Human hyoid bones from the middle Pleistocene site of the Sima de los Huesos (Sierra de Atapuerca, Spain)

This study describes and compares two hyoid bones from the middle Pleistocene site of the Sima de los Huesos in the Sierra de Atapuerca (Spain). The Atapuerca SH hyoids are humanlike in both their morphology and dimensions, and they clearly differ from the hyoid bones of chimpanzees and Australopithecus afarensis. Their comparison with the Neandertal specimens Kebara 2 and SDR-034 makes it possible to begin to approach the question of temporal variation and sexual dimorphism in this bone in fossil humans. The results presented here show that the degree of metric and anatomical variation in the fossil sample was similar in magnitude and kind to living humans. Modern hyoid morphology was present by at least 530 kya and appears to represent a shared derived feature of the modern human and Neandertal evolutionary lineages inherited from their last common ancestor.     

Reconstitution 3D par Computerized-tomography (CT) et endocrâne virtuel du crâne 5 du site de la Sima de Los Huesos (Atapuerca)

The 3d Ct reconstruction and virtual brain endocast of Cranium 5 from the site of “La Sima de los Huesos” (Atapuerca), allows us to get new information to increase the study and knowledge of Homo heidelbergensis population, and to compare this specimen with others in the fossil record, in order to understand the evolutionary process of the brain, focusing on the middle Pleistocene period. Furthermore, we can observe the changes this species (Homo heidelbergensis) has undergone, at least in Sima de los Huesos population making comparative studies with African and Asian middle Pleistocene specimens. We have used the new data to compare European Homo heidelbergensis represented by SH5 with Kabwe, a controversial specimen considered by some authors like the African Homo heidelbergensis representative, in order to establish the similarities and differences between both specimens.     

Human talus bones from the Middle Pleistocene site of Sima de los Huesos (Sierra de Atapuerca,Burgos, Spain)

Here we present and describe comparatively 25 talus bones from the Middle Pleistocene site of the Sima de los Huesos (SH) (Sierra de Atapuerca, Burgos, Spain). These tali belong to 14 individuals (11 adult and three immature). Although variation among Middle and Late Pleistocene tali tends to be subtle, this study has identified unique morphological characteristics of the SH tali. They are vertically shorter than those of Late Pleistocene Homo sapiens, and show a shorter head and a broader lateral malleolar facet than all of the samples. Moreover, a few shared characters with Neanderthals are consistent with the hypothesis that the SH population and Neanderthals are sister groups. These shared characters are a broad lateral malleolar facet, a trochlear height intermediate between modern humans and Late Pleistocene H. sapiens, and a short middle calcaneal facet. It has been possible to propose sex assignment for the SH tali based on their size. Stature estimates based on these fossils give a mean stature of 174.4 cm for males and 161.9 cm for females, similar to that obtained based on the long bones from this same site.     

Les matières premières,la technologie lithique et les stratégies d’occupation dans le site du Pléistocène moyen de Covacha de los Zarpazos (gisement de Galería,Sierra de Atapuerca,Espagne)

Variability is one of the most debated topics in lithic technology studies. For the Middle Pleistocene period, this debate has specifically focused on the significance of large cutting tools such as handaxes and cleavers. This paper presents the stone tool assemblage from Covacha de los Zarpazos site, included in the Galería complex at Sierra de Atapuerca (Burgos, Spain). We analyse the management of lithic raw materials, the reduction sequences identified, and the morphological variation in the shape of large cutting tools. The results show that raw materials play an important role in the final variability of tool shape, although they do not represent any real constraint. However, what determines the main variability of a whole lithic assemblage is the occupation strategy and the specific activities carried out in a given site.     

Non-masticatory uses of anterior teeth of Sima de los Huesos individuals (Sierra de Atapuerca, Spain)

In this study we examine the labial and occlusal surfaces of incisors and canines of hominins recovered from the Sima de los Huesos (SH), middle Pleistocene site, in order to establish the possible extra-masticatory use of anterior teeth. We have compared the microwear of these fossils with microwear from the anterior teeth of Australian Aborigines, a population characterized by ethnographic evidence of the use of their teeth as a third hand. These two samples of teeth were microscopically analyzed using Scanning Electron Microscopy (SEM). Our results support the “cultural” origin of microwear observed on fossil teeth: we conclude that the SH hominins used their anterior teeth as a “third hand” for para- or extra-masticatory activities.     

