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Fossils and artifacts from Herto, Ethiopia, include the most complete child and adult crania of early Homo sapiens . The endocranial cavities of the Herto individuals show that by 160,000 y ago, brain size, inferred from endocranial size, was similar to that seen in modern human populations. However, endocranial shape differed from ours. This gave rise to the hypothesis that the brain itself evolved substantially during the past ∼200,000 y, possibly in tandem with the transition from Middle to Upper Paleolithic techno-cultures. However, it remains unclear whether evolutionary changes in endocranial shape mostly reflect changes in brain morphology rather than changes related to interaction with maxillofacial morphology. To discriminate between these effects, we make use of the ontogenetic fact that brain growth nearly ceases by the time the first permanent molars fully erupt, but the face and cranial base continue to grow until adulthood. Here we use morphometric data derived from digitally restored immature and adult H. sapiens fossils from Herto, Qafzeh, and Skhul (HQS) to track endocranial development in early H. sapiens . Until the completion of brain growth, endocasts of HQS children were similar in shape to those of modern human children. The similarly shaped endocasts of fossil and modern children indicate that our brains did not evolve substantially over the past 200,000 y. Differences between the endocranial shapes of modern and fossil H. sapiens adults developed only with continuing facial and basicranial growth, possibly reflecting substantial differences in masticatory and/or respiratory function.

Body and canine size dimorphism in fossils inform sociobehavioral hypotheses on human evolution and have been of interest since Darwin's famous reflections on the subject. Here, we assemble a large dataset of fossil canines of the human clade, including all available Ardipithecus ramidus fossils recovered from the Middle Awash and Gona research areas in Ethiopia, and systematically examine canine dimorphism through evolutionary time. In particular, we apply a Bayesian probabilistic method that reduces bias when estimating weak and moderate levels of dimorphism. Our results show that Ar. ramidus canine dimorphism was significantly weaker than in the bonobo, the least dimorphic and behaviorally least aggressive among extant great apes. Average male-to-female size ratios of the canine in Ar. ramidus are estimated as 1.06 and 1.13 in the upper and lower canines, respectively, within modern human population ranges of variation. The slightly greater magnitude of canine size dimorphism in the lower than in the upper canines of Ar. ramidus appears to be shared with early Australopithecus, suggesting that male canine reduction was initially more advanced in the behaviorally important upper canine. The available fossil evidence suggests a drastic size reduction of the male canine prior to Ar. ramidus and the earliest known members of the human clade, with little change in canine dimorphism levels thereafter. This evolutionary pattern indicates a profound behavioral shift associated with comparatively weak levels of male aggression early in human evolution, a pattern that was subsequently shared by Australopithecus and Homo.

Body and canine size dimorphism in fossils inform sociobehavioral hypotheses on human evolution and have been of interest since Darwin’s famous reflections on the subject. Here, we assemble a large dataset of fossil canines of the human clade, including all available Ardipithecus ramidus fossils recovered from the Middle Awash and Gona research areas in Ethiopia, and systematically examine canine dimorphism through evolutionary time. In particular, we apply a Bayesian probabilistic method that reduces bias when estimating weak and moderate levels of dimorphism. Our results show that Ar. ramidus canine dimorphism was significantly weaker than in the bonobo, the least dimorphic and behaviorally least aggressive among extant great apes. Average male-to-female size ratios of the canine in Ar. ramidus are estimated as 1.06 and 1.13 in the upper and lower canines, respectively, within modern human population ranges of variation. The slightly greater magnitude of canine size dimorphism in the lower than in the upper canines of Ar. ramidus appears to be shared with early Australopithecus, suggesting that male canine reduction was initially more advanced in the behaviorally important upper canine. The available fossil evidence suggests a drastic size reduction of the male canine prior to Ar. ramidus and the earliest known members of the human clade, with little change in canine dimorphism levels thereafter. This evolutionary pattern indicates a profound behavioral shift associated with comparatively weak levels of male aggression early in human evolution, a pattern that was subsequently shared by Australopithecus and Homo.

In the past decade, the early Acheulean before 1 Mya has been a focus of active research. Acheulean lithic assemblages have been shown to extend back to ∼1.75 Mya, and considerable advances in core reduction technologies are seen by 1.5 to 1.4 Mya. Here we report a bifacially flaked bone fragment (maximum dimension ∼13 cm) of a hippopotamus femur from the ∼1.4 Mya sediments of the Konso Formation in southern Ethiopia. The large number of flake scars and their distribution pattern, together with the high frequency of cone fractures, indicate anthropogenic flaking into handaxe-like form. Use-wear analyses show quasi-continuous alternate microflake scars, wear polish, edge rounding, and striae patches along an ∼5-cm-long edge toward the handaxe tip. The striae run predominantly oblique to the edge, with some perpendicular, on both the cortical and inner faces. The combined evidence is consistent with the use of this bone artifact in longitudinal motions, such as in cutting and/or sawing. This bone handaxe is the oldest known extensively flaked example from the Early Pleistocene. Despite scarcity of well-shaped bone tools, its presence at Konso shows that sophisticated flaking was practiced by ∼1.4 Mya, not only on a range of lithic materials, but also occasionally on bone, thus expanding the documented technological repertoire of African Early Pleistocene Homo.

The evolution of bipedalism in the hominin lineage has shaped the posterior human calcaneus into a large, robust structure considered to be adaptive for dissipating peak compressive forces and energy during heel-strike. A unique anatomy thought to contribute to the human calcaneus and its function is the lateral plantar process (LPP). While it has long been known that humans possess a plantarly positioned LPP and apes possess a more dorsally positioned homologous structure, the relative position of the LPP and intraspecific variation of this structure have never been quantified. Here, we present a method for quantifying relative LPP position and find that, while variable, humans have a significantly more plantar position of the LPP than that found in the apes. Among extinct hominins, while the position of the LPP in Australopithecus afarensis falls within the human distribution, the LPP is more dorsally positioned in Australopithecus sediba and barely within the modern human range of variation. Results from a resampling procedure suggest that these differences can reflect either individual variation of a foot structure/function largely shared among Australopithecus species, or functionally distinct morphologies that reflect locomotor diversity in Plio-Pleistocene hominins. An implication of the latter possibility is that calcaneal changes adaptive for heel-striking bipedalism may have evolved independently in two different hominin lineages.

