New reconstruction of the moroto hominoid snout and a reassessment of its affinities toAfropithecus turkanensis

Two previous reconstructions of the Moroto hominoid palate and face made during the late 1960s suffer from several errors, in particular the angle at which the facial skeleton was hafted onto the palate, and the orientation of the canines, among others. A new reconstruction is based on the discovery that there is a good contact about 1cm logn between the palatal and facial pieces, which reveals that the snout was low and elongated as inAfropithecus turkanensis. Addition of a fragment of the right orbit reveals that the interorbital region was wide as inA. turkanensis. The remaining differences between the skulls from Moroto and Kalodirr are due to five factors:−1) pathology of the Moroto right premaxilla following ante-mortem loss of the right I¹, which led to abnormal enlargement of the right half of the nasal cavity, 2) the incisive foramina of the Moroto palate are damaged, making them appear considerably larger than they were in life, 3) damage to the upper portions of the nasal aperture making it look higher than it would in life, 4) plastic deformation and crushing of the Kalodirr specimen has greatly reduced the width of the palate and has led to the cheek tooth rows converging to the rear, and 5) the slightly larger and ontogenetically older status of the Moroto individual. Resemblances between the Moroto and Kalodirr specimens far outweight the purported or real differences and it is concluded thatMorotopithecus bishopi is a junior subjective synonym ofAfropithecus turkanensis. The sites of Moroto and Kalodirr are unlikely to differ greatly in age (certainly not as much as 4 Ma).     

Functional structure of the skull in hominoidea

Finite elements stress analysis (FESA) was used to investigate the flow of compressive forces which occur if a homogenous, three-dimensional body representing the skull is loaded by simulated bite forces against the tooth row. Model 1 represents the snout alone. Bite forces are applied simultaneously, but increase rearward. Stresses in the model concentrate along the anterior contour and the lower surface of the model, leaving unstressed a nasal opening and a wide naso-oral connection. Model 2 represents the facial region, as far as the temporomandibular joint. The orbits and the nasal cavity are assumed to be present a priori. Model 3 applies reactions to the bite forces in the temporal fossa, corresponding to the origins of the masticatory muscles. Regions of the model under compressive stress correspond closely to the arrangement of bony material in a hominoid skull. If only the stress-bearing finite elements on each section are combined, and the stress-free parts neglected, the resulting three-dimensional shape is surprisingly similar to a hominoid skull. If bite forces are applied to parts of the tooth row only, the stress patterns are lower, asymmetrical and do not spread into all regions that are stress-bearing in simultaneous biting on all teeth. In model 2, the highest stresses occur at the tooth roots and along the forehead on top of the nasal roof. There are no marked stress concentrations on top of the orbits. The resulting shape resembles that of an orang-utan. In model 3, the highest stresses also occur at the tooth roots, but the circles of force mostly close below the brain case, so that the stress concentration in the forehead region remains much less marked. In this model, however, the stress concentrations are very similar to hollow brow ridges. The entire resulting shape resembles that of gorilla or chimpanzee skulls. A typical gracile australopithecine skull (STS-5) also shows clear similarities to the patterns of stress flow in our models. Compared to our earlier study of the modern human skull, differences relate to: the relative length and width of the dental arcade, the relative size of the brain case and the position of the arcade relative to the brain case. It seems that these traits are the points of attack of selective pressures, while all other morphological details are simply consequences of stress flow.     

Paleoclimatic Variation and Brain Expansion during Human Evolution

One of the major adaptations during the evolution of Homo sapiens was an increase in brain size. Here we present evidence that a significant and substantial proportion of variation in brain size may be related to changes in temperature. Based on a sample of 109 fossilized hominid skulls, we found that cranial capacities were highly correlated with paleoclimatic changes in temperature, as indexed by oxygen isotope data and sea-surface temperature. Indeed, as much as 52% of the variance in the cranial capacity of these skulls could be accounted for by temperature variation at 100 ka intervals. As an index of more short-term seasonal fluctuations in temperature, we examined the latitude of the sites from which the crania originated. More than 22% of the variance in cranial capacity of these skulls could be accounted for by variation in equatorial distance.     