Étude analytique d’une clavicule complète de subadulte d’Homo antecessor (site de Gran Dolina, Sierra d’Atapuerca, Burgos, Espagne)

This study reports on the skeletal remains of an infant clavicle - specimen ATD6-37 - belonging to the Homo antecessor species, unearthed at Lower Pleistocene level TD6 of the Gran Dolina site (Sierra de Atapuerca). Studied alongside a further adult specimen - ATD6-50 -, they provide us with significant information on two key paleobiological aspects of these early humans: body shape and development. Based on the analytical results, the paper proposes a more accurate proportional method for determining age at death is applied to the fossilized infant clavicle under study. It goes on to hypothesize on postcranial growth and body shape and discusses morphological patterns and age at death of these early humans through comparisons with a wide range of infant dental samples and clavicular specimens in early and modern humans.     

Metric and morphological study of the upper cervical spine from the Sima de los Huesos site (Sierra de Atapuerca, Burgos, Spain)

In this article, the upper cervical spine remains recovered from the Sima de los Huesos (SH) middle Pleistocene site in the Sierra de Atapuerca (Burgos, Spain) are described and analyzed. To date, this site has yielded more than 5000 human fossils belonging to a minimum of 28 individuals of the species Homo heidelbergensis. At least eleven individuals are represented by the upper cervical (C1 and C2) specimens: six adults and five subadults, one of which could represent an adolescent individual. The most complete adult vertebrae (three atlases and three axes) are described, measured, and compared with other fossil hominins and modern humans. These six specimens are associated with one another and represent three individuals. In addition, one of these sets of cervical vertebrae is associated with Cranium 5 (Individual XXI) from the site. The metric analysis demonstrates that the Sima de los Huesos atlases and axes are metrically more similar to Neandertals than to our modern human comparative sample. The SH atlases share with Neandertals a sagittally elongated canal. The most remarkable feature of the SH (and Neandertal) axes is that they are craniocaudally low and mediolaterally wide compared to our modern male sample. Morphologically, the SH sample shares with Neandertals a higher frequency of caudally projected anterior atlas arch, which could reflect greater development of the longus colli muscle. In other features, such as the frequency of weakly developed tubercles for the attachment of the transverse ligament of the atlas, the Sima de los Huesos fossils show intermediate frequencies between our modern comparative samples and the Neandertals, which could represent the primitive condition. Our results are consistent with the previous phylogenetic interpretation of H. heidelbergensis as an exclusively European species, ancestral only to H. neanderthalensis.     

Nonocclusal dental microwear analysis of 300,000-year-old Homo heilderbergensis teeth from Sima de los Huesos (Sierra de Atapuerca, Spain)

Casts of nonocclusal enamel surfaces of 190 teeth from the Middle Pleistocene site of Sima de los Huesos have been micrographed by scanning electron microscopy. Microscopic analyses of striation density and length by orientation show distinct patterns of intrapopulation variability. Significant differences in the number and length of the striations by orientation are found between maxillary and mandibular teeth. This probably reflects differences in the mechanical forces involved in the process of chewing food. Significant differences are present between isolated and in situ teeth that could be caused by postdepositional processes differentially affecting the isolated teeth. In addition, a distinct and very unusual striation pattern is observed in a sample of teeth that can be explained only by a strong nondietary, most probably postmortem abrasion of the enamel surfaces. These teeth have a very high density of scratches, shorter in length than those found on other teeth, that are not indicative of dietary habits. No known depositional process may account for the presence of such postmortem wear since heavy transportation of materials within the clayish sediments has been discarded for the site. Despite this, a characteristic dietary striation pattern can be observed in most of the teeth analyzed. Most likely the diet of the Homo heidelbergensis hominids from Sima de los Huesos was highly abrasive, probably with a large dependence on hard, poorly processed plant foods, such as roots, stems, and seeds. A highly significant sex-related difference in the striation pattern can also be observed in the teeth analyzed, suggesting a differential consistency in the foods eaten by females and males.     

Pattern of dental development in Hominid XVIII from the Middle Pleistocene Atapuerca-Sima de los Huesos site (Spain)

. We describe the pattern of dental development of Hominid XVIII from the Middle Pleistocene Sima de los Huesos (SH) site of the Sierra de Atapuerca (Burgos, Spain). As expected, this pattern is similar to that of modern humans. A delay of development of the lower and upper canines was observed. In contrast, the relative advanced development of the lower second molars and, especially, the upper and lower third molars is noteworthy. This latter feature seems to be common in Pleistocene hominids, and suggests that the pattern of dental development evolved in the genus Homo during the Pleistocene. In European Middle Pleistocene hominids, this pattern probably was facilitated by the extra space available in the mandible and maxilla for developing teeth.     

