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Objectives: The elbow of Nacholapithecus has been extensively described qualitatively, however its ulnar morphology has never been the focus of an in‐depth quantitative analysis before. Hence, our main aim is quantifying the proximal ulnar morphology in Nacholapithecus and exploring whether it is similar to those of Equatorius and Griphopithecus as previously reported. Materials and Methods: We compared Nacholapithecus proximal ulnar morphology with a sample of extant and extinct anthropoids through principal component analysis and agglomerative hierarchical cluster analysis. Moreover, we calculated the Cophenetic Correlation Coefficient and checked for taxonomical group mean differences through MANOVA and pairwise post‐hoc comparisons, as well as the phylogenetic signal in the variables used. Results: The Nacholapithecus ulna displays a moderately long and relatively narrow olecranon, a relatively wide trochlear surface‐radial notch width, and a relatively thin sigmoid notch depth. These features resemble those of large papionins and chimpanzees, and some extinct taxa, mainly Equatorius. Discussion: Results presented here reinforce previous inferences on the functional morphology of the Nacholapithecus elbow, showing adaptations for general quadrupedal behaviors. However, other derived features (e.g., a relatively wide trochlear surface) might be associated with the ape‐like traits described for its distal humerus (e.g., wide trochlear groove), thus displaying a combination of primitive and derived features in the proximal ulna. Finally, affinities with large papionins could suggest the presence of some terrestrial habits in Nacholapithecus. However, the lack of evidence in the rest of the skeleton prevents us from suggesting terrestrial affinities in this taxon in a conclusive manner. [ABSTRACT FROM AUTHOR]

Objectives: Metatarsal bones constitute a key functional unit of the foot in primates. While the form‐function relationships of metatarsals have been extensively studied, particularly in relation to the loss of the grasping ability of the foot in humans in contrast to apes, the effect of phyletic history on the metatarsal morphology and its variability remains largely unknown. Materials and Methods: Here, we evaluate how the strength of the phylogenetic signal varies from the first to the fifth metatarsal in humans, chimpanzees, gorillas, orangutans, gibbons, and Japanese macaques. We use computed tomography imaging and morphometric mapping to quantify the second moment of area around and along the metatarsal shaft and evaluate the strength of the phylogenetic signal with multivariate K‐statistics. Results: The shaft structure of the first metatarsal, but not the others, correlates well with the phylogeny of apes and humans. Discussion: Given the importance of the first metatarsal for grasping and bipedal/quadrupedal locomotion, the strong phylogenetic but weak functional signal in its structure is unexpected. These findings suggest that the evolutionary diversification of hominoid locomotor behaviors, including human bipedality, is only partly reflected in form‐function relationships of key skeletal elements, and that phylogenetic history acted as a major evolutionary constraint. [ABSTRACT FROM AUTHOR]

The liquefaction-induced river levee failures observed at micro-scale landforms of an old river course during the 2011 Tohoku earthquake were investigated by means of weight sounding and soil sampling. An empirical procedure to evaluate the liquefaction resistance of soils using weight sounding and soil sampling is proposed, which explicitly incorporates the effect of the fines content of soils. Case studies were carried out at three locations along Kokaigawa River. The use of weight sounding and soil sampling proves effective in discerning the geotechnical reasons behind the occurrence of the river levee failures observed at the old river course. [ABSTRACT FROM AUTHOR]

Old World monkeys represent one of the most successful adaptive radiations of modern primates, but asparse fossil record has limited our knowledge about the early evolution of this clade. We report the discovery of two partial skeletons of an early colobine monkey (Microcolobus) from the Nakali Formation (9.8-9.9 Ma) in Kenya that share postcranial synapomorphies with extant colobines in relation to arboreality such as mediolaterally wide distal humeral joint, globular humeral capitulum, distinctly angled zona conoidea, reduced medial trochlear keel, long medial epicondyle with weak retroflexion, narrow and tall olecranon, posteriorly dislocated fovea on the radial head, low projection of the femoral greater trochanter, wide talar head with a greater rotation, and proximodistally short cuboid and ectocuneiform. Microcolobus in Nakali clearly differs from the stem cercopithecoid Victoriapithecus regarding these features, as Victoriapithecus is postcranially similar to extant small-sized terrestrial cercopithecines. However, degeneration of the thumb, a hallmark of modern colobines, is not observed, suggesting that this was a late event in colobine evolution. This discovery contradicts the prevailing hypothesis that the forest invasion by cercopithecids first occurred in the Plio-Pleistocene, and shows that this event occurred by the late Miocene at a time when ape diversity declined. Am J Phys Anthropol 143:365-382, 2010. [c] 2010W iley-Liss, Inc. KEY WORDS Old World monkeys; fossils; Colobinae; Cercopithecinae; locomotion DOI 10.1002/ajpa.21327

We constructed a three-dimensional whole-body musculoskeletal model of the Japanese macaque (Macaca fuscata) based on computed tomography and dissection of a cadaver. The skeleton was modeled as a chain of 20 bone segments connected by joints. Joint centers and rotational axes were estimated by joint morphology based on joint surface approximation using a quadric function. The path of each muscle was defined by a line segment connecting origin to insertion through an intermediary point if necessary. Mass and fascicle length of each were systematically recorded to calculate physiological cross-sectional area to estimate the capacity of each muscle to generate force. Using this anatomically accurate model, muscle moment arms and force vectors generated by individual limb muscles at the foot and hand were calculated to computationally predict muscle functions. Furthermore, three-dimensional whole-body musculoskeletal kinematics of the Japanese macaque was reconstructed from ordinary video sequences based on this model and a model-based matching technique. The results showed that the proposed model can successfully reconstruct and visualize anatomically reasonable, natural musculoskeletal motion of the Japanese macaque during quadrupedal/bipedal locomotion, demonstrating the validity and efficacy of the constructed musculoskeletal model. The present biologically relevant model may serve as a useful tool for comprehensive understanding of the design principles of the musculoskeletal system and the control mechanisms for locomotion in the Japanese macaque and other primates.