest formation times. Pliocene and early Pleistocene hominins show remarkable variation, and previous reports of age at death that employ a narrow range of estimated long-period line periodicities, cuspal enamel thicknesses, or initiation ages are likely to be in error. New chronological ages for SK 62 and StW 151 are several months younger than previous histological estimates, while Sts 24 is more than one year older. Extant human standards overestimate age at death in hominins predating Homo sapiens, and should not be applied to other fossil taxa. We urge caution when inferring life history as aspects of dental development in Pliocene and early Pleistocene fossils are distinct from modern humans and African apes, and recent work has challenged the predictive power of primate-wide associations between hominoid first molar emergence and certain life history variables.     

Sr/Ca and early hominin diets revisited: new data from modern and fossil tooth enamel

A previous study of strontium/calcium (Sr/Ca) ratios in Paranthropus suggested that it consumed more animal foods than was previously believed. However, that study looked at Sr/Ca in fossil bone, which is known to be highly susceptible to diagenesis. Enamel, in contrast, is resistant to post-mortem alteration making it a more appropriate material for Sr/Ca analysis of Plio-Pleistocene fossils. Yet, we know virtually nothing about Sr/Ca in the enamel of modern African mammals, much less fossil taxa. To address this gap, we studied Sr/Ca in tooth enamel from modern mammals in the greater Kruger National Park, South Africa, as well as fossil fauna from the Sterkfontein Valley. Grazing herbivores have the highest Sr/Ca, followed by browsers and carnivores in both modern and fossil fauna. This similarity in ecological Sr/Ca patterning between modern and fossil fauna shows that diagenesis has not obscured the primary dietary signals. Australopithecus has significantly higher Sr/Ca than Paranthropus, and higher Sr/Ca than fossil papionins, browsers, and carnivores. Paranthropus has lower Sr/Ca than grazers, but its Sr/Ca is higher or equal to that of fossil papionins, browsers, and carnivores. Thus, Sr/Ca for both hominins is relatively high, and provides no direct evidence for omnivory in either taxon. The consumption of underground resources or insects are among the possible explanations for the highly elevated Sr/Ca in Australopithecus.     

Surface Model and Tomographic Archive of Fossil Primate and Other Mammal Holotype and Paratype Specimens of the Ditsong National Museum of Natural History,Pretoria, South Africa

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.     

中更新世晚期中国古人类化石的形态多样性及其演化意义

近年对许家窑、许昌、华龙洞、澎湖、夏河、哈尔滨等人类化石开展的系统研究,引发了学界对中更新世晚期人类演化及分类的不同认识。基于对相关中国人类化石形态特征的分析,作者提出这一时期中国人类化石形态特征表现为四种类型：1）以中更新世晚期人类共有特征为主;2）以原始特征为主;3）以现代特征为主;4）独特形态组合。多数化石形态特征表现为前三种类型,而许昌和许家窑这种以硕大的头骨和巨大颅容量构成的独特形态组合在其他同时期化石还没有发现。化石形态的多样性提示,不同类型的中更新世晚期中国古人类对现代人的形成贡献不同。作者认为在该时期的人类化石形态多样性规律还未阐明的情况下,将具有混合或镶嵌特征的相关人类化石归入分类地位不确定的人群较为合适。     

Evidence in hand: recent discoveries and the early evolution of human manual manipulation

For several decades, it was largely assumed that stone tool use and production were abilities limited to the genus Homo. However, growing palaeontological and archaeological evidence, comparative extant primate studies, as well as results from methodological advancements in biomechanics and morphological analyses, have been gradually accumulating and now provide strong support for more advanced manual manipulative abilities and tool-related behaviours in pre-Homo hominins than has been traditionally recognized. Here, I review the fossil evidence related to early hominin dexterity, including the recent discoveries of relatively complete early hominin hand skeletons, and new methodologies that are providing a more holistic interpretation of hand function, and insight into how our early ancestors may have balanced the functional requirements of both arboreal locomotion and tool-related behaviours.     

Homogeneity of fossil assemblages extracted from mine dumps: an analysis of Plio-Pleistocene fauna from South African caves

Mine dumps associated with limestone cave deposits are common in dolomitic areas of southern Africa. The dumps often contain blocks of breccia, which are rich in micro-mammalian fossils (especially rodents, shrews and bats). Unfortunately, these fossiliferous breccia blocks are out of geological and stratigraphic context. Nevertheless, they provide a large amount of palaeontological material of great interest. In order to use this kind of material, a first approach is to test for homogeneity of the fossil assemblages extracted from the breccia blocks. Fisher's exact test can be used. Two analyses were undertaken. The first was performed on block samples taken in situ from breccia at the Drimolen hominid site. The results indicated that the samples were homogenous, as expected. The second analysis was carried out on different samples extracted from blocks of breccia collected from a dump at the Gondolin site. The results show that it is possible to group several samples in a single representative assemblage. Some blocks could be grouped together and then used to address taphonomic issues. Once these problems are solved, the data set can be used with greater confidence to address matters concerning palaeoenvironmental reconstructions associated with Plio-Pleistocene hominids.     

