Mugharet el'Aliya: Affinities of an enigmatic north African Aterian maxillary fragment

Objectives

This study uses a virtual framework to examine the left maxillary fragment of the juvenile fossil from Mugharet el'Aliya, Morocco, found in association with an Aterian lithic industry. Previously, this fossil had been ascribed to modern humans or the Neanderthal lineage based on its “archaic”/“Neanderthal-like” features and apparent large size. Here, we conducted a novel 3D shape comparative analysis of the maxillary fragment to clarify its taxonomic affinities with regard to its size and ontogeny.

Materials and Methods

Eighty Computed Tomography and surface scans representing ontogenetic samples of Homo sapiens and Homo neanderthalensis were used to capture species-specific differences. The toolkit of geometric morphometrics in combination with surface registration and an elastic iterative closest point algorithm were used to create a dataset of meshes with an identical number of corresponding vertices for the maxillae. Multivariate statistics were applied to Procrustes superimposed coordinates derived from the vertices of this dataset.

Results

Our analysis showed affinities of the Mugharet el'Aliya individual with our H. sapiens sample, especially with a subadult individual from Qafzeh. No size-independent affinities with Neanderthals of comparable dental age could be identified.

Discussion

Our results add to the evidence connecting fossils from western Asia, especially Qafzeh and Skhul, and the North African Aterian. Furthermore, Mugharet el'Aliya adds to our knowledge of the ontogenetic development of adult morphology that is frequently used to characterize hominin groups, for example, Neanderthals and modern humans.     

Zuttiyeh face: A view from the east

We analyze the phylogenetic position of the frontofacial fragment from Zuttiyeh, Israel. This specimen is dated to the Middle Pleistocene (the latest estimate is between 250 and 350 kyr) and is associated with the Acheulo-Yabrudian, which makes it the oldest cranium from the region. It has been previously regarded as a Neandertal, and early “anatomically modern Homo sapiens,” and a generalized specimen ancestral to both. These different phylogenetic interpretations of its features have a historic basis but in our view also result from a confusion of grade and intraspecies clade as valid sources of variation. We show here that generally the differences that distinguish Zuttiyeh from Neandertals are similarities it shares with the Zhoukoudian remains. These similarities involve a unique combination of features, and suggest the possibility of an ancestral relationship. It is less likely that Middle Pleistocene remains from Europe or sub-Saharan Africa are uniquely or significantly ancestral to Zuttiyeh. An accurate understanding of the relationship between populations of eastern and western Asia is important for resolving the more general questions surrounding the position of the Upper Pleistocene Levant populations in human evolution, including (1) whether there are significantly different contemporary Mousterian populations in the Upper Pleistocene, (2) whether Neandertals are clearly intrusive in the region, and (3) whether there is an early appearance of (what many workers call) “anatomically modern Homo sapiens.” The hypothesis of a recent unique African ancestry for all modern humans is disproved by our study, which shows Asia as a significant source area for at least some living populations. © 1993 Wiley-Liss, Inc.     

Occipital bunning among later pleistocene hominids

Occipital bunning is a posterior projection of the occipital squama, which occurs in varying frequencies in samples of archaic Homo sapiens, Upper Pleistocene anatomically modern humans, and recent humans. It can be best interpreted as a product of the timing of posterior cerebral growth relative to the growth of the cranial vault bones. It is not a feature that was unique to the Neandertals.     