The Ear Region of the Pen-tailed Treeshrew, Ptilocercus lowii Gray, 1848 (Placentalia, Scandentia, Ptilocercidae)

The ear region of the pen-tailed treeshrew, Ptilocercus lowii Gray, 1848 (Scandentia, Ptilocercidae), is described and illustrated in detail based on five museum specimens from the National Museum of Natural History, two with the auditory bulla removed exposing the intratympanic surfaces. Soft tissues (arteries, veins, nerves, and muscles) are reconstructed onto the adult skulls based on published reports of these elements in a fetal P. lowii. Comparisons are made with four specimens of the common treeshrew, the tupaiid Tupaia glis (Diard, 1820), from the Carnegie Museum of Natural History, including one with the auditory bulla removed. The mammalian ear region widely is regarded to be a rich source of characters for phylogenetic analysis. This study supports this view by identifying numerous features that are shared between the two treeshrews as well as numerous features that distinguish them. Several features used in the past to distinguish tupaiid treeshrews from primates are found to differ between P. lowii and T. glis: the composition of the bony tubes for the internal carotid artery and the composition of the intrabullar septa and spaces. Despite the compositional differences, it seems likely that the bony carotid tubes and intrabullar septa and spaces shared by P. lowii and T. glis occurred in their common ancestor. Evaluating the utility of these and other ear region features awaits future phylogenetic analysis of treeshrews and related Euarchontoglires.     

“Meganthropus” cranial fossils from Java

There are now twelve significant hominid cranial fossils from the Lower and Middle Pleistocene of Java, all but two being from the Sangiran site. Most of this material is well-known in the literature, but three skulls, possibly representing “Meganthropus” are here described in detail for the first time. Most scholars have assigned them all toHomo erectus, while others have suggested that they represent as many as four different hominoid taxa. The author argues that they represent two possible species of hominids. “Meganthropus” I, II, and III are more massive than any of the knownH. erectus specimens. They are also relatively higher vaulted, apparently smaller brained, and have unusually thick lower occipital planes. “Meganthropus” may represent a species that separated fromH. erectus upon its arrival to Java.     

Sexual dimorphism of the canine roots in theMacaca fuscata

In situ radiographic analysis of the maxillary canines ofMacaca fuscata was conducted on 88 specimens in 44 individuals (23 dry skulls and 21 live animals) in order to examine the number of roots. The left canines were then extracted from ten female skulls for measurement, further radiographic examination, and visual morphological observation. The results showed a clear sexual dimorphism in root morphology: all male canines were clearly distinguished as single-rooted from the radiograph, whereas more than 40% of the female canines were double-rooted. Variation was also found among the single-rooted female canines, in that some of these teeth appeared to have a bifurcated canal. This sexual dimorphism in the number of maxillary canine roots and the individual variation found among the females in root and canal morphology are previously unreported for this species. No observations were attempted on mandibular canines, however, because of the incomplete nature of the sample.     

Tooth Wear Difference Between the Yuanmou Hominoid and <Emphasis Type="Italic">Lufengpithecus</Emphasis>

The Late Miocene hominoids recovered from Lufeng (Lufengpithecus) and Yuanmou of Yunnan Province, China, are among the most numerous hominoid fossils in Eurasia. They have yielded critical evidence for the evolutionary history, biogeography and paleobiology of Miocene hominoids. We examined and compared the wear pattern and differences of 804 molars of the Yuanmou hominoid and Lufengpithecus. Our results indicate that both the upper and lower molars of the Yuanmou hominoids were more heavily worn than those of Lufengpithecus. The wear patterns of the individual molars between the Yuanmou hominoid and Lufengpithecus also are different. The heaviest wear of lower molars of the Yuanmou hominoid occur in M₂, followed by M₁ and M₃. In Lufengpithecus, M₁ and M₃ were more heavily worn than M₂. There are differences in wear between the upper and lower molars for the two hominoids. Among the various factors related to tooth wear, we suggest that the main reason for the tooth wear differences between the Yuanmou hominoid and Lufengpithecus may be that they had different diets. More soft dietary items like leaves and berries were probably consumed by Lufengpithecus, and the Yuanmou hominoid may mainly have feed on harder or frugivorous diets. This result complements findings from previous studies of tooth size proportion, and the development of lower molar shearing crests in the 2 samples. Enamel thickness, living environment, behavior patterns, and population structure also might account for dental wear differences between the Yuanmou hominoid and Lufengpithecus.     