The dispersal of modern humans from Africa is now well documented with genetic data that track population history, as well as gene flow between populations. Phenetic skeletal data, such as cranial and pelvic morphologies, also exhibit a dispersal-from-Africa signal, which, however, tends to be blurred by the effects of local adaptation and in vivo phenotypic plasticity, and that is often deteriorated by postmortem damage to skeletal remains. These complexities raise the question of which skeletal structures most effectively track neutral population history. The cavity system of the inner ear (the so-called bony labyrinth) is a good candidate structure for such analyses. It is already fully formed by birth, which minimizes postnatal phenotypic plasticity, and it is generally well preserved in archaeological samples. Here we use morphometric data of the bony labyrinth to show that it is a surprisingly good marker of the global dispersal of modern humans from Africa. Labyrinthine morphology tracks genetic distances and geography in accordance with an isolation-by-distance model with dispersal from Africa. Our data further indicate that the neutral-like pattern of variation is compatible with stabilizing selection on labyrinth morphology. Given the increasingly important role of the petrous bone for ancient DNA recovery from archaeological specimens, we encourage researchers to acquire 3D morphological data of the inner ear structures before any invasive sampling. Such data will constitute an important archive of phenotypic variation in present and past populations, and will permit individual-based genotype-phenotype comparisons.

We welcome Ran Barkai’s thoughts (1) on the symbolic significance of the Konso bone handaxe that we recently reported (2). First, we agree that African Homo erectus at 1.4 Mya may have been considerably sophisticated in their cognitive capacities, including potential symbolic perception and behavior. Indeed, the technological context of the find suggests a higher level of cognition than previously thought, a point we further discuss below. Next, we note that, although bone marrow was exploited, fragmented fresh bones at processing sites are covered with soft tissue. One experimental work (3) reports that presence of periosteum precludes efficient controlled percussion, and another reports that weathered bone … [↵][1]1To whom correspondence may be addressed. Email: gsuwa{at}um.u-tokyo.ac.jp. [1]: #xref-corresp-1-1

Objectives The bony labyrinth of the inner ear has special relevance when tracking phenotypic evolution because it is often well preserved in fossil and modern primates. Here we track the evolution of the bony labyrinth of anthropoid primates during the Mio−Plio−Pleistocene—the time period that gave rise to the extant great apes and humans. Materials and Methods We use geometric morphometrics to analyze labyrinthine morphology in a wide range of extant and fossil anthropoids, including New World and Old World monkeys, apes, and humans; fossil taxa are represented by Aegyptopithecus, Microcolobus, Epipliopithecus, Nacholapithecus, Oreopithecus, Ardipithecus, Australopithecus, and Homo. Results Our results show that the morphology of the anthropoid bony labyrinth conveys a statistically significant phylogenetic signal especially at the family level. The bony labyrinthine morphology of anthropoids is also in part associated with size, but does not cluster by locomotor adaptations. The Miocene apes examined here, regardless of inferred locomotor behaviors, show labyrinthine morphologies distinct from modern great apes. Discussion Our results suggest that labyrinthine variation contains mixed signals and alternative explanations need to be explored, such as random genetic drift and neutral phenotypic evolution, as well as developmental constraints. The observed pattern in fossil and extant hominoids also suggests that an additional factor, for example, prenatal brain development, could have potentially had a larger role in the evolutionary modification of the bony labyrinth than hitherto recognized.

Metameric variation of molar size is in part associated with the dietary adaptations of mammals and results from slight alterations of developmental processes. Humans and great apes exhibit conspicuous variation in tooth morphology both between taxa and across tooth types. However, the manner in which metameric variation in molars emerged among apes and humans via evolutionary alterations in developmental processes remains largely unknown. In this study, we compare the enamel-dentine junction of the upper molars of humans—which closely correlates with morphology of the outer enamel surface and is less affected by wear—with that of the other extant hominoids: chimpanzees, bonobos, gorillas, orangutans, and gibbons. We used the morphometric mapping method to quantify and visualize three-dimensional morphological variation, and applied multivariate statistical analyses. Results revealed the following: 1) extant hominoids other than humans share a common pattern of metameric variation characterized by a largely linear change in morphospace; this indicates a relatively simple graded change in metameric molar shape; 2) intertaxon morphological differences become less distinct from the mesial to distal molars; and 3) humans diverge from the extant ape pattern in exhibiting a distinct metameric shape change trajectory in the morphospace. The graded shape change and lower intertaxon resolution from the mesial to distal molars are consistent with the concept of a ‘key’ tooth. The common metameric pattern observed among the extant nonhuman hominoids indicates that developmental patterns underlying metameric variation were largely conserved during ape evolution. Furthermore, the human-specific metameric pattern suggests considerable developmental modifications in the human lineage.

After a long period of inactivity, recent excavations at the late Miocene Maragheh Formation unexpectedly resulted in the discovery of the first fossil hominoid and second Mesopithecus remains from this area. The discovery motivated a new international initiative to conduct research in these rich fossil sites. These studies focused on the fossil hominoid and its locality, aiming to reveal more about the context of this fossil discovery. Detailed stratigraphy, sedimentology and magnetostratigraphy studies were conducted. New samples from volcaniclastic key horizons (pumice beds) in Dareh Gorg, where the hominoid fossil site is located, were dated by radiometric methods. The radiometric age determinations provide a firm tie-point for the geochronology. The polarity pattern in the palaeomagnetically investigated section corroborates the K-Ar results. The preliminary magnetostratigraphic results suggest that the hominoid locality can be correlated to the normal polarity chron C4n.2n (8.108–7.695 Ma), C4n.1n (7.642–7.528 Ma) or C3Br.1n (7.285–7.251 Ma), placing it at intervals corresponding to the mammal units MN11 or possibly early MN12. The study of fossil hominoid indicates broad affinities with a number of contemporaneous taxa from the Balkan-Iranian palaeoprovince, as well as Siwaliks and southeast Asia. A preliminary analysis of the accompanying (in situ) fauna at the hominoid site indicates the highest similarity of this level to Turolian hominoid- and Mesopithecus-bearing localities in Turkey, Greece and Bulgaria. However, some environmental differences are observed among these localities, based on their faunal structure and taxon properties, as well as in the different masticatory adaptations of their hominoids.

Miocene hominoid fossils are known from Africa and Eurasia, in the latter ranging widely from western Europe to Anatolia and from South Asia to Southeast/East Asia. Iran is located between the known western and eastern Eurasian hominoid distributions and is potentially important in understanding Miocene hominoid dispersal patterns. Maragheh is a late Miocene fossil locality in northwestern Iran, well known since the nineteenth century for its abundant mammalian fossils. However, until now, the only primate fossils reported from Maragheh or Iran were the Old World monkey Mesopithecus pentelicus. Recent field research at Maragheh has changed this situation by the discovery of the first hominoid fossil from Iran, a maxillary fragment with well-preserved second and third molars. Here, we provide a detailed description of this new specimen, comparing it with other similarly large-sized Eurasian late Miocene hominoids, Ouranopithecus, Ankarapithecus, Sivapithecus, and Indopithecus. Molar morphology of the Maragheh hominoid is similar to that of these Eurasian Miocene genera, with only minor differences in morphology and wear pattern. Based on the presently available materials, we tentatively prefer the interpretation that the Maragheh hominoid may be related more closely to either Ankarapithecus or Sivapithecus rather than to Ouranopithecus, but the fragmentary nature of the fossil makes evaluations difficult. Future discoveries of this Iranian hominoid are needed to determine its phylogenetic position with more certainty.