Neandertals and moderns mixed,and it matters

Twenty‐five years ago, the Middle‐to‐Upper Paleolithic transition in Europe could be represented as a straightforward process subsuming both the emergence of symbolic behavior and the replacement of Neandertals by modern humans. The Aurignacian was a proxy for the latter, during which enhanced cognitive capabilities explained ornaments and art. The few instances of Neandertal symbolism were deemed to long postdate contact and dismissed as “imitation without understanding,” if not geological contamination. Such views were strengthened by the recent finding that, in southern Africa, several features of the European Upper Paleolithic, including bone tools, ornaments, and microliths, emerged much earlier. Coupled with genetic suggestions of a recent African origin for extant humans, fossil discoveries bridging the transition between “archaics” and “moderns” in the realm of anatomy (Omo‐Kibish, Herto) seemingly closed the case. Over the last decade, however, taphonomic critiques of the archeology of the transition have made it clear that, in Europe, fully symbolic sapiens behavior predates both the Aurignacian and moderns. And, in line with evidence from the nuclear genome rejecting strict replacement models based on mtDNA alone, the small number of early modern specimens that passed the test of direct dating present archaic features unknown in the African lineage, suggesting admixture at the time of contact. In the realm of culture, the archeological evidence also supports a Neandertal contribution to Europe's earliest modern human societies, which feature personal ornaments completely unknown before immigration and are characteristic of such Neandertal‐associated archeological entities as the Châtelperronian and the Uluzzian. The chronometric data suggest that, north of the Ebro divide, the entire interaction process may have been resolved within the millennium centered around 42,000 calendar years ago. Such a rapid absorption of the Neandertals is consistent with the size imbalance between the two gene reservoirs and further supports significant levels of admixture.     

Early and Middle Pleistocene hominins from Atapuerca (Spain) show differences in dental developmental patterns

The Bayesian statistical approach considers teeth as forming a developmental module, as opposed to a tooth-by-tooth analysis. This approach has been employed to analyze Upper Pleistocene hominins, including Neandertals and some anatomically modern humans, but never earlier populations. Here, we show its application on five hominins from the TD6.2 level of the Gran Dolina site (Homo antecessor, Early Pleistocene) and the Sima de los Huesos site (Middle Pleistocene) of the Sierra de Atapuerca (Burgos, northern Spain). Our results show an advanced development of the third molars in both populations with respect to modern Homo sapiens. In addition, the Sima de los Huesos hominins differ from H. sapiens and H. antecessor in the relatively advanced development of their second molar. The relative mineralization of I1/M1 in H. antecessor appears to be similar to that of modern humans, as opposed to that of Neandertals, which appear to be unique. These observations, combined with reduced enamel formation times and the advanced development of the third molars, appear to indicate a shorter ontogenetic period in the hominins from Gran Dolina and Sima de los Huesos in comparison to modern human average.     

Late archaic and modern Homo sapiens from Europe, Africa, and Southwest Asia: Craniometric comparisons and phylogenetic implications

The craniometric affinities among Neandertals. Upper Palcolithic Europeans, early anatomically modern Southwest Asians, and archaic and modern Africans are investigated using univariate and multivariate methods. For the first time, it is possible to analyse the North African finds Dar-es-Soltane 5, Nazlet Khater, and Wadi Kubbaniya. It was not possible to include the Neandertals from Central Europe due to their poor state of preservation. The results point to, first, a basic distinction between Neandertals on the one hand and modern humans from all geographic regions on the other, and, secondly, to great similarities between modern African and European populations. Late archaic sapiens specimens from Africa were more similar to Upper Paleolithic Europeans than were the Neandertals. The results do not support the hypothesis that a regional evolution giving rise to modern humans took place in Europe. The results are, however, consistent with the hypothesis that modern populations originated in Africa and spread to Europe from there.     

Absolute and relative endocranial size in Neandertals and later Pleistocene Homo

Eurasian Neandertals encompass the entire observed range of recent and fossil Homo sapiens in absolute, but not relative endocranial volume, and Neandertals attest an average EQ significantly lower than their Upper Pleistocene successors. While the cognitive, social, and evolutionary implications of this phenomenon have been emphasised, the statistical basis of a mean inference of EQ in the Neandertal hypodigm has not been appropriately demonstrated. A demonstrable male bias in the available postcranial, not cranial, series has skewed perceptions of Neandertal brain-to-body size scaling towards a rejection of the null hypothesis. A simple resolution to this problem is a concise assessment of paired associated covariates against a suitable recent human comparator series. Permutations of Fisher's z and Student's t statistics are valid metrics in tests of significance in single datum hypotheses.     

