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Liang Bua 1 (LB1) exhibits marked craniofacial and postcranial asymmetries and other indicators of abnormal growth and development. Anomalies aside, 140 cranial features place LB1 within modern human ranges of variation, resembling Australomelanesian populations. Mandibular and dental features of LB1 and LB6/1 either show no substantial deviation from modern Homo sapiens or share features (receding chins and rotated premolars) with Rampasasa pygmies now living near Liang Bua Cave. We propose that LB1 is drawn from an earlier pygmy H. sapiens population but individually shows signs of a developmental abnormality, including microcephaly. Additional mandibular and postcranial remains from the site share small body size but not microcephaly. Indonesia | microcephaly | skeletal pathology | asymmetry | dentition

A new method for quantifying cranial and cerebral shape and asymmetry fits symmetric superquadric geometric models to three-dimensional coordinate measurements. Asymmetry is quantified as radial residuals of the surface data points from their best-fit superquadric models. Twenty human crania, 10 magnetic resonance imaging (MRI) exocranial surfaces, and 10 corresponding MRI cerebral surfaces as well as two infant head casts were digitized and modeled using superquadrics. Superquadric parameters have simple geometric interpretation, are very reproducible, and demonstrated statistically significant differences between crania of Amerindian ancestry and MRI exocranial surfaces of European ancestry used in this study. Superquadric models demonstrated strong congruence between MRI exocranial and cerebral surfaces. Typical asymmetry was 1-5 mm. Lastly, polar contour plots of radial residuals for head casts before and after orthotic cranioplasty demonstrated the efficacy of using superquadrics to quantify positional plagiocephaly and synostosis of infant crania. KEY WORDS geometric model; calvaria; squareness; taper; plagiocephaly

Late Miocene fossils from the Lukeino Formation in Kenya's Tugen Hills are assigned to Orrorin tugenensis. Of 20 fossils recovered there to date, 3 are proximal femurs. One of these, BAR 1002'00, preserves an intact head connected to the proximal shaft by an elongated neck. Although this fossil is comparable In size to Pan troglodytes, computerized tomography scans of the neck-shaft junction of BAR 1002'00 reveal that the cortex is markedly thinner superiorly than inferior[y, differing from the approximately equal cortical thicknesses observed in extant African apes, approaching the condition in later hominids, and indicating that O. tugenensis was bipedal., Orrorin tugenensis is thought to represent some of the earliest known hominids, securely dated biostratigraphically, geologically, and radiontetrically, as well as by paleomagnetism, to the Late Miocene, approximately 6 million [...]

During the century following publication of Darwin's Origin of Species, 10 or more taxa of fossil hominids commonly were recognized, with the numbers of genera and species ranging to as high as about 14. Surprisingly, given the great advances made over the last several decades in numbers of known fossil hominid specimens, abundance of comparative morphological data available on extant nonhuman primates, and extensive analyses of genetic variation, the present situation accepted by some paleoanthropologists appears to be one of conceptual stasis. The last fifteen years have encompassed a systematic program of genetic distance studies among numerous groups of large mammals, with much of the work having been carried out by Stephen O'Brien and his colleagues. These data provide a context for testing hypotheses about the numbers of hominid taxa that might have existed over the past several million years. A baseline is established by the genetic distance between extant humans and common chimpanzees (D = 0.244). If this distance is apportioned among 14 hypothetical hominid taxa, the average estimated distance among hominid groups would be less than the distance between Bornean and Sumatran orangutans (D -- 0.025), which interbreed freely. Even if the distance between extant humans and common chimpanzees is subdivided among only 5 taxa, a number of species commonly postulated to be on a direct line from the common ancestor of hominids and chimpanzees to extant humans, the estimated distance among hypothetical hominid taxa is less than half the genetic distance between lions and tigers (D = 0.121), which also are interfertile. If other mammalian groups provide a valid general standard, then the large numbers of hypothetical hominid taxa recognized on morphological grounds cannot have differed from each other very much in genetic terms, raising questions about the nature of relationships among hominid populations. Conceptually, a shift away from formal taxonomy would coincide with the increasing recognition that several important attributes of species (such as morphological distinctiveness and genetic isolation) very commonly do not coincide.