Proximal femoral morphology and associated musculature are of special relevance to the understanding of hominoid locomotor systems. Knowledge of bone-muscle correspondence in extant hominoids forms an important comparative basis for inferring structure-function relationships in fossil hominids. However, there is still a lack of consensus on the correspondence between muscle attachment sites and surface morphology of the proximal femoral diaphysis in chimpanzees. Two alternative observations have been proposed regarding the attachment site positions of gluteus maximus (GM) and vastus lateralis (VL) relative to two prominent surface features of the proximal femoral diaphysis, the lateral spiral pilaster and the inferolateral fossa. Here, we use a combination of virtual and physical dissection in an attempt to identify the exact correspondence between muscle attachment sites and osteological features in two specimens of Pan troglodytes verus. The results show that the insertion of the GM tendon is consistently inferolateral to the lateral spiral pilaster, and that a part of the inferolateral fossa consistently forms the attachment site of the VL muscular fibers. While overall musculoskeletal features are similar in the two specimens examined in this study, GM and VL exhibit different degrees of segregation at the level of the inferolateral fossa. One specimen exhibited tendinous GM fibers penetrating the posteromedial part of VL, with both GM and VL inserting at the inferolateral fossa. In the other specimen, GM and VL were separated by a lateral intermuscular septum, which inserted into the inferolateral fossa. Variation of proximal femoral muscle attachments in chimpanzees is thus greater than previously thought. Our results indicate that a conspicuous osteological feature such as the inferolateral fossa does not necessarily correspond to the attachment site of a single muscle, but could serve as a boundary region between two muscles. Caution is thus warranted when interpreting the surface topography of muscle attachment sites and inferring locomotor functions.

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In order to investigate molar enamel thickness and distribution in Gigantopithecus blacki, two maxillary and three mandibular molars were micro-CT scanned, and the 3-dimensional (3D) shape of the enamel crown cap was digitally reconstructed. Results show that G. blacki molars have very thick enamel, over 6 mm in places. 3D average thickness of the entire crown relative to crown size was shown to be comparable to that of modern Homo sapiens, and thinner than in the very thick enameled robust Australopithecus condition. Durability of the tooth, calculated as the enamel volume relative to maximum horizontal area of the crown, was shown to be comparable to that of fossil hominids, including Australopithecus robustus. The thick occlusal enamel of G. blacki molars was found to be accompanied by a buccolingual gradient in which thicker enamel occurs on the cusps of the “functional” side. This is associated with higher crown height on the “functional” side of the crown, and implies an adaptation to differential buccolingual wear. These results indicate that G. blacki molars were adapted to heavy wear, but probably in a manner that was different from Pliocene and Pleistocene hominids.

The early Pliocene African hominoid Ardipithecus ramidus was diagnosed as a having a unique phylogenetic relationship with the Australopithecus + Homo clade based on nonhoning canine teeth, a foreshortened cranial base, and postcranial characters related to facultative bipedality. However, pedal and pelvic traits indicating substantial arboreality have raised arguments that this taxon may instead be an example of parallel evolution of human-like traits among apes around the time of the chimpanzee-human split. Here we investigated the basicranial morphology of Ar. ramidus for additional clues to its phylogenetic position with reference to African apes, humans, and Australopithecus. Besides a relatively anterior foramen magnum, humans differ from apes in the lateral shift of the carotid foramina, mediolateral abbreviation of the lateral tympanic, and a shortened, trapezoidal basioccipital element. These traits reflect a relative broadening of the central basicranium, a derived condition associated with changes in tympanic shape and the extent of its contact with the petrous. Ar. ramidus shares with Australopithecus each of these human-like modifications. We used the preserved morphology of ARA-VP 1/500 to estimate the missing basicranial length, drawing on consistent proportional relationships in apes and humans. Ar. ramidus is confirmed to have a relatively short basicranium, as in Australopithecus and Homo. Reorganization of the central cranial base is among the earliest morphological markers of the Ardipithecus + Australopithecus + Homo clade.

We investigated mitochondrial DNA haplogroups of four Jomon individuals from the San- ganji shell mound in Fukushima, Tohoku district, Japan. Partial nucleotide sequences of the coding and control region of mitochondrial DNA were determined. The success rate of sequencing increased when we analyzed short DNA sequences. We identified haplogroups from all four samples that were ana- lyzed; haplogroup frequencies were 50% (n = 2) for N9b and 50% (n = 2) for M7a2. Haplogroup N9b has been previously observed in high frequencies in the other Tohoku Jomon, Hokkaido Jomon, Okhotsk, and Ainu peoples, whereas its frequency was reported to be low in the Kanto Jomon and the modern mainland Japanese. Sub-haplogroup M7a2 has previously been reported in the Hokkaido Jomon, Okhotsk, and modern Udegey (southern Siberia) peoples, but not in the Kanto Jomon, Ainu, or Ryukyuan peoples. Principal component analysis and phylogenetic network analysis revealed that, based on haplogroup frequencies, the Tohoku Jomon was genetically closer to the Hokkaido Jomon and Udegey people, than to the Kanto Jomon or mainland modern Japanese. The available evidence suggests genetic differences between the Tohoku and Kanto regions in the Jomon period, and greater genetic similarity between the Tohoku Jomon and the other investigated ancient (Hokkaido Jomon, Okhotsk) and modern (Siberian, Udegey in particular) populations. At the same time, the Tohoku and Hokkaido Jomon seem to differ in sub-haplotype representations, suggesting complexity in Jomon population structure and history.

Maritime adaptation was one of the essential factors that enabled modern humans to disperse all over the world. However, geographic distribution of early maritime technology during the Late Pleistocene remains unclear. At this time, the Indonesian Archipelago and eastern New Guinea stand as the sole, well-recognized area for secure Pleistocene evidence of repeated ocean crossings and advanced fishing technology. The incomplete archeological records also make it difficult to know whether modern humans could sustain their life on a resource-poor, small oceanic island for extended periods with Paleolithic technology. We here report evidence from a limestone cave site on Okinawa Island, Japan, of successive occupation that extends back to 35,000−30,000 y ago. Well-stratified strata at the Sakitari Cave site yielded a rich assemblage of seashell artifacts, including formally shaped tools, beads, and the world’s oldest fishhooks. These are accompanied by seasonally exploited food residue. The persistent occupation on this relatively small, geographically isolated island, as well as the appearance of Paleolithic sites on nearby islands by 30,000 y ago, suggest wider distribution of successful maritime adaptations than previously recognized, spanning the lower to midlatitude areas in the western Pacific coastal region.