Upper pleistocene human remains from Vindija cave,Croatia, Yugoslavia

Human remains excavated from Vindija cave include a large although fragmentary sample of late Mousterian-associated specimens and a few additional individuals from the overlying early Upper Paleolithic levels. The Mousterian-associated sample is similar to European Neandertals from other regions. Compared with earlier Neandertals from south central Europe, this sample evinces evolutionary trends in the direction of Upper Paleolithic Europeans. Compared with the western European Neandertals, the same trends can be demonstrated, although the magnitude of difference is less, and there is a potential for confusing temporal with regional sources of variation. The early Upper Paleolithic-associated sample cannot be distinguished from the Mousterian-associated hominids. We believe that this site provides support for Hrdli?ka's “Neandertal phase” of human evolution, as it was originally applied in Europe.     

Lower limb bone structure of Middle Pleistocene hominins from the Caune de l’Arago (Tautavel,France): Evolutionary and functional comparison with the penecontemporaneous hominins of Sima de los Huesos (Atapuerca,Spain)

The Caune de l’Arago (Arago) and Sima de los Huesos (Sima) human bones from the European Middle Pleistocene are penecontemporaneous, although the Sima hominins are closely related to Neandertal, and Arago hominins present more archaic features. In previous and in press studies, the cross-sectional geometric properties (CSG) of lower limb bones of Arago and Sima have been studied separately without comparative analyses. Here, in order to bridge this gap, we use the same criteria for both samples to highlight evolutionary affinities and to compare their level and pattern of mobility. This study focuses on the femur, fibula and tibia from Arago and Sima with references to fossils from the sites of Trinil, Zhoukoudian and Lazaret, and ancient and recent Homo sapiens (including athletes and non-athletes). We analyze the cross-sectional areas, biomechanical bone “shape” indices (Ix/Iy, Imax/Imin) and pattern of cortical bone distribution. All lower limb bones from Arago have noticeably high to very high relative cortical areas and low to very low medullary areas. The overall femoral pattern in Arago, like Sima, is similar to that of Middle Pleistocene hominins (e.g., low femoral shape indices, Ix/Iy) and Neandertals (e.g., large cross-sectional size). However, the femoral midshaft in Sima presents prominent posteromedial cortical thickening, as a result of a spiral cortical reinforcement along the medial side of the diaphysis. This characteristic is specific to Neandertal and some Middle Pleistocene hominins. In contrast, the midshaft femoral pattern in Arago is close to that of some Homo erectus. We also note that the femoral cross-sectional size and relative cortical area in Arago differ drastically to the small size and low relative cortical area of Lazaret and Trinil hominins. The very high shape index at midshaft (i.e., high Imax/Imin) of the Arago tibia is observed in ancient H. sapiens and runners; the tibial posterior “pilaster” is found in Neandertals and ancient H. sapiens; and the flat or convex tibial faces are similar to Neandertals. Furthermore, the Arago fibulas show marked fibular posterolateral cortical reinforcement with low anteroposterior strengthening. These leg features (tibia, fibula) are also found in some Sima hominins (but not in all individuals). Consequently, this study confirms the presence of archaic features in Arago and the close evolutionary relationship between Sima and Neandertal. This proposition is mainly based on the femoral midshaft pattern influenced by the pelvofemoral complex, considered to be substantially genetically controlled. The leg functional analysis highlights a high level of mobility and travelling in uneven terrains or in mountainous areas in Arago, consistent with known environments and hunting practices. Previously, an analogous hypothesis was proposed put forward for Sima hominins.     

The medial pterygoid tubercle in the Atapuerca Early and Middle Pleistocene mandibles: Evolutionary implications

Numerous studies have attempted to identify the presence of uniquely derived (autoapomorphic) Neandertal features. Here, we deal with the medial pterygoid tubercle (MTP), which is usually present on the internal face of the ascending ramus of Neandertal specimens. Our study stems from the identification of a hypertrophied tubercle in ATD6‐96, an Early Pleistocene mandible recovered from the TD6 level of the Atapuerca‐Gran Dolina site and attributed to Homo antecessor. Our review of the literature and study of numerous original fossil specimens and high quality replicas confirm that the MTP occurs at a high frequency in Neandertals (ca. 89%) and is also present in over half (ca. 55%) of the Middle Pleistocene Sima de los Huesos (SH) hominins. In contrast, it is generally absent or minimally developed in other extinct hominins, but can be found in variable frequencies (<ca. 25%) in Pleistocene and recent H. sapiens samples. The presence of this feature in ATD6‐96 joins other traits shared by H. antecessor, the SH hominins and Neandertals. Since the TD6 hominins have been attributed either to MIS 21 or to MIS 25, it seems that a suite of assumed derived Neandertal features appeared in the Early Pleistocene, and they should be interpreted as synapomorphies shared among different taxa. We suggest that H. antecessor, the SH hominins and Neandertals shared a common ancestor in which these features appeared during the Early Pleistocene. The presence of the MTP in taxa other than H. neanderthalensis precludes this feature from being a Neandertal autapomorphy. Am J Phys Anthropol 156:102–109, 2015 © 2014 Wiley Periodicals, Inc.     

