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

A 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.

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. Anat Rec, 294:199-216, 2011. V V C 2010 Wiley-Liss, Inc.Key words: foramen magnum; ontogeny; human variation; functional matricesThe basicranium forms in a zone of interaction between structures with neural, skeletomotor, respiratory, auditory, masticatory, digestive, and visual functions. Because of the complex structural-functional relationships, the morphology of the basicranium reflects compromises resulting from the competing demands of multiple soft tissue units that are responding to essential functions.During basicranial development, the structures traversing the endocranial-ectocranial boundary become encircled by cartilage and, eventually, by bone. The resulting bony foramina of the basicranium respond in Additional Supporting Information may be found in the online version of this article.

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.

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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.

Microcephaly is a severe developmental abnormality which is induced either genetically or environmentally. The archaeological evidence for the occurrence of this abnormality is minimal. Out of six possible cases, only three have been published; all are adult and represented solely by cranial remains. The focus of the current study is the nearly complete skeleton of a 3-year-old child recovered during archaeological excavations in San Jose, California. The individual is compared to a sample of 184 California Indians, ranging from 0.5 to 5 years, which were also recovered from archaeological excavations. In order to determine if microcephaly was the only disorder represented, metrical comparisons of the skull and postcrania and gross morphological comparisons of endocranial casts were made. Based on these comparisons the individual was determined to have a cranial vault size comparable to 6-month-old infants (630 cc), a facial skeleton equivalent to the 9-month-old to 2-year-old age groups, and a reduced stature. Due to the mosaic nature of the skull, the observed morphology was interpreted in terms of functional cranial components. Severe malformation of the orbital aspect of the frontal lobes was found in conjunction with a significant reduction in size of the cerebral cortex and left temporal lobe. On the basis of this analysis, the individual was found to exhibit the total morphological pattern associated with microcephaly. A differential diagnosis of other possible genetic disorders is also presented.

Hydrocephalus is a severe disorder of the central nervous system characterized by absorption blockage of the cerebral spinal fluid (CSF). The archaeological record of the condition ranges in time from 10,000 B.C. to 1670 A.D. and consists of 30 possible cases worldwide. A review of this material reveals that diagnostic criteria which fully delineate the condition have not been established. Previously, no attempt has been made to differentiate the two major categories of hydrocephalus and their subgroupings, or to identify other conditions which might result in similar morphologies. A partial child's skeleton from the Middle Period (ca. 2500 B.C. to 500 A.D.) of Central California Prehistory is described in light of an extensive clinical literature. Examination of this individual reveals a unique craniofacial configuration and malformed postcrania. Bony criteria for a differential diagnosis of hydrocephalus are established and applied to this individual. Based on these criteria, the individual is diagnosed as having a chronic form of noncommunicating hydrocephalus. Blockage of the CSF pathway most likely occurred in the aqueduct of Sylvius with a partial occlusion of the foramen of Monro or a frontal cyst. In addition, femoral development is suggestive of partial paralysis.