Although dental size and morphology have contributed to population history studies in Japan, little attention has been paid to root size and dimensions. We report here computer tomography (CT)-based metrics of mandibular tooth roots in modern Japanese, Holocene Jomon, and Late Pleistocene Minatogawa human fossils (15000–20000 BP). Our results confirmed that, in terms of both mesiodistal cervical diameters and root lengths, the Jomon is overall smaller-toothed, with summed mesiodistal cervical diameters 4% smaller than in the modern Japanese. However, no significant differences were found in the M1, in both cervical diameter and root length. These results are comparable to the crown size differences reported in the two populations. There were no significant differences in root proportions (root length relative to cervical diameter) between the Jomon and the modern Japanese in each tooth element from I1 to M1, while an allometric root length reduction was observed in the M2 and M3 of the modern Japanese. This reflects distinct patterns of dental reduction in the two populations. The Late Pleistocene Minatogawa fossils were found to have larger cervical diameters and root lengths than either the modern Japanese or the Jomon, in some respects approximating the large-toothed Australian and/or earlier Late Pleistocene Homo sapiens conditions. This indicates a largely conservative dental system retained in the Minatogawa fossils, distinct from the Jomon condition.

In the present study, we estimated age at death of extinct deer (Cervus astylodon) excavated from two Late Pleistocene sites in Okinawa Island (the Hananda-Gama Cave and Yamashita-cho Cave I sites) from degree of molar wear. This was done using a regression equation of extant sika deer of known age, and deriving an age estimation equation based on M3 crown height applicable to fossil specimens. We then reconstructed mortality profiles using 45 and 88 individuals of the Hananda-Gama and Yamashita-cho assemblages, respectively, and compared the profiles with those of extant and archaeological (Jomon period) sika deer (C. nippon) populations. The reconstructed age profiles of both sites were strikingly different from the living and hunted Jomon period profiles in relative abundance of old adults. They were more similar to the attritional mortality profiles of the extant sika deer that died by natural causes (i.e. not by human or animal predation), but showed a further shift towards older age. Combined with the fact that there is no fossil evidence of medium- to large-sized carnivores on Okinawa Island during the Late Pleistocene, our results suggest that C. astylodon populations had extended longevity because of low predatory pressure, including that by Paleolithic human hunters.

Background Here we provide the most comprehensive study to date on the cranial ossification sequence in Lipotyphla, the group which includes shrews, moles and hedgehogs. This unique group, which encapsulates diverse ecological modes, such as terrestrial, subterranean, and aquatic lifestyles, is used to examine the evolutionary lability of cranial osteogenesis and to investigate the modularity of development. Results An acceleration of developmental timing of the vomeronasal complex has occurred in the common ancestor of moles. However, ossification of the nasal bone has shifted late in the more terrestrial shrew mole. Among the lipotyphlans, sequence heterochrony shows no significant association with modules derived from developmental origins (that is, neural crest cells vs. mesoderm derived parts) or with those derived from ossification modes (that is, dermal vs. endochondral ossification). Conclusions The drastic acceleration of vomeronasal development in moles is most likely coupled with the increased importance of the rostrum for digging and its use as a specialized tactile surface, both fossorial adaptations. The late development of the nasal in shrew moles, a condition also displayed by hedgehogs and shrews, is suggested to be the result of an ecological reversal to terrestrial lifestyle and reduced functional importance of the rostrum. As an overall pattern in lipotyphlans, our results reject the hypothesis that ossification sequence heterochrony occurs in modular fashion when considering the developmental patterns of the skull. We suggest that shifts in the cranial ossification sequence are not evolutionarily constrained by developmental origins or mode of ossification.

The Late Pleistocene human fossils recovered from the Minatogawa fissure in Okinawa Island are important in understanding the population history of the Japan archipelago. Based on high-resolution laser scanning, we conducted a three-dimensional (3-D) topographic evaluation of the glabellar and superciliary regions of the Minatogawa and Jomon crania. We aimed to address the question of whether the glabellar morphology of the Minatogawa crania can be seen as a possible ancestral condition of the Jomon people, or whether it more likely represents a distinct morphological pattern. In addition to comparative descriptions and evaluations of the visualized topography, we conducted principal components and cluster analyses using a data set of approximately 240 points located within a confined glabellofrontal area. Results indicate that the male Minatogawa I exhibits a distinct rhomboid to ovoid glabellosuperciliary prominence, in the form of an undifferentiated swollen structure that encompasses both glabellar and superciliary arch regions. Unlike the Jomon condition, this leads to a lack of concave inferolateral contour of the prominence and the virtually complete obliteration of bilateral superciliary expression. The Minatogawa II and IV female crania also exhibit the same morphological pattern at weaker levels. On the other hand, absolute glabellar projection of Minatogawa I is not as great as the developed Jomon examples. This indicates that it is the pattern that is distinctive of Minatogawa, rather than glabellar prominence itself.

The Late Pleistocene fossil human remains (individuals I–IV) of Minatogawa, Okinawa Island are important in addressing the population history of the Japanese archipelago and in understanding evolution of Homo sapiens in eastern Asia. This study is the first on Minatogawa I’s endocranial morphology, based on micro-computed tomography (micro-CT). We digitally reconstructed the Minatogawa I endocast, and created its physical model using a three-dimensional printer system. We compared the Minatogawa I endocast with available H. sapiens and archaic Homo endocasts. We found that Minatogawa I exhibits key derived endocranial features of H. sapiens, such as a highly elevated parietal, endocranial widening confined to a relatively anterior position, and a narrow internal occipital crest. The short, wide, and low proportioned Minatogawa I endocranium lies metrically at the margins of the modern human ranges of variation of this study. The Minatogawa I endocast exhibits a slightly underdeveloped frontal region with marked parasagittal ridges, a weak endocranial parietal boss, and a strong temporal bulge. It differs from Liujiang in the strong expression of these features as well as in overall metric proportions. A weak endocranial parietal boss and a strong temporal bulge are shared by Skhul V and Qafzeh 9, and may represent a primitive condition for H. sapiens in general.