香港地区现代人头骨的研究：性别和地区类型的判别分析

本文报告了香港地区现代中国人头骨测量性状的性别差异情况和香港与太原的男性头骨的差异情况。在此基础上,使用判别分析的方法建立了各自的判别函数,正判率分别达到93.1％和85.3％。它们分别适用于华南头骨的性别鉴定和华南与华北男性头骨的区分。     

Phenotypic integration of the cervical vertebrae in the Hominoidea (Primates)

Phenotypic integration and modularity represent important factors influencing evolutionary change. The mammalian cervical vertebral column is particularly interesting in regards to integration and modularity because it is highly constrained to seven elements, despite widely variable morphology. Previous research has found a common pattern of integration among quadrupedal mammals, but integration patterns also evolve in response to locomotor selective pressures like those associated with hominin bipedalism. Here, I test patterns of covariation in the cervical vertebrae of three hominoid primates (Hylobates, Pan, Homo) who engage in upright postures and locomotion. Patterns of integration in the hominoid cervical vertebrae correspond generally to those previously found in other mammals, suggesting that integration in this region is highly conserved, even among taxa that engage in novel positional behaviors. These integration patterns reflect underlying developmental as well as functional modules. The strong integration between vertebrae suggests that the functional morphology of the cervical vertebral column should be considered as a whole, rather than in individual vertebrae. Taxa that display highly derived morphologies in the cervical vertebrae are likely exploiting these integration patterns, rather than reorganizing them. Future work on vertebrates without cervical vertebral number constraints will further clarify the evolution of integration in this region.     

Variation among early Homo crania from Olduvai Gorge and the Koobi Fora region

Fossils recognized as early Homo were discovered first at Olduvai Gorge in 1959 and 1960. Teeth, skull parts and hand bones representing three individuals were found in Bed I, and more material followed from Bed I and lower Bed II. By 1964, L.S.B. Leakey, P.V. Tobias, and J.R. Napier were ready to name Homo habilis. But almost as soon as they had, there was confusion over the hypodigm of the new species. Tobias himself suggested that OH 13 resembles Homo erectus from Java, and he noted that OH 16 has teeth as large as those of Australopithecus. By the early 1970s, however, Tobias had put these thoughts behind him and returned to the opinion that all of the Olduvai remains are Homo habilis. At about this time, important discoveries began to flow from the Koobi Fora region in Kenya. To most observers, crania such as KNM-ER 1470 confirmed the presence of Homo in East Africa at an early date. Some of the other specimens were problematical. A.C. Walker and R.E. Leakey raised the possibility that larger skulls including KNM-ER 1470 differ significantly from smaller-brained, small-toothed individuals such as KNM-ER 1813. Other workers emphasized that there are differences of shape as well as size among the hominids from Koobi Fora. There is now substantial support for the view that in the Turkana and perhaps also in the Olduvai assemblages, there is more variation than would be expected among male and female conspecifics. One way to approach this question of sorting would be to compare all of the new fossils against the original material from Olduvai which was used to characterize Homo habilis in 1964. A problem is that the Olduvai remains are fragmentary, and none of them provides much information about vault form or facial structure. An alternative is to work first with the better crania, even if these are from other sites. I have elected to treat KNM-ER 1470 and KNM-ER 1813 as key individuals. Comparisons are based on discrete anatomy and measurements. Metric results are displayed with ratio diagrams, by which similarity in proportions for several skulls can be assessed in respect to a single specimen selected as a standard. Crania from Olduvai examined in this way are generally smaller than KNM-ER 1470, although OH 7 has a relatively long parietal. In the Koobi Fora assemblage, there is variation in brow thickness, frontal flattening and parietal shape relative to KNM-ER 1470. These comparisons are instructive, but vault proportions do not help much with the sorting process. Contrasts in the face are much more striking. Measurements treated in ratio diagrams show that both KNM-ER 1813 and OH 24 have relatively short faces with low cheek bones, small orbits and low nasal openings. Also, they display more projection of the midfacial region, just below the nose. This is not readily interpreted to be a female characteristic, since in most hominoid primates the females tend to have flatter lower faces than the males. The obvious size differences among these individuals have usually been interpreted as sex dimorphism, but, in fact, two taxa may be sampled at Olduvai and in the Turkana basin at the beginning of the Pleistocene. One large-brained group made up of KNM-ER 1470, several other Koobi Fora specimens, and probably OH 7, can be called Homo habilis. If these skulls go with femora such as KNM-ER 1481 and the KNM-ER3228 hip, then this species is close in postcranial anatomy to Homo erectus. The other taxon, including small-brained individuals such as KNM-ER 1813 and probably OH 13, seems also to be Homo rather than Australopithecus. If the OH 62 skeleton is part of this assemblage, then the small hominids have postcranial proportions unlike those of Homo erectus. However, it is too early to point unequivocally to one or the other of these groups as the ancestors of later humans. Both differ from Homo erectus in important ways, and both need to be better understood before we can map the earliest history of the Homo clade. © 1993 Wiley-Liss, Inc.     