Calvarial shape variation among Middle Pleistocene hominins: An application of surface scanning in palaeoanthropology

The increasing availability of 3D data and tools offers new analytical perspectives in palaeoanthropology, such as the quantitative testing of opposing phylogenetic scenarios. Using optical surface scan data and geometric morphometric techniques, this study explores calvarial shape variation in the “Middle Pleistocene muddle”. The morphological variability between H. erectus on the one hand and H. sapiens/neanderthalensis on the other has long remained obscure: opposing views have attributed the known specimens to any of the three species and possibly one or two more. A large number of landmarks and semilandmarks was extracted from the braincase and the face, in order to quantify the calvarial shape differences among species and key fossils. The results are incompatible with the hypothesis that H. rhodesiensis is the exclusive ancestor of H. sapiens, and offer only weak support for an exclusively European ancestor of Neandertals.     

Postcranial evidence of cold adaptation in European Neandertals

The low brachial and crural indices of the European Neandertals have long been considered indicative of cold adaptation. Recent work has documented lower limb/trunk ratios and deeper chests (anterior-posterior diameter) in European Neandertals than among their successors. The present study uses variables reflective of limb length, body mass and trunk height, and compares European Neandertals to 15 globally diverse recent human samples (1 “Eskimo,” 3 North African, 4 sub-Saharan African and 7 European). Bivariate plots, as well as principal components analysis plots of log shape-transformed data, indicate that European Neandertals had an overall body shape that falls at the extreme end of modern higher latitude groups' range of variation. Cluster analysis (minimum spanning tree on a principal coordinates plot) indicates that the Neandertals are closest in body shape to modern “Eskimos,” but even in this dendrogram, they are joined to the “Eskimo” via a long branch. In fact, it appears that European Neandertals were “hyperpolar” in body shape, likely due to two factors: 1) the extremely cold temperatures of glacial Europe and 2) less effective cultural buffering against cold stress. Am J Phys Anthropol 104:245–258, 1997. © 1997 Wiley-Liss, Inc.     

The absolute dating of Upper Pleistocene subSaharan fossil hominids and their place in human evolution

In the evolution of anatomically modern man and his subspecies most specialists have concentrated on investigating geographical areas other than Africa as the possible area of origin.In this study 20 fossil hominids and associated faunal remains from South and East Africa were dated by microanalysis, radiocarbon, and amino-acid dating in order to see whether modern man appears later, was sympatric, or even predated Neandertal man.These dates indicate that anatomically modern man occurs sympatrically and possibly even predates the Rhodesian group of Neandertals in Africa. Modern man might also be contemporary to and possibly even predate the occurrence of Neandertal in Europe.This would indicate that modern man did not evolve from but possibly gave rise to the Neandertals as off-shoots.Two possibilities for the evolution of modern man are suggested. First, that Homo sapiens capensis evolved about 90,000 to 100,000 years ago from possibly Homo erectus by way of a “basic” Homo sapiens and later gave rise to Homo sapiens rhodesiensis, Homo sapiens afer, and possibly Homo sapiens palestinus around 50,000 years ago with Homo neanderthalensis and Homo sapiens capensis evolving separately from Homo erectus. In this case Homo neanderthalensis would be a different species from Homo sapiens which includes Homo sapiens capensis, Homo sapiens rhodesiensis, Homo sapiens afer, and possibly Homo sapiens palestinus.Secondly, Homo sapiens capensis evolved by way of a “basic” Homo sapiens with Homo sapiens rhodesiensis and Homo sapiens palestinus branching off from Homo sapiens capensis around 50,000 years ago. Before that, around 90,000 to 100,000 years ago Homo sapiens capensis evolved first and was then followed by Homo sapiens neanderthalensis from a “basic” Homo sapiens stock, but diverged. This means, all Neandertals, Homo sapiens capensis, Homo sapiens sapiens and Homo sapiens afer can be considered as subspecies of Homo sapiens.The author favors the first scheme since on relative dating grounds the existence of Neandertal man in Europe before the earliest date of Homo sapiens capensis and a “basic” Homo sapiens seems to be fairly well documented. Irrespective of either one of these possibilities, modern man evolved in Africa and seems to have migrated into Europe and other parts of the world.New absolute dating techniques are mentioned in detail like the new radiocarbon-collagen method and amino acid dating.     