Brief communication: enamel thickness trends in the dental arcade of humans and chimpanzees

In addition to evidence for bipedality in some fossil taxa, molar enamel thickness is among the few characters distinguishing (thick-enameled) hominins from the (thin-enameled) African apes. Despite the importance of enamel thickness in taxonomic discussions and a long history of scholarship, measurements of enamel thickness are performed almost exclusively on molars, with relatively few studies examining premolars and anterior teeth. This focus on molars has limited the scope of enamel thickness studies (i.e., there exist many fossil hominin incisors, canines, and premolars). Increasing the available sample of teeth from which to compare enamel thickness measurements from the fossil record could substantially increase our understanding of this aspect of dental biology, and perhaps facilitate greater taxonomic resolution of early hominin fossils. In this study, we report absolute and relative (size-scaled) enamel thickness measurements for the complete dentition of modern humans and chimpanzees. In accord with previous studies of molars, chimpanzees show lower relative enamel thickness at each tooth position, with little overlap between the two taxa. A significant trend of increasing enamel thickness from anterior to posterior teeth is apparent in both humans and chimpanzees, indicating that inter-taxon comparisons should be limited to the same tooth position in order to compare homologous structures. As nondestructive imaging techniques become commonplace (facilitating the examination of increasing numbers of fossil specimens), studies may maximize available samples by expanding beyond molars.     

Postcranial remains and the origin of modern humans

The nature, timing, and location of the origin of modern humans has been the subject of intense controversy for the last 15 years.^1–4 Genetic data and new radiometric dates for key fossils that lie beyond the range of radiocarbon dating have substantially added to the knowledge derived from the fossil evidence documenting the transition from archaic to modern humans. These new data, however, have failed to resolve the problem in its entirety. Most authorities now accept that Africa played an important, and probably central, role in the origin of modern humans.^7–13 The genetic evidence seems to be particularly emphatic that an African population that existed between 200,000 and 100,000 years ago (100 ka) is ancestral to all living humans.^6,7 Controversy still surrounds the question of how much, if at all, archaic humans from outside of Africa, such as Neandertals, late archaic Chinese hominins such as Jinniushan, and the Indonesian Ngandong hominins, may have contributed to the morphological and genetic diversity present in living populations and the morphology of the earliest fossils of modern humans.¹⁰     

Vibrational spectroscopy of fossils

Over the last two decades, there has an been increasing interest in applying vibrational spectroscopy in palaeontological research. For example, this chemical analytical technique has been used to elucidate the chemical composition of a wide variety of fossils, including Archaean putative microfossils, stromatolites, chitinozoans, acritarchs, fossil algae, fossil plant cuticles, putative fossil arthropods, conodonts, scolecodonts and dinosaur bones. The insights provided by these data have been equally far ranging: to taxonomically identify a fossil, to determine biogenicity of a putative fossil, to identify preserved biologically synthesized compounds and to elucidate the preservational mechanisms of fossil material. Vibrational spectroscopy has clearly been a useful tool for investigating various palaeontological problems. However, it is also a tool that has been misapplied and misinterpreted, and thus, this review is dedicated to providing a palaeontologist who is new to vibrational spectroscopy with a basic understanding of these techniques, and the types of chemical information that can be obtained. Two example applications of these techniques are discussed in detail, one looking into fossil palynomorph taxonomy and other into the enigmatic Burgess Shale‐type preservation.     

贵州交榜留茶坡组化石组合特征及其生物地层学和演化意义*

埃迪卡拉纪—寒武纪之交见证了地球—生命系统不同圈层的重大变革, 是复杂多细胞生物演化的重要转折期。华南是开展相关研究的主要区域之一, 但前人工作主要集中在化石材料丰富的浅水台地相区, 深水区生物组成面貌尚未得到充分认识。本研究对斜坡相区贵州交榜剖面的留茶坡组进行了详细研究, 通过酸蚀和薄片观察发现了丰富的化石材料, 包括: 海绵骨针、软舌螺、可能的原牙形类(? Protohertzina sp.)和织金钉类(? Zhijinites sp.)、球形疑源类、Megathrix longus, 及不同类型的多细胞藻类, 亲缘关系未定的Poratusiramus sp.、球形化石和形态多样的丝状、片状化石等。该化石组合属于寒武纪纽芬兰世幸运期, 其中的骨骼化石以海绵骨针为主。化石组合中既有与浅水区共有分子, 也有深水区特有类群, 丰富了斜坡相区的化石记录, 具有潜在的地层对比和演化意义。     

From action to language: comparative perspectives on primate tool use, gesture and the evolution of human language

The papers in this Special Issue examine tool use and manual gestures in primates as a window on the evolution of the human capacity for language. Neurophysiological research has supported the hypothesis of a close association between some aspects of human action organization and of language representation, in both phonology and semantics. Tool use provides an excellent experimental context to investigate analogies between action organization and linguistic syntax. Contributors report and contextualize experimental evidence from monkeys, great apes, humans and fossil hominins, and consider the nature and the extent of overlaps between the neural representations of tool use, manual gestures and linguistic processes.     