Facial anatomy of Victoriapithecus and its relevance to the ancestral cranial morphology of old world monkeys and apes

Recently discovered Craniofacial fossils of the middle Miocene cercopithecoid Victoriapithecus are described. The frontal, zygomatic, maxilla, and premaxilla anatomy differ from the previously proposed colobine-like ancestral cercopithecoid morphotype in several significant respects. This morphotype was based on the assumption that features held in common by subordinate hominoid and cercopithecoid morphotypes (Colobinae and Hylobatidae) are primitive for Old World monkeys. Cranial similarities between Victoriapithecus, which represents the sister-group of both colobine and cercopithecone monkeys, and the shorter-snouted Cercopithecinae (Macaca and Cercopithecus) indicate that the last common ancestor of Old World monkeys possessed the following features: a narrow interorbital septum, moderately long snout, moderately long and anteriorly tapering premaxilla, large procumbent upper central incisors set anterior to and with longer roots than lateral incisors, moderately tall face below the orbits, teardrop-shaped nasal aperture of low height and moderate width, and probably long and narrow nasal bones. The Victoriapithecus cranium is also characterized by features not present in modern cercopithecids. These include a deep malar region of the zygomatic and the presence of a frontal trigon due to the occurrence of temporal lines that merge with supraorbital costae close to the midline of each orbit and converge anterior to bregma. These features are interpreted as primitive retentions from the basal catarrhine condition as indicated by the occurrence of these features among primitive catarrhines (Aegyptopithecus) and Miocene hominoids (Afropithecus). © 1993 Wiley-Liss, Inc.     

中国古人类进化连续性新辩

本文通过对一些形态特征的分析说明研究人类起源和进化应该注意的一些思维方法的问题,并且为多地区进化说增添了新的证据:1)中国更新世头骨共同具有的眼眶及其外侧下缘形状等特征在近代头骨中已有所改变,在考虑其意义时不应该忽略时间和基因交流起过的作用;2)中国更新世头骨的共同特征并不因为它们也可见于其他地区而丧失其意义,因为证明连续性的共同特征不需要是地区独有的;3)铲形门齿的结构在近代人中变弱,不削弱它作为连续进化证据的价值,这种弱化的现象是人类进化过程中形态纤巧化的一种表现;4)在辩论时不要对有关形态作不正确的观察和曲解对方的观点和论据;5)头骨正中矢状突隆、下颌圆枕、夹紧状鼻梁和第三臼齿先天性缺失等四项特征在近代非洲人中阙如,却存在于东亚近代人,本文的分析认为这种现象增强多地区进化说的说服力。     