Geometric variation of the frontal squama in the genus homo: Frontal bulging and the origin of modern human morphology

The majority of studies of frontal bone morphology in paleoanthropology have analyzed the frontal squama and the browridge as a single unit, mixing information from different functional elements. Taking into account that the bulging of the frontal bone is often described as a species‐specific trait of Homo sapiens, in this article we analyze variation in the midsagittal profile of the genus Homo, focusing on the frontal squama alone, using landmark‐based superimpositions and principal components analysis. Our results demonstrate that anatomically modern humans are definitely separated from extinct human taxa on the basis of frontal bulging. However, there is minor overlap among these groups, indicating that it is necessary to exercise caution when using this trait alone to make taxonomic inferences on individual specimens. Early modern humans do not show differences with recent modern humans, and “transitional” individuals such as Jebel Irhoud 1, Maba, and Florisbad, show modern‐like frontal squama morphology. The bulging of the frontal squama in modern humans may represent a structural consequence of more general cranial changes, or it could be a response to changes in the morphology of the underlying prefrontal brain elements. A subtle difference between Neandertals and the Afro‐European Middle Pleistocene Homo sample is associated with flattening at bregma in the former group, a result that merits further investigation. Am J Phys Anthropol, 2013. © 2013 Wiley Periodicals, Inc     

Neanderthal Skeletal Structure and the Place of Homo neanderthalensis in European Hominid Phylogeny

Although the debate rages on over whether the Neanderthals merit their own species status or should be viewed as an odd variant of Homo sapiens, recent evidence has accumulated that overwhelmingly supports the former interpretation. Among this evidence is a recent full-body skeletal reconstruction that not only highlights the extreme differences between the highly apomorphic H. sapiens and H. neanderthalensis in the construction of the thorax and pelvic girdle, but strongly suggests significant gait differences between the two species that add to the probability that the two kinds of hominid would not have recognized each other as breeding partners. This is hardly surprising since the two species possessed a relatively remote common ancestry, and it is indeed suggested here that Homo neanderthalensis was merely one species embedded within a diverse and endemic middle Pleistocene European hominid radiation. Clearly more than one lineage of hominids simultaneously occupied Europe during the middle Pleistocene.     

Right‐handed fossil humans

Fossil hominids often processed material held between their upper and lower teeth. Pulling with one hand and cutting with the other, they occasionally left impact cut marks on the lip (labial) surface of their incisors and canines. From these actions, it possible to determine the dominant hand used. The frequency of these oblique striations in an array of fossil hominins documents the typically modern pattern of 9 right‐ to 1 left‐hander. This ratio among living Homo sapiens differs from that among chimpanzees and bonobos and more distant primate relatives. Together, all studies of living people affirm that dominant right‐handedness is a uniquely modern human trait. The same pattern extends deep into our past. Thus far, the majority of inferred right‐handed fossils come from Europe, but a single maxilla from a Homo habilis, OH‐65, shows a predominance of right oblique scratches, thus extending right‐handedness into the early Pleistocene of Africa. Other studies show right‐handedness in more recent African, Chinese, and Levantine fossils, but the sample compiled for non‐European fossil specimens remains small. Fossil specimens from Sima del los Huesos and a variety of European Neandertal sites are predominately right‐handed. We argue the 9:1 handedness ratio in Neandertals and the earlier inhabitants of Europe constitutes evidence for a modern pattern of handedness well before the appearance of modern Homo sapiens.     