Functionality of cheek teeth is essential for ruminants to masticate plant materials thoroughly and promote microbial degradation in their rumens. Thus, an excessive rate of tooth wear is expected to lead to premature loss of tooth functionality, and hence to reduced longevity. So far, however, the relationships between food habits, molar wear and longevity have not been investigated. We first compared molar wear rates among nine sika deer Cervus nippon populations with different food habits. We then investigated correlations between molar wear rate and two ecological factors, percentage of graminoids in diet and annual precipitation, relating to intrinsic and extrinsic abrasiveness of the ingested food, respectively. Secondly, we estimated ‘retained molar durability’ (molar height at a given age divided by wear rate) at successive ages for each population, and tested for correlation between molar durability and life expectancy among populations. The M1 and M3 wear rates differed among the populations and showed a positive correlation with graminoid consumption and a negative correlation with precipitation, suggesting that both ecological factors influence molar wear rates in the Japanese sika deer. M3 durability had a stronger correlation with life expectancy than M1 durability, especially at the older age stages. This implies that the influence of M3 durability on life expectancy becomes stronger at the time when the M1 is severely worn and loses its functionality, and is therefore more important for life span elongation than the M1. These results are concordant with the fact that the M3 is the most hypsodont molar in many ungulates. In the Japanese sika deer, microevolutionary acquisition of hypsodonty appears to be the case in a northern population (the Kinkazan Island), whose molar wear rates are extremely rapid due to their food habits.

成人期縄文人の四肢骨骨幹部は現代日本人より断面が太く扁平であることが知られている。本研究では，胎生8ヶ月から生後3ヶ月にわたる縄文人と現代日本人の主要四肢骨を用いて，骨幹中央部の各種の断面特性値を群間比較することにより，従来指摘されてきた頑丈性と扁平性の成因について改めて考察した。資料は縄文人49個体，現代日本人185個体の上腕骨，橈骨，尺骨，大腿骨，脛骨，腓骨を用いた。内部断面計測では高精細のマイクロCT装置を導入した。解析においては各四肢骨の骨幹長を相対的な年齢指標とみなし，骨幹長を共変量とする共分散分析を実施した。その結果，全身の四肢骨にわたり，縄文人の骨幹は一貫して現代日本人より外径が太く，断面上の骨量が多く，力学的に頑丈な傾向にあり，さらには二集団の断面拡大パターンの間に有意な違いはないことがわかった。二集団の外部形状と骨分布形状は胎児・乳児期を通じてほとんど変化しておらず，大半の四肢骨の断面示数において有意な集団差は認められなかった。ただし，縄文人の大腿骨の外部形状は一貫して現代日本人より前後方向に扁平であることがわかった。本研究では，成人期縄文人で指摘されてきた骨幹部形質のうち，外径の太さ，骨量の多さ，さらに大腿骨骨体上部の相対的に前後径が短い（内外側方向に長い）扁平さに関しては，既に胎生期にそれらの傾向が存在し，発生初期におけるパターン形成の影響が示唆された。

The juvenile mandible of the modern Japanese has a lower symphysis than that of the prehistoric Jomon, while the adult symphysis is conversely higher in the modern Japanese. This cannot be explained from population differences in masticatory environments. As an alternative factor that may influence symphyseal height, we examined tooth crypt size and placement patterns in the skeletal growth series of the two populations. Results showed that although the Jomon mandible had larger bicanine breadth than in the modern Japanese during growth, the modern Japanese has faster growing anterior teeth that became larger than those of the Jomon by the time of eruption, necessitating greater space. This is expressed as the faster growth rate of anterior alveolar height in the modern Japanese, measured as corpus height above the mandibular canal. Canine eruption distance and root length were greater in the modern Japanese than in the Jomon, corresponding to the increased difference of anterior corpus height between the two populations after canine eruption. However, the influence of tooth root length on anterior corpus height during later growth cannot be evaluated by this study. The present study suggests that the size and spatial dispositions of the developing anterior teeth have significant effects on symphyseal dimensions of the mandible until the time of tooth eruption.

The Middle Awash Ardipithecus ramidus sample comprises over 145 teeth, including associated maxillary and mandibular sets. These help reveal the earliest stages of human evolution. Ar. ramidus lacks the postcanine megadontia of Australopithecus . Its molars have thinner enamel and are functionally less durable than those of Australopithecus but lack the derived Pan pattern of thin occlusal enamel associated with ripe-fruit frugivory. The Ar. ramidus dental morphology and wear pattern are consistent with a partially terrestrial, omnivorous/frugivorous niche. Analyses show that the ARA-VP-6/500 skeleton is female and that Ar. ramidus was nearly monomorphic in canine size and shape. The canine/lower third premolar complex indicates a reduction of canine size and honing capacity early in hominid evolution, possibly driven by selection targeted on the male upper canine.

Genomic comparisons have established the chimpanzee and bonobo as our closest living relatives. However, the intricacies of gene regulation and expression caution against the use of these extant apes in deducing the anatomical structure of the last common ancestor that we shared with them. Evidence for this structure must therefore be sought from the fossil record. Until now, that record has provided few relevant data because available fossils were too recent or too incomplete. Evidence from Ardipithecus ramidus now suggests that the last common ancestor lacked the hand, foot, pelvic, vertebral, and limb structures and proportions specialized for suspension, vertical climbing, and knuckle-walking among extant African apes. If this hypothesis is correct, each extant African ape genus must have independently acquired these specializations from more generalized ancestors who still practiced careful arboreal climbing and bridging. African apes and hominids acquired advanced orthogrady in parallel. Hominoid spinal invagination is an embryogenetic mechanism that reoriented the shoulder girdle more laterally. It was unaccompanied by substantial lumbar spine abbreviation, an adaptation restricted to vertical climbing and/or suspension. The specialized locomotor anatomies and behaviors of chimpanzees and gorillas therefore constitute poor models for the origin and evolution of human bipedality.

Hominid fossils predating the emergence of Australopithecus have been sparse and fragmentary. The evolution of our lineage after the last common ancestor we shared with chimpanzees has therefore remained unclear. Ardipithecus ramidus , recovered in ecologically and temporally resolved contexts in Ethiopia’s Afar Rift, now illuminates earlier hominid paleobiology and aspects of extant African ape evolution. More than 110 specimens recovered from 4.4-million-year-old sediments include a partial skeleton with much of the skull, hands, feet, limbs, and pelvis. This hominid combined arboreal palmigrade clambering and careful climbing with a form of terrestrial bipedality more primitive than that of Australopithecus . Ar. ramidus had a reduced canine/premolar complex and a little-derived cranial morphology and consumed a predominantly C 3 plant–based diet (plants using the C 3 photosynthetic pathway). Its ecological habitat appears to have been largely woodland-focused. Ar. ramidus lacks any characters typical of suspension, vertical climbing, or knuckle-walking. Ar. ramidus indicates that despite the genetic similarities of living humans and chimpanzees, the ancestor we last shared probably differed substantially from any extant African ape. Hominids and extant African apes have each become highly specialized through very different evolutionary pathways. This evidence also illuminates the origins of orthogrady, bipedality, ecology, diet, and social behavior in earliest Hominidae and helps to define the basal hominid adaptation, thereby accentuating the derived nature of Australopithecus .