Functional nasal morphology of chimaerid fishes

Holocephalans (chimaeras) are a group of marine fishes comprising three families: the Callorhinchidae (callorhinchid fishes), the Rhinochimaeridae (rhinochimaerid fishes) and the Chimaeridae (chimaerid fishes). We have used X‐ray microcomputed tomography and magnetic resonance imaging to characterise in detail the nasal anatomy of three species of chimaerid fishes: Chimaera monstrosa, C. phantasma and Hydrolagus colliei. We have shown that the nasal chamber of these three species is linked to the external environment by an incurrent channel and to the oral cavity by an excurrent channel via an oral groove. A protrusion of variable morphology is present on the medial wall of the incurrent channel in all three species, but is absent in members of the two other holocephalan families that we inspected. A third nasal channel, the lateral channel, functionally connects the incurrent nostril to the oral cavity, by‐passing the nasal chamber. From anatomical reconstructions, we have proposed a model for the circulation of water, and therefore the transport of odorant, in the chimaerid nasal region. In this model, water could flow through the nasal region via the nasal chamber or the lateral channel. In either case, the direction of flow could be reversed. Circulation through the entire nasal region is likely to be driven primarily by the respiratory pump. We have identified several anatomical features that may segregate, distribute, facilitate and regulate flow in the nasal region and have considered the consequences of flow reversal. The non‐sensory cilia lining the olfactory sensory channels appear to be mucus‐propelling, suggesting that these cilia have a common protective role in cartilaginous fishes (sharks, rays and chimaeras). The nasal region of chimaerid fishes shows at least two adaptations to a benthic lifestyle, and suggests good olfactory sensitivity, with secondary folding enhancing the hypothetical flat sensory surface area by up to 70%. J. Morphol. 274:987–1009, 2013. © 2013 Wiley Periodicals, Inc.     

Morphometric analysis of hominoid lower molars from Yuanmou of Yunnan Province, China

Shape analyses of cross-sectional mandibular molar morphology, using Euclidean Distance Matrix Analysis, were performed on 79 late Miocene hominoid lower molars from Yuanmou of Yunnan Province, China. These molars were compared to samples of chimpanzee, gorilla, orangutan,Lufengpithecus lufengensis, Sivapithecus, Australopithecus afarensis, and human mandibular molars. Our results indicate that the cross-sectional shape of Yuanmou hominoid lower molars is more similar to the great apes that to humans. There are few differences between the Yuanmou,L. lufengensis, andSivapithecus molars in cross-sectional morphology, demonstrating strong affinities between these three late Miocene hominoids. All three of the fossil samples show strong similarities to orangutans. From this, we conclude that these late Miocene hominoids are more closely related to orangutants than to either the African great apes or humans.     

Our ancestors' ancestor: Ouranopithecus is a greek link in human ancestry

Recent discoveries of the late Miocene hominoid Ouranopithecus shed new light on the evolution of hominids. These discoveries result from the strategy of the Allied armies during the First World War. In the midst of “the war to end all wars,” the North African soldiers of Camille Arambourg excavated the first mammalian fossils found in northern Greece, in the region of Macedonia, the country of Alexander the Great. On the tracks of these strange paleontological pioneers, a modern French and Greek team has unearthed a large hominoid primate, a missing link between fossilapes and primitive Australopithecus, which lived in southeastern Europe 9 to 10 million years ago. A reconstruction of Ouranopithecus and its surroundings gives us a rare glimpse into the world of the earliest hominids.     

从野店人骨论山东三组新石器时代居民的种族类型

<正> 我国人类学家颜訚先生,在研究山东大汶口和西夏侯两组新石器时代人骨特征时,认为这两组居民的体质特征属同一类型,即蒙古大人种中的玻里尼西亚类型。为了弄清楚新石器时代山东地区居民体质的种族类型,作者研究了由山东省博物馆提供野店遗址的新石器时代人骨,并参考颜訚的有关资料,对这个问题作进一步的讨论。     

Nacholapithecus and its importance for understanding hominoid evolution

Nacholapithecus kerioi is a large‐sized hominoid from the Aka Aiteputh Formation (15 Ma) in Nachola, northern Kenya. 1 While eight large‐sized hominoid species dating to the late Early to early Middle Miocene (17‐14 Ma) are known in Afro‐Arabia and western Eurasia, 2 - 6 the facial and postcranial anatomy of these apes is poorly known. However, much has been learned of the craniodental and postcranial anatomy of N. kerioi over the last ten years (A list of published specimens is available online, accompanying this article), and it plays a key role in our understanding of hominoid evolution in the Early to Middle Miocene of Africa and Eurasia. Importantly, it bears on the interpretation of the hominoid Morotopithecus bishopi from 20.6 my‐old Uganda. 7 - 10 In the article, we provide information on the anatomy and adaptations of N. kerioi as well as on the site of Nachola, and discuss how our current knowledge of N. kerioi can be incorporated into scenarios of hominoid evolution.     