Hydrodynamics and sliding posture analysis of the Cambrian arthropod Ercaicunia multinodosa

Dynamic mechanical analysis offers the opportunity to explore the motility and feeding strategies of extinct organisms, but the prerequisite is to have an accurate recovery engineering model. As shown with micro-computed tomography (CT) scanning, fossils of the bivalved arthropod Ercaicunia multinodosa from the Cambrian (Series 2, Stage 3) Chengjiang biota of China have well-preserved three-dimensional (3D) morphological details with a certain degree of compression. Here, we propose a palaeontological restoration method using computational fluid dynamics (CFD) to analyse multiple hypothetical models based on the fossil information to obtain a reasonable restoration model. Furthermore, we carry out hydrodynamic experiments to verify the palaeontological restoration results. Our simulation and experimental results suggest that, a dorsally convex and ventrally straight body shape with the valves opening at an angle of approximately 120° works best for E. multinodosa to overcome resistance, and in the meantime obtain most lift while sliding in the water column. The combination of three-dimensional reconstruction, CFD simulation, and hydrodynamic experiments provides a useful method for restoring the morphologies of extinct animals and exploring their palaeoecology.     

Digital Tools for the Preservation of the Human Fossil Heritage: Ceprano, Saccopastore, and Other Case Studies

Computed tomography is presently one of the most powerful analytical tools available to investigate anatomy and morphology in palaeontological contexts. Apart from its important scientific implications, computed tomography must also be viewed as a tool to analyse the conditions of preservation of fossil remains, to plan restoration processes, and to consider fossils in terms of cultural heritage. A densitometric analysis is necessary in order to check the different geological components, the presence of infiltrations within the fossil volume, as well as the extension and presence of fractures and/or weakened surfaces. Furthermore, biomedical imaging allows non-invasive procedures of reconstruction and reproduction of the original morphology of the specimens. Digital anthropology must also be considered in view of the deontological problems associated with fossil record management and with the diffusion of science.     

Where to Dig for Fossils: Combining Climate-Envelope,Taphonomy and Discovery Models

Fossils represent invaluable data to reconstruct the past history of life, yet fossil-rich sites are often rare and difficult to find. The traditional fossil-hunting approach focuses on small areas and has not yet taken advantage of modelling techniques commonly used in ecology to account for an organism’s past distributions. We propose a new method to assist finding fossils at continental scales based on modelling the past distribution of species, the geological suitability of fossil preservation and the likelihood of fossil discovery in the field, and apply it to several genera of Australian megafauna that went extinct in the Late Quaternary. Our models predicted higher fossil potentials for independent sites than for randomly selected locations (mean Kolmogorov-Smirnov statistic = 0.66). We demonstrate the utility of accounting for the distribution history of fossil taxa when trying to find the most suitable areas to look for fossils. For some genera, the probability of finding fossils based on simple climate-envelope models was higher than the probability based on models incorporating current conditions associated with fossil preservation and discovery as predictors. However, combining the outputs from climate-envelope, preservation, and discovery models resulted in the most accurate predictions of potential fossil sites at a continental scale. We proposed potential areas to discover new fossils of Diprotodon, Zygomaturus, Protemnodon, Thylacoleo, and Genyornis, and provide guidelines on how to apply our approach to assist fossil hunting in other continents and geological settings.     

High-resolution computed tomography for the comparative study of fossil and extant bone

Special methods have been developed to use computed tomography (CT) for 3-dimensional imaging of both fossil and extant bones. Most commercial CT scanners cannot display the internal structure of fossils because the very high density is beyond the upper limits of the normal CT number scale (Hounsfield scale) of the scanners. X-ray projections from CT scans of fossils were modified by scaling the data to provide an expanded CT number scale, allowing the internal structure of highly fossilized objects to be visualized. These images were compared with state-of-the-art, high-resolution CT images of extant bone. Special image reformatting software was used to provide qualitative and quantitative 3-dimensional imaging. The recent rapid advances in CT technology have made this imaging modality the procedure of choice in much of diagnostic radiology. Use of this tool in paleoanthropology has been limited in the past by restricted access to scanners. However, new developments in CT will make this technique available to many researchers in the near future.