An increasing number of studies determine endocranial capacity (ECC) digitally using serial computed tomographic (CT) scan data. However, the multiple causes of errors inherent in such measurements and the resulting degree of accuracy have not yet been fully examined. In the present study, five observers estimated the ECCs of two modern human crania by segmentation of CT data (voxel size 0.380 mm) and by means of the conventional millet seed method. The ECC estimations were much more consistent in the CT-based (technical error, TEM = 1.4 cc) than the millet seed (TEM = 11.8 cc) methods. The estimated capacities also tended to be larger in the latter, suggesting possible systematic bias. Next, the causes and degree of error in the CT-based method were examined. Error due to size calibration of the CT images was no more than 3 cc (± 1.5 cc) per 1000 cc. Errors involved in delineating the endocranial cavity were evaluated as follows. First, we adopted a segmentation routine in which a single global threshold value was applied to most of the volume, and then supplemented locally by more appropriate values in the regions where the global value was insufficient. We then estimated the potential error introduced by choosing a global threshold value. We found this to be within 5 cc (per 1000 cc). This error range increased to 7.5 cc (per 1000 cc), when using a lower resolution data set (slice thickness 1.14 mm). Another source of interobserver error involves the blocking of foramina and canals, which we estimated to be less than 2 cc (per 1000 cc). Adding these various effects, our investigations indicate that ECC estimations based on high-resolution CT data are accurate to within ± 5 cc per 1000 cc. Finally, we reevaluated the ECC of the Minatogawa 1 skull to be 1335 cc (with a probable range of 1327–1343 ± 5 cc), considerably smaller than the originally reported value of 1390 cc obtained by the millet seed method.

Timing the divergence between the gorilla, chimp and human lineages has been the province of molecular phylogeny largely unconstrained by fossil evidence. Gen Suwa et al. now present fossil teeth from Ethiopia which look very similar to those of a modern gorilla, even though they are 10 million years old. If the teeth, assigned to a new species of fossil ape, are from a creature on the gorilla lineage, then the divergence between gorillas and the chimp–human stock must have happened before that time, constraining divergence dates reached through the comparison of contemporary genetic sequences. Fossil teeth from Ethiopia are presented that look very similar to those of a modern gorilla, despite being 10 million years old. If the teeth, assigned to a new species of fossil ape, come from a creature on the gorilla lineage, then the divergence between gorillas and the chimp–human stock must have happened before that time, constraining divergence dates reached through the comparison of contemporary genetic sequences. With the discovery of Ardipithecus, Orrorin and Sahelanthropus1,2,3,4,5,6,7, our knowledge of hominid evolution before the emergence of Pliocene species of Australopithecus8,9 has significantly increased, extending the hominid fossil record back to at least 6 million years (Myr) ago. However, because of the dearth of fossil hominoid remains in sub-Saharan Africa spanning the period 12–7 Myr ago, nothing is known of the actual timing and mode of divergence of the African ape and hominid lineages. Most genomic-based studies suggest a late divergence date—5–6 Myr ago and 6–8 Myr ago for the human–chimp and human–gorilla splits, respectively10,11,12,13,14—and some palaeontological and molecular analyses hypothesize a Eurasian origin of the African ape and hominid clade15,16. We report here the discovery and recognition of a new species of great ape, Chororapithecus abyssinicus, from the 10–10.5-Myr-old deposits of the Chorora Formation at the southern margin of the Afar rift. To the best of our knowledge, these are the first fossils of a large-bodied Miocene ape from the African continent north of Kenya. They exhibit a gorilla-sized dentition that combines distinct shearing crests with thick enamel on its ‘functional’ side cusps. Visualization of the enamel–dentine junction by micro-computed tomography reveals shearing crest features that partly resemble the modern gorilla condition. These features represent genetically based structural modifications probably associated with an initial adaptation to a comparatively fibrous diet. The relatively flat cuspal enamel–dentine junction and thick enamel, however, suggest a concurrent adaptation to hard and/or abrasive food items. The combined evidence suggests that Chororapithecus may be a basal member of the gorilla clade, and that the latter exhibited some amount of adaptive and phyletic diversity at around 10–11 Myr ago.

Morphological comparisons of the sika deer Cervus nippon mandible and molars were conducted between two (northern and southern) Japanese subspecific lineages and among local populations of different (‘grazer’ or ‘intermediate feeder’) feeding types. The northern lineage showed greater M1 breadth, M3 hypsodonty and mandibular corpus height than the southern lineage. Such differences were not observed between the ‘grazer’ and ‘intermediate feeder’ populations of the northern lineage. However, a northern population, which inhabits a particularly harsh environment (Kinkazan Island), had the largest values of relative molar size and hypsodonty, although this was not statistically significant. These results imply that, in the Japanese sika deer, the selective pressures acting on the current ‘grazer’ populations are not strong enough to bring out noticeable adaptive change in molar size and hypsodonty, but adaptive change in these traits may occur in an environment that promotes excessive molar wear, more than that seen in the current sika deer habitats of Japan. Combined with what is known of the Pleistocene history of the sika deer, we infer that the ancestral population of the northern Japanese lineage likely acquired their relatively larger and more hypsodont molars in an extremely harsh environment during the last or previous glacial periods.

