Neanderthal child's maxilla from Baume Moula-Guercy (Soyons, Ardèche, France).

This article provides an ontogenetically-based comparative description of the Guercy 3 partial child's maxilla with Rdm2 -RM1 and unerupted RI2 -RP4 from Baume Moula-Guercy (MIS 5e) and examines its affinities to European and Middle Eastern Middle-to-Late Pleistocene (≈MIS 14-MIS 1) Homo. Description of the Guercy 3 maxilla and dentition (7.0 year ± 0.9 month) is based on observations of original fossils, casts, CT scans, literature descriptions, and virtual reconstructions. Our ontogenetic sample comprises a Preneanderthal-Neanderthal group and a Homo sapiens group. These groups are subdivided into (1) Preneanderthals (≈MIS 14-9), Early Neanderthals (MIS 7-5e), and Late Neanderthals (MIS 5d-3), and (2) Middle (MIS 5), Upper (MIS 3-2), and Late Upper Paleolithic (≈MIS 1), and recent H. sapiens. Standard techniques were employed for measurements and developmental age determinations.The Guercy 3 maxilla lacks changes found in Late Neanderthals, including the positioning of the root of the zygomatic process, infraorbital and nasal plates, premaxilla, buccal and labial alveolus, maxillary sinus, nasal cavity, and verticality of anterior tooth implantation. The morphology of the Guercy 3 maxilla more closely approximates that of Sima de los Huesos Preneanderthals, while the dentition more closely approximates the Early-Late Neanderthal condition. Maxillary remains of children and juveniles between MIS 14-MIS 5e are rare, and the available sample is fragmentary and distorted. Although fragmentary, the Guercy 3 maxilla is undistorted and provides new insights into the evolution of the midface in Neanderthals.

Endocranial anatomy of the Guercy 1 early Neanderthal from Baume Moula-Guercy (Soyons, Ardèche, France).

We provide the first comparative description of the endocranium of the Guercy 1 Early Neanderthal and examine its affinities to Preneanderthals, Neanderthals, and Homo sapiens. The Guercy 1 cranium derives from deposits chronostratigraphically and biostratigraphically dated to the Eemian Interglacial (MIS 5e). For comparative purposes, we compiled a sample of European and Southwest Asian subadult and adult Middle-to-Late Pleistocene hominins (≈MIS 12-MIS 1; N = 65). We sampled both a Preneanderthal-Neanderthal group and a Homo sapiens group. The Preneanderthal-Neanderthal group was further divided into three time-successive subgroups defined by associated MIS stages. Metric and morphological observations were made on original fossils and physical and virtual endocranial reconstructions. Guercy 1 and other Early Neanderthals, differ from Preneanderthals by increased development of the prefrontal cortex, precentral and postcentral gyri, inferior parietal lobule, and frontoparietal operculum. Early Neanderthal differ, in general, from Late Neanderthals by exhibiting less development in most of the latter brain structures. The late group additionally differentiates itself from the early group by a greater development of the rostral superior parietal lobule, angular gyrus, superior and middle temporal gyri, and caudal branches of the superior temporal gyrus. Endocranial morphology assessed along the Preneanderthal-Neanderthal sequence show that brain structures prominent in Preneanderthals are accentuated in Early-to-Late Neanderthals. However, both the Early and Late groups differentiate themselves by also showing regionally specific changes in brain development. This pattern of morphological change is consistent with a mosaic pattern of neural evolution in these Middle-to-Late Pleistocene hominins.

Neanderthal cranial remains from Baume Moula-Guercy (Soyons, Ardèche, France).