Right handedness of Homo heidelbergensis from Sima de los Huesos (Atapuerca, Spain) 500,000 years ago

Handedness is a product of brain specialization, which in turn seems to be responsible for the higher cognitive capabilities of humans, such as language and technology. Handedness in living humans is well established and shows the highest degree of manual specialization. Studies on hand laterality in nonhuman primates, particularly in chimpanzees, remain a matter of controversy as results tend to vary depending on factors such as the tasks performed and the environment in which the individuals live. Studies in several disciplines have attempted to determine where in the course of human evolution handedness established itself, with evidence collected from sources such as paleoneurological analyses, stone tool flaking, zooarchaeological studies and dental wear analyses, the last one of which have proven the most reliable source of information. Here we report an experimental and paleoanthropological study on hand laterality of a sample of 28 hominids from Sima de los Huesos (Atapuerca, Spain), dated at about 500,000 years ago, and compare our results with dental microwear analysis in other fossil samples such as that from Krapina (Croatia), as well as modern traditional societies. Our results indicate that European Middle Pleistocene Homo heidelbergensis was already as right-handed as modern populations.     

Stature estimation from complete long bones in the Middle Pleistocene humans from the Sima de los Huesos, Sierra de Atapuerca (Spain)

Systematic excavations at the site of the Sima de los Huesos (SH) in the Sierra de Atapuerca (Burgos, Spain) have allowed us to reconstruct 27 complete long bones of the human species Homo heidelbergensis. The SH sample is used here, together with a sample of 39 complete Homo neanderthalensis long bones and 17 complete early Homo sapiens (Skhul/Qafzeh) long bones, to compare the stature of these three different human species. Stature is estimated for each bone using race- and sex-independent regression formulae, yielding an average stature for each bone within each taxon. The mean length of each long bone from SH is significantly greater (p < 0.05) than the corresponding mean values in the Neandertal sample. The stature has been calculated for male and female specimens separately, averaging both means to calculate a general mean. This general mean stature for the entire sample of long bones is 163.6 cm for the SH hominins, 160.6 cm for Neandertals and 177.4 cm for early modern humans. Despite some overlap in the ranges of variation, all mean values in the SH sample (whether considering isolated bones, the upper or lower limb, males or females or more complete individuals) are larger than those of Neandertals. Given the strong relationship between long bone length and stature, we conclude that SH hominins represent a slightly taller population or species than the Neandertals. However, compared with living European Mediterranean populations, neither the Sima de los Huesos hominins nor the Neandertals should be considered ‘short’ people. In fact, the average stature within the genus Homo seems to have changed little over the course of the last two million years, since the appearance of Homo ergaster in East Africa. It is only with the emergence of H. sapiens, whose earliest representatives were ‘very tall’, that a significant increase in stature can be documented.     

Intrapopulational body size variation and cranial capacity variation in middle pleistocene humans: The Sima de los Huesos sample (Sierra de Atapuerca,Spain)

A sexual dimorphism more marked than in living humans has been claimed for European Middle Pleistocene humans, Neandertals and prehistoric modern humans. In this paper, body size and cranial capacity variation are studied in the Sima de los Huesos Middle Pleistocene sample. This is the largest sample of non-modern humans found to date from one single site, and with all skeletal elements represented. Since the techniques available to estimate the degree of sexual dimorphism in small palaeontological samples are all unsatisfactory, we have used the bootstraping method to asses the magnitude of the variation in the Sima de los Huesos sample compared to modern human intrapopulational variation. We analyze size variation without attempting to sex the specimens a priori. Anatomical regions investigated are scapular glenoid fossa; acetabulum; humeral proximal and distal epiphyses; ulnar proximal epiphysis; radial neck; proximal femur; humeral, femoral, ulnar and tibial shaft; lumbosacral joint; patella; calcaneum; and talar trochlea. In the Sima de los Huesos sample only the humeral midshaft perimeter shows an unusual high variation (only when it is expressed by the maximum ratio, not by the coefficient of variation). In spite of that the cranial capacity range at Sima de los Huesos almost spans the rest of the European and African Middle Pleistocene range. The maximum ratio is in the central part of the distribution of modern human samples. Thus, the hypothesis of a greater sexual dimorphism in Middle Pleistocene populations than in modern populations is not supported by either cranial or postcranial evidence from Sima de los Huesos. Am J Phys Anthropol 106:19–33, 1998. © 1998 Wiley-Liss, Inc.     

Endocranial traits of the Sima de los Huesos (Atapuerca,Spain) and Petralona (Chalkidiki,Greece) Middle Pleistocene ursids. Phylogenetic and biochronological implications

A complete cranium of Ursus deningeri from Petralona (Chalkidiki, Greece) covered by a thick carbonate crust has been virtually liberated through CT scan and 3D image reconstruction, and compared with a specimen from the Sima de los Huesos, Sierra de Atapuerca (Spain) Middle Pleistocene site. X-ray computed tomography allowed for the identification of previously unrecognized and phylogenetically relevant traits. Analysis of these traits and an additional series of classically defined traits demonstrate the near identity of these specimens, thereby, confirming an early stage of the speloid “(cave bear)” condition. The replicate luminescence ages obtained for the SH deposit provide a combined minimum age estimate of 427 ± 12 ka for the underlying fossils. Based on a series of primitive and derived morphological features of these two crania, a similar age is here proposed for the Petralona and SH U. deningeri.     