Brief communication: Investigation of the semicircular canal variation in the Krapina Neandertals

Previous studies comparing bony labyrinth morphology in geographically‐dispersed samples of Neandertals and modern Homo sapiens (H. sapiens) showed that Neandertals generally have smaller semicircular canals than modern H. sapiens (Hublin et al., 1996 ; Spoor et al., 2003 ; Glantz et al., 2008 ). Here we analyze the morphology of a single group of Neandertal specimens from one locale, the Krapina site, to determine the intraspecific variation in Neandertal semicircular canal sizes. Dimensions of the semicircular canals were collected from computed tomography scans of nine temporal bones. With the rare exception, the dimensions of the semicircular canals in the Krapina sample are similar to those previously reported across a geographically‐dispersed sample of Neandertals, further supporting previous studies that suggest low levels of variation in the semicircular canals for Neandertals. Am J Phys Anthropol 154:302–306, 2014. © 2014 Wiley Periodicals, Inc.     

New Neandertal remains from Cova Negra (Valencia, Spain)

New Neandertal fossils from the Mousterian site of Cova Negra in the Valencia region of Spain are described, and a comprehensive study of the entire human fossil sample is provided. The new specimens significantly augment the sample of human remains from this site and make Cova Negra one of the richest human paleontological sites on the Iberian Peninsula. The new specimens include cranial and postcranial elements from immature individuals and provide an opportunity to study the ontogenetic appearance of adult Neandertal characteristics in this Pleistocene population. Children younger than 10 years of age constitute four of the seven minimum number of individuals in the sample, and this relative abundance of children at Cova Negra is similar that in to other Neandertal sites in Europe and southwest Asia. The recognition of diagnostic Neandertal features in several of the specimens, as well as their western European context and late Pleistocene age, suggests that all the human remains from Cova Negra represent Neandertals. The archaeological evidence from Cova Negra indicates sporadic, short-term occupations of the site, suggesting a high degree of mobility among Neandertals.     

The ATD6-5 mandibular specimen from Gran Dolina (Atapuerca, Spain). Morphological study and phylogenetic implications.

Metric and shape features of the Lower Pleistocene mandibular specimen ATD605 from the level 6 of Gran Dolina site (Atapuerca, Spain) are compared with a large sample of fossil hominid mandibles. The analysis shows that ATD6-5 displays a generalized morphology largely shared with both African and European Lower and Middle Pleistocene samples. However, distinctive African traits, such as corpus robustness and strong alveolar prominence, are absent in the Gran Dolina specimen. At the same time, none of the apomorphic features that characterize Middle and early Upper Pleistocene European hominids can be recognized in ATD6-5. Finally, the Gran Dolina specimen displays a remarkable position of the mylohyoid groove, only comparable to that found in immature specimens of Homo ergaster, and very rarely in adult H. sapiens. The morphology of ATD6-5 supports the hypothesis of an African origin for the first Europeans with subsequent phylogenetic continuity with Middle Pleistocene populations in Europe. These findings are consistent with H. antecessor being the last common ancestor of Neandertals and H. sapiens.     

Homo erectus—who,when and where: A survey

The state of information bearing on Homo erectus as developed since about 1960 is surveyed, with the resulting effects on problems. Definitions of H. erectus still rest on the Far Eastern samples (Chou-k'ou-tien/Java), and thus relate to late Lower to middle Middle Pleistocene material. Numerous important individual finds, however, have expanded the total: extension of the early and very early Sangiran material; very early to later in Africa, and relatively late in Europe. Datings remain uncertain or controversial within broad limits, but with some important successes and revisions. Discussion by authors of problems concerns degree of divergence among H. erectus populations and rate of evolutionary change; both appear relatively slight, but the data are inadequate for much present judgment. The apparent zone of transition to more advanced morphology (H. sapiens, sensu lato) by the late Middle Pleistocene better reflects signs of regional divergence. Some writers—not all—believe that even the earliest European fossils known (e.g., Petralona) had already advanced to a H. sapiens basic level, with later change in the direction of Neanderthals. A separate African phylum, from OH 9, is also suggested; recent Chinese finds may provide a third different post-erectus population before the Upper Pleistocene. Taxonomic expression of all this gives some problems.