OBJECTIVES: We provide the first comparative description of the Guercy 1 cranium and isolated cranial fragments from Baume Moula-Guercy and examine their affinities to European Preneanderthals, Neanderthals, and Homo sapiens. MATERIALS AND METHODS: The Moula-Guercy hominins derive from deposits chronostratigraphically and biostratigraphically dated to the Eemian Interglacial (MIS 5e). For comparisons we compiled a sample of European and Southwest Asian subadult-adult Middle-to-Late Pleistocene hominins (≈MIS 14-MIS 2; N = 184). This sample represents a Preneanderthal-Neanderthal group and a H. sapiens group, both of which were further divided into three time-successive subgroups defined by associated marine isotope stages (MIS). Metric and morphological observations were made on the original fossils and a virtual reconstruction of Guercy 1. Developmental age and sex and the minimum-maximum number of individuals were assessed. RESULTS: Guercy 1 represents the remains of a late stage adolescent (≈15-16.0 years) female. Morphological and metric data combine to associate the total morphological pattern expressed in Guercy 1 with our MIS 7-MIS 5e ("Early Neanderthal") subgroup. Some features, especially those related to the frontal, suggest linkage to a paleodeme comprising the Moula-Guercy, Artenac, La Chaise Abri Suard and, possibly, the Biache-Saint-Vaast samples. DISCUSSION: Remains of MIS 7-MIS 5e Neanderthals are rare and fragmentary, especially those dated to the Last Interglacial. The Baume Moula-Guercy sample provides new insights into the total morphological pattern expressed in MIS 5e Neanderthals. Further, our results support earlier suggestions that MIS 7-MIS 5e European hominins represent a morphotype that is distinct from both earlier and later members of the Preneanderthal-Neanderthal group.

Bear phalanx traumatically introduced into a living human: Prehistoric evidence.

Traumatically induced skeletal injuries are common and can be ascribed to a normal range of events occurring in an individual's lifetime. A subset of these trauma-induced injuries provides enhanced insight into cultural history. Such cases might include those referable to medico-surgical and religious/ritualistic practices. We describe prehistoric evidence and cultural implications of the traumatic insertion of an Ursus manual phalanx into the elbow of a living human. The injury healed and the phalanx remained in situ until death. The individual derives from the Ellis Landing shellmound and dates to a subphase of the Middle Period (≈500BC-300AD) in the California cultural sequence. The remains are of a 30-40 year-old female. Comparative data on arm morphology and pathological conditions present were collected (n=159). Three Ursus subspecies (n=15) were examined to identify the taxon represented by the phalanx. The described individual was probably wearing bear paw ornaments at the time she was crushed by a heavy object. During this event, a bear claw was driven into her cubital fossa, the basal phalangeal tubercle being impressed into the humerus. The wound healed completely. The presence of Ursus body parts indicates an elevated societal role for this female; most likely she was a shaman or healer.

Color changes in modern and fossil teeth induced by synchrotron microtomography.

Studies using synchrotron microtomography have shown that this radiographic imaging technique provides highly informative microanatomical data from modern and fossil bones and teeth without the need for physical sectioning. The method is considered to be nondestructive; however, researchers using the European Synchrotron Radiation Facility have reported that color changes sometimes occur in teeth during submicron scanning. Using the Advanced Light Source, we tested for color changes during micron-level scanning and for postexposure effects of ultraviolet light. We exposed a 2.0-mm wide strip (band) to synchrotron light in 32 specimens, using multiple energy levels and scan durations. The sample included modern and fossilized teeth and bone. After scanning, the specimens were exposed to fluorescent and direct ultraviolet light. All teeth showed color changes caused by exposure to synchrotron radiation. The resulting color bands varied in intensity but were present even at the lowest energy and shortest duration of exposure. Color bands faded during subsequent exposure to fluorescent and ultraviolet light, but even after extensive ultraviolet exposure, 67% (8/12) of UV-exposed teeth retained some degree of induced color. We found that the hydroxyapatite crystals, rather than the organic component, are the targets of change, and that diagenesis appears to impact color retention. Color changes have significance beyond aesthetics. They are visible indicators of ionization (chemical change) and, therefore, of potential physical damage. It is important for researchers to recognize that synchrotron microtomography may damage specimens, but adopting suitable safeguards and procedures may moderate or eliminate this damage.

Foramen magnum ontogeny in Homo sapiens: a functional matrix perspective.

Historically, the foramen magnum (FM) has been an integral component of studies on skull ontogeny and evolutionary transformations of cranial form. Although this foramen has been considered a single entity, we hypothesize that it comprises two functional matrices, a ventral matrix and a dorsal matrix. In general, the ventral matrix is related to locomotor functions, whereas the dorsal matrix is related to neurological functions and fluid flow dynamics. To test our hypothesis, we used a large ontogenetic sample of modern human crania (seventh fetal month to adult) to (1) delineate bony size and shape ontogeny for both the foramen and its dorsal and ventral units; (2) delineate the role of synchondroses in the observed growth patterns and rates; and (3) explore the relationship between FM and cranial size, shape, and growth. Detailed growth patterns and rates are established for the bony FM and its ventral and dorsal skeletal units. These data are supplemented by literature and observational data on embryonic and fetal FM ontogeny, soft tissue relationships, anomalous/pathological extremes of size, and craniocervical anatomy and locomotor functions. The hypothesis that the FM is composed of a ventral and a dorsal functional matrix is supported by observed ontogenetic differences between ventral and dorsal skeletal units, as well as by the soft tissue anatomy of these matrices. Further documentation of these matrices has the potential to significantly enhance our understanding of the ontogenetic and evolutionary transformations of skull base morphology.