A substantial revision to the age of the Chorora Formation, Ethiopia, constraining the deposits to around 8 million years old and forming a revised age constraint for the human–gorilla lineage split. The Chorora Formation, at the southern margin of the Afar rift in Ethiopia, has been regarded as providing a fossil record approximately 10.5 million years old. In 2007, Gen Suwa et al. reported the discovery of a fossil relative of the gorilla in the Chorora Formation. Thought to have been between 10 and 10.5 million years old, Chororapithecus abyssinicus was seen a primitive member of the gorilla clade. Now Suwa and colleagues report new field observations, geochemical, magnetostratigraphic and radioisotopic data, consistent with a substantial revision of the age of the Chorora Formation to around 8 million years old. This lifts Chororapithecus from a time when apes were common in Eurasia, to one in which evidence for fossil apes is scarce. The attribution to the gorilla lineage looks all the more important as it helps constrain the split between gorillas and the lineage leading to hominins and chimpanzees, and suggests that this split occurred in Africa. The palaeobiological record of 12 million to 7 million years ago (Ma) is crucial to the elucidation of African ape and human origins, but few fossil assemblages of this period have been reported from sub-Saharan Africa. Since the 1970s, the Chorora Formation, Ethiopia, has been widely considered to contain ~10.5 million year (Myr) old mammalian fossils1,2,3,4,5,6,7. More recently, Chororapithecus abyssinicus, a probable primitive member of the gorilla clade6, was discovered from the formation. Here we report new field observations and geochemical, magnetostratigraphic and radioisotopic results that securely place the Chorora Formation sediments to between ~9 and ~7 Ma. The C. abyssinicus fossils are ~8.0 Myr old, forming a revised age constraint of the human–gorilla split. Other Chorora fossils range in age from ~8.5 to 7 Ma and comprise the first sub-Saharan mammalian assemblage that spans this period. These fossils suggest indigenous African evolution of multiple mammalian lineages/groups between 10 and 7 Ma, including a possible ancestral-descendent relationship between the ~9.8 Myr old Nakalipithecus nakayamai8 and C. abyssinicus. The new chronology and fossils suggest that faunal provinciality between eastern Africa and Eurasia had intensified by ~9 Ma, with decreased faunal interchange thereafter9,10,11,12. The Chorora evidence supports the hypothesis of in situ African evolution of the Gorilla–Pan–human clade, and is concordant with the deeper divergence estimates of humans and great apes based on lower mutation rates of ~0.5 × 10−9 per site per year (refs 13, 14, 15).

Australopithecus fossils were regularly interpreted during the late 20th century in a framework that used living African apes, especially chimpanzees, as proxies for the immediate ancestors of the human clade. Such projection is now largely nullified by the discovery of Ardipithecus . In the context of accumulating evidence from genetics, developmental biology, anatomy, ecology, biogeography, and geology, Ardipithecus alters perspectives on how our earliest hominid ancestors—and our closest living relatives—evolved.

The 200-m-thick fossiliferous Konso Formation and overlying terrace deposits, which crop out at the end of the southern sector of the Main Ethiopian Rift (MER), contain more than 30 distal tephra layers. Local and regional tephra correlations of more than 20 tephra units were established using major and trace element data of discrete and purified bulk glass samples within the Konso study area. Eleven correlative marker tuffs were recognized in stratigraphic sections of both the Konso Formation and the Omo-Turkana Basin sediments in southern Ethiopia and northern Kenya. The Turoha, Hope, Ivory, Bright White, and Boleshe Tuffs in the Konso Formation, and the Upper White Tuff in the overlying terrace deposits are securely correlated with the KBS, Akait, Lokapetamoi, Chari, Lower Nariokotome, and Silbo Tuffs of the Omo-Turkana Basin, using least mobile major elements (CaO, Fe2O3*, and TiO2) and geochronology. Preliminary correlations are also suggested between the Konso Formation distal tephra and proximal units of the Quaternary caldera-forming silicic centers in the central sector of the MER. The strongly peralkaline tuffs of the Konso Formation are compositionally similar to proximal eruptions mostly located along the Quaternary axial rift zone of the southern, central, and northern sectors of the MER. The tephra correlation provides information about the temporal and spatial features of the volcanic and tectonic processes recorded in the evolving basins. Thickness and sedimentation rate were determined for both the Konso Formation and the Omo-Turkana Basin sections, measured between the Turoha (=KBS; 1.91 ± 0.03 Ma) and the Bright White (=Chari; 1.40 ± 0.02 Ma) Tuffs. Although the lithostratigraphic sequence at the Konso study area is younger, sedimentation rate within the Konso Formation was comparable to that of the Koobi Fora Formation, higher in the Nachukui Formation, and lower in the Shungura Formation. Local and regional differences in thickness and sedimentation rates within the Plio–Pleistocene deposits of the Konso, Shungura, Nachukui, and Koobi Fora Formations may be attributed to erosion associated with increased topographic gradients maintained by continued subsidence mostly along axial fault zones of basins and uplift along the margins of the broadly rifted zone of the Omo-Turkana Basin and the southern sector of the MER.

Fossil hominids from Gamedah, a Pliocene locality in the Middle Awash study area of the Ethiopian Afar depression, are described and compared with other fossil hominids. The specimens are a mandible and a parietal fragment dating to approximately 2.5 million years ago. The mandible is not a robust Australopithecus and is from an individual smaller than the nearly contemporary holotype of Australopithecus garhi. There is, as yet, no evidence of ‘robust’ Australopithecus north of the Konso site in Ethiopia. Whether this is a real biogeographical phenomenon or an artefact of sampling is presently impossible to determine.

The Pliocene–Pleistocene Konso Formation defined here is >180 m thick and is extensively exposed in the Konso area at the southernmost part of the Ganjuli graben of the Main Ethiopian Rift. The Konso area is known for its abundant vertebrate fossils, including those of Homo erectus and Australopithecus boisei, and its rich Acheulean archaeological assemblages. The fluvial, floodplain, lake margin, and lacustrine sediments of the formation were mostly deposited between 1.9 and 1.4 Ma, based on single-crystal 40Ar/39Ar ages of interbedded marker tuffs. The formation is subdivided into the Sorobo, Turoha, Kayle, and Karat Members, in ascending stratigraphic order. Each member contains dark brown or dark grey clay beds of lake margin and/or lacustrine origin, suggesting the recurrence of lake environments. Most of the fossils and artifacts derive from whitish grey or brown silt, sand, and gravel beds widely exposed between the finer sediments. These beds appear to have been deposited in an emerging marginal floodplain following repeated recession of the palaeo-lake. The depositional history of the Konso Formation reveals aspects of Quaternary rifting at the southern terminus of the Main Ethiopian Rift. Rifting, subsidence, and sedimentation in the Ganjuli graben occurred in the Konso area mainly between 1.9 and 1.4 Ma, while active faulting with associated volcanism during the Pleistocene was mostly confined to the middle part of the graben between Lakes Abaya and Chamo and to the Segen basin east of Konso. A shift of rift-related faulting and subsidence from the Konso area eastward to the Segen basin is likely to have resulted in the erosion and exposure of the fossiliferous Konso Formation.