Morphometric variation in the hominoid orbital aperture: a case study with implications for the use of variable characters in Miocene catarrhine systematics

Variable characters are ubiquitous in hominoid systematics and present a number of unique problems for phylogenetic analyses that include extinct taxa. As yet, however, few studies have quantified ranges of variation in complex morphometric characters within extant taxa and then used those data to assess the consistency with which discrete character states can be applied to poorly represented fossil species. In this study, ranges of intrageneric morphometric variation in the shape of the hominoid orbital aperture are estimated using exact randomization of average pairwise taxonomic distances (ATDs) derived from size-adjusted centroid, height-width, and elliptic Fourier (EF) variables. Using both centroid and height-width variables, 19 of the 21 possible ATDs between individuals representing seven extinct catarrhine taxa (Aegyptopithecus, Afropithecus, Ankarapithecus, Ouranopithecus, Paranthropus, Sivapithecus and Turkanapithecus) can be observed within a single extant hominoid subspecies, although generally with low probabilities. A resampling study is employed as a means for gauging the effect that this intrataxonomic variation may have on the consistency with which discrete orbital shape character states can be delimited given the small sample sizes available for most Miocene catarrhine taxa preserving this feature (i.e., n=1). For each type of morphometric variable, 100 cluster (UPGMA) analyses of pairwise ATDs are performed in which a single individual is randomly selected from each hominoid genus and analyzed alongside known extinct taxa; consensus trees are computed in order to obtain the frequencies with which different shape clusters appeared in each of the three analyses. The two major clusters appearing most frequently in all three consensus trees are found in only 57% (centroid variables), 49% (height-width variables), and 36% (EF variables) of these trees. If ranges of variation within represented extinct taxa could also be estimated, these frequencies would certainly be far lower. Hominoids clearly exhibit considerable intrageneric, intraspecific, and even intrasubspecific variation in orbit shape, and substantial morphometric overlap exists between taxa; consequently, discrete character states delimiting these patterns of continuous variation are likely to be highly unreliable in phylogenetic analyses of living and extinct species, particularly as the number of terminal taxa increases. Morphological phylogenetic studies of extant catarrhines that assess the effect of different methods (e.g., use of objective a priori weighting or frequency coding of variable characters, inclusion vs. exclusion of variable characters, use of specific vs. supraspecific terminal taxa) on phylogenetic accuracy may help to improve the techniques that systematists employ to make phylogenetic inferences about extinct taxa.     

Major features in the evolution of early hominoid locomotion

Evolution of hominoid locomotion is a traditional topic in primate evolution. Views have changed during the last decade because a number of crucial differences between early and advanced hominoid morphologies have been demonstrated. Increasing evidence on primate behaviour and ecology show that any direct analogies between living and fossil hominoids must be made extremely carefully. The necessity of synthesizing data on primate behaviour, locomotion, morphology and ecology and simultaneously defining the framework in which the data should be interpreted are explained. Results of our studies of ontogeny of locomotor and behavioural patterns (LBP) are presented that could help identify the main features of early hominoid locomotor patterns (LP) and the mechanisms of their changes. The early hominoid LP was different from those of pronograde monkeys and specialized antipronograde living apes. Some similar features could be expected between early hominoid LP and the LP of ceboid monkeys. Analogous mechanisms of change of LBP exist in all groups of living higher primates. Crucial early mechanisms of change are the ontogenetic shifts in LBP connected with ethoecological changes. Analysis of fossil evidence has shown that Miocene hominoids differ morphologically from any group of living primates. Certain features present in Miocene hominoids could be found in Atelinae and living Asian apes but they are limited to some functional regions of the postcrania only. Consequently the early hominoid general LP can not be strictly analogous either to that of any monkey group or to the LP of apes. We suppose that certain pronograde adaptations, such as climbing, bipedality, limited suspensory activity and sitting constituted the main part of their LP.