Early Pleistocene human mandible from Sima del Elefante (TE) cave site in Sierra de Atapuerca (Spain): a comparative morphological study

We present a detailed morphological comparative study of the hominin mandible ATE9-1 recovered in 2007 from the Sima del Elefante cave site in Sierra de Atapuerca, Burgos, northern Spain. Paleomagnetic analyses, biostratigraphical studies, and quantitative data obtained through nuclide cosmogenic methods, place this specimen in the Early Pleistocene (1.2-1.3 Ma). This finding, together with archaeological evidence from different European sites, suggests that Western Europe was colonised shortly after the first hominin expansion out of Africa around the Olduvai subchron. Our analysis of the ATE9-1 mandible includes a geometric morphometric analysis of the lower second premolar (LP₄), a combined and detailed external and internal assessment of ATE9-1 roots through CT and microCT techniques, as well as a comparative study of mandibular and other dental features. This analysis reveals some primitive Homo traits on the external aspect of the symphysis and the dentition shared with early African Homo and the Dmanisi hominins. In contrast, other mandibular traits on the internal aspect of the symphysis are derived with regard to African early Homo, indicating unexpectedly large departures from patterns observed in Africa. Reaching the most occidental part of the Eurasian continent implies that the first African emigrants had to cross narrow corridors and to overcome geographic barriers favouring genetic drift, long isolation periods, and adaptation to new climatic and seasonal conditions. Given these conditions and that we are dealing with a long time period, it is possible that one or more speciation events could have occurred in this extreme part of Eurasia during the Early Pleistocene, originating in the lineages represented by the Sima del Elefante-TE9 hominins and possibly by the Gran Dolina-TD6 hominins. In the absence of any additional evidence, we prefer not include the specimen ATE9-1 in any named taxon and refer to it as Homo sp.     

Early Pleistocene human mandible from Sima del Elefante (TE) cave site in Sierra de Atapuerca (Spain): a palaeopathological study

Here we present a detailed palaeopathological study of the hominin mandible ATE9-1 found at the Sima del Elefante site (TE), Sierra de Atapuerca, Spain. This fossil represents the earliest hominin remains from Western Europe with an age of ca. 1.3 Ma. The specimen displays several dento-gnathic lesions; the antiquity and geographic location of this fossil justifies a detailed palaeopathological study to determine if the pathologies have significantly altered taxonomically relevant features. Our study reveals severe dental attrition combined with generalized hypercementosis, alveolar root exposure, mild periodontal disease, tooth dislocation, and an anomalous occlusal plane. We have also observed calculus deposits, two cystic lesions and an anomalous wear facet compatible with tooth picking. The majority of these pathological signs can be explained by compensatory eruption. We propose that these lesions are associated as causes, consequences, and amplifiers of one another within the framework of heavy and even traumatic occlusion, masticatory habits, or both traumatic occlusion and masticatory habits. Despite the severity of these lesions, occlusion was at least partially functional so it was unlikely to influence the survival of this individual. In addition, the lesions do not prohibit the taxonomic assessment of the mandible.     

Description d’un bassin fragmentaire de Paranthropus robustus du site Plio-Pléistocène de Drimolen (Afrique du Sud)

The Plio-Pleistocene site of Drimolen (Gauteng Province, South Africa) has yielded a fragmentary adult pelvis, DNH 43, composed of a robust, right innominate bone (DNH 43B) associated with the sacrum and the posterior arch of the last lumbar vertebra (DNH 43 A). Comparisons with other Plio-Pleistocene hominids (AL 288.1, Sts 14, Sts 65, Stw 431, TM 1605, SK 50, SK 3155b) pelves have been made which indicate that this specimen belongs to Paranthropus robustus. The ilium of the Drimolen hominid is narrowed just above the acetabulum. The small auricular surface is set far away from the acetabulum. The sacrum is curved, the upper lateral angles are clearly expressed. Some anatomical features reveal a lumbar lordosis in DNH 43. This lumbar lordosis is specific of australopithecines because different from extant human.     

L’approvisionnement en matières premières lithiques au Pléistocène inférieur et moyen dans la Sierra de Atapuerca, Burgos (Espagne)

This paper summarizes the latest studies on lithic raw material raising that are currently undertaken within the Sierra de Atapuerca research project. During the past two years, several works have provided new petrographical and technological data, contributing to the knowledge of the kinds of materials exploited by the Atapuerca hominids, as well as the areas where those materials were raised. The sites yielding this information are Gran Dolina (Lower and Middle Pleistocene) and Galeria (Middle Pleistocene), both located in the Trinchera del Ferrocarril archeopaleontological complex.