Genetic, physiologic and ecogeographic factors contributing to variation in Homo sapiens: Homo floresiensis reconsidered.

A new species, Homo floresiensis, was recently named for Pleistocene hominid remains on Flores, Indonesia. Significant controversy has arisen regarding this species. To address controversial issues and refocus investigations, I examine the affinities of these remains with Homo sapiens. Clarification of problematic issues is sought through an integration of genetic and physiological data on brain ontogeny and evolution. Clarification of the taxonomic value of various 'primitive' traits is possible given these data. Based on this evidence and using a H. sapiens morphological template, models are developed to account for the combination of features displayed in the Flores fossils. Given this overview, I find substantial support for the hypothesis that the remains represent a variant of H. sapiens possessing a combined growth hormone-insulin-like growth factor I axis modification and mutation of the MCPH gene family. Further work will be required to determine the extent to which this variant characterized the population.

Pleistocene Homo sapiens from Middle Awash, Ethiopia.

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.

Mandibular condyle traits in Neanderthals and other Homo: a comparative, correlative, and ontogenetic study.

The relationship between the mandibular condyle and the crest of the mandibular notch (CMN) has historically entered into discussions of Neanderthal characteristics and was recently suggested to be autapomorphic in Neanderthals. The Neanderthal CMN has been described as intersecting the condyle in the middle, while the modern human CMN runs to the condyle's lateral end. A large lateral condylar tubercle (LCT) has also been observed in Neanderthals and thought to be related to medial (or less lateral) CMN position. In addition, the presence of a less lateral CMN early in ontogeny, as seen in the Amud 7 infant, has been argued to demonstrate great evolutionary divergence in Neanderthals. Using a scoring system for each trait, this study first examines the expression of CMN position and LCT size in 102 adult modern humans and in samples of Neanderthals and other fossil Homo. Then, CMN position is scored in 208 subadult modern humans to elucidate the ontogeny of this trait. Results show that CMN position is not autapomorphic in Neanderthals, but Neanderthals have significantly more CMNs in the least-lateral score category than does the modern human sample. Large LCTs are found to be strongly predictive of less lateral CMN position, although less lateral CMN position may exist in the absence of a large LCT. The complex ontogenetic pattern of CMN expression observed indicates that features of subadult and adult condylar morphology cannot be constructively compared without first considering subadult morphology on its own functional and developmental terms.

Missing Omo L338y-6 occipital-marginal sinus drainage pattern: ground sectioning, computer tomography scanning, and the original fossil fail to show it.

The Omo L338y-6 occipital region has been recently studied by White and Falk (1999), who claim that it shows a readily identifiable enlarged left occipital-marginal sinus (O/M). These observations are contrary to the direct observations of previous investigators (Rak and Howell, 1978; Kimbel, 1984; Holloway, 1981; Holloway, 1988). White and Falk (1999) further argue that the presence of this enlarged O/M strongly suggests that the Omo L338y-6 hominid was indeed a "robust" Australopithecus. We used direct sectioning and CT scanning to analyze magnified sections of a high-quality first-generation cast of the newly cleaned original fossil. These methods fail to show any evidence of a morphological landmark that can be interpreted as an enlarged O/M, either as an eminence or a sulcus. In contrast, the same techniques used with both SK 1585 and OH5 ("robust" Australopithecus with an enlarged O/M) show extremely visible and palpable enlarged O/M's. Examination of the original Omo fossil confirms that it lacks an O/M. This evidence clearly shows that an enlarged O/M cannot be identified on either the original fossil or a first-generation cast, although this does not rule out the possibility that the Omo L338y-6 hominid was a "robust" Australopithecus. We believe that the differences between observers regarding this feature are most probably due to displacement caused by a crack and the different source materials employed, i.e., the difference between a first-generation cast of the original fossil and a third- or fourth-generation cast of the endocast made two decades ago.