Radiocarbon ages were determined for 25 samples of human skeletal remains previously assigned or attributable to the Yayoi period (tentatively considered ca. 500 BC to 300 AD) of the Kanto district, Japan. Suzuki (1969) and others, predominantly on cranial morphology, recognized that the Kanto Yayoi series contains three morphological groups: the native Jomon, transitional, and Kofun types. Morphological variation of the Kanto Yayoi people was considered to be chronologically based and formed the basis of Suzuki’s transformation hypothesis of the origin of the Japanese, which assumed limited influence, in eastern Japan, from continental immigrants. The 14C dates of the present study, determined for fragmentary postcranial elements of the same general assemblage, showed that these ‘Yayoi’ series, in part, contain skeletal remains of different ages, including those attributable to the Jomon and Kofun periods. All specimens from the Sano site that were examined were found to most likely derive from the Jomon period, while the dated Ourayama and Iwatsubo remains are best interpreted to be of Yayoi age. The Awajinsha and Bishamon samples were found to be of mixed chronological compositions. The implications of these results are discussed.

Enamel thickness was investigated in the mesial cusp section of 167 unworn human molars by means of non-destructive micro-CT based methodology. Serial sections of the entire crown were taken at a voxel resolution of 28 microns, and the initial volume data set of each molar was standardized in orientation to obtain a vertical section that accurately contains the dentine tips of the two mesial cusps. Enamel thickness at the cusp tips, occlusal basin, and lateral crown face was measured in the mesial cusp section and in sections offset from that section by 0.6 mm. We found that thickness at the cusp tips may be overestimated in offset sections by up to about 1 mm, and those of the occlusal basin overestimated or underestimated by up to about 0.5 mm. We also found that maximum ‘radial’ thickness of the lateral crown face was least affected by section position, usually with discrepancies of less than about 0.1–0.2 mm. In all serial positions in both upper and lower molars, a ‘functional’ (lingual in uppers and buccal in lowers) to ‘non-functional’ side gradient in enamel thickness was observed in cusp tip, occlusal basin, and lateral crown face enamel, with the exception of the characteristically thin enamel at the protoconid and paracone cusp tips. Serial differences in thickness were seen between the thinner M1 and the two posterior molars in many but not all measures of thickness, the pattern of which appears to be influenced by the thin M1 mesiobuccal cusp enamel. Individual variation of maximum lateral thickness, the least variable measure of thickness, was found to be substantial (a 30–60% range) even with serial and buccolingual positions controlled. Correlation between whole crown average enamel thickness and maximum lateral thickness was high, indicating that the latter is a potentially useful predictor of overall enamel thickness of the molar crown. The present results indicate that interspecific comparisons of enamel thickness must be made with careful attention to positional placement of thickness measures, potential serial differences, and intraspecific variation.

The thickness of mammalian tooth enamel plays a prominent role in paleontology because it correlates with diet, and thicker enamel protects against tooth breakage and wear. Hominid evolutionary studies have stressed the importance of this character for over 30 years, from the identification of "Ramapithecus "a s an early Miocene hominid, to the recent discovery that the earliest hominids display molar enamel intermediate in thickness between extant chimpanzees and Australopithe- cus. Enamel thickness remains largely unexplored for nonhominoid primate fossils, though there is significant variation across modern species. Despite the importance of enamel thickness variation to primate evolution, the mechanisms underlying variation in this trait have not yet been elucidated. We report here on the first quantita- tive genetic analysis of primate enamel thickness, an analysis based on 506 pedigreed baboons from a captive breeding colony. Computed tomography analysis of 44 Pa- pio mandibular molars shows a zone of sufficiently uni- form enamel thickness on the lateral surface of the proto- conid. With this knowledge, we developed a caliper metric measurement protocol for use on baboon molars worn to within this zone, enabling the collection of a data set large enough for genetic analyses. Quantitative genetic analy- ses show that a significant portion of the phenotypic vari- ance in enamel thickness is due to the additive effects of genes and is independent of sex and tooth size. Our models predict that enamel thickness could rapidly track dietary adaptive shifts through geological time, thus increasing the potential for homoplasy in this character. These re- sults have implications for analyses of hominoid enamel thickness variation, and provide a foundation from which to explore the evolution of this phenotype in the papionin fossil record. Am J Phys Anthropol 122:000 - 000, 2003. © 2003 Wiley-Liss, Inc.

Mammalian fossils of the Konso Formation (southwestern Main Ethiopian Rift) derive from stratigraphic intervals dated to between 2.0 Ma and younger than 1.3 Ma. Systematic paleontological collecting resulted in almost 8,000 identifiable mammalian specimens representing 8 orders, 22 families, and more than 68 species including Australopithecus boisei and Homo erectus. Despite geographic proximity to the Turkana Basin (approximately 200 km), aspects of the Konso fauna are distinctive, with its 1.9–1.7 Ma assemblage showing some degree of endemism. Bovids Megalotragus, Parmularius altidens, Parmularius eppsi, Menelikia, and Pelorovis, all common at Turkana and/or Olduvai, are rare or absent at Konso, while Parmularius cf. pandatus, Simatherium, and Notochoerus n. sp. of the Konso assemblages are the youngest known records of these taxa in eastern Africa. The dominant suid of this assemblage is Kolpochoerus majus, a previously poorly known taxon. Subsequent to circa 1.7 Ma, an influx of external elem...

The origin of anatomically modern Homo sapiens and the fate of Neanderthals have been fundamental questions in human evolutionary studies for over a century. A key barrier to the resolution of these questions has been the lack of substantial and accurately dated African hominid fossils from between 100,000 and 300,000 years ago. Here we describe fossilized hominid crania from Herto, Middle Awash, Ethiopia, that fill this gap and provide crucial evidence on the location, timing and contextual circumstances of the emergence of Homo sapiens. Radioisotopically dated to between 160,000 and 154,000 years ago, these new fossils predate classic Neanderthals and lack their derived features. The Herto hominids are morphologically and chronologically intermediate between archaic African fossils and later anatomically modern Late Pleistocene humans. They therefore represent the probable immediate ancestors of anatomically modern humans. Their anatomy and antiquity constitute strong evidence of modern-human emergence in Africa.

A Homo erectus calvarium [Sambungmacan 4 (Sm 4)] was recovered from Pleistocene sediments at Sambungmacan in central Java. Micro–computed tomography analysis shows a modern human–like cranial base flexion associated with a low platycephalic vault, implying that the evolution of human cranial globularity was independent of cranial base flexion. The overall morphology of Sm 4 is intermediate between that of earlier and later Javanese Homo erectus ; apparent morphological specializations are more strongly expressed in the latter. This supports the hypothesis that later Pleistocene Javanese populations were substantially isolated and made minimal contributions to the ancestry of modern humans.

The past decade has seen an incredible amount of new hominid fossils recovered from the late Miocene and Pliocene of Africa. This paper reviews these discoveries. It is suggested that there exists little support for the often stated view of considerable phyletic diversity in the hominid fossil record.