We investigated mechanical dietary properties of sympatric bamboo lemurs, Hapalemur g. griseus, H. aureus, and H. (Prolemur) simus, in Ranomafana National Park, Madagascar. Each lemur species relies on bamboo, though previous behavioral observations…
It was proposed that the power stroke in primates has two distinct periods of occlusal contact, each with a characteristic motion of the mandibular molars relative to the maxillary molars. The two movements are called phase I and phase IT, and they…
Even though in vivo studies of mastication in living primates are often used to test functional and adaptive hypotheses explaining primate masticatory behavior, we currently have little data addressing how experimental procedures performed in the…
Free-ranging primates are confronted with the challenge of maintaining an optimal range of body temperatures within a thermally dynamic environment that changes daily, seasonally, and annually. While many laboratory studies have been conducted on…
The jaw-closing muscles are responsible for generating many of the forces and movements associated with feeding. Muscle physiologic cross-sectional area (PCSA) and fiber length are two architectural parameters that heavily influence muscle function.…
Common (Callithrix jacchus) and pygmy (Cebuella pygmaea) marmosets and cotton-top tamarins (Saguinus oedipus) share broadly similar diets of fruits, insects, and tree exudates. Marmosets, however, differ from tamarins in actively gouging trees with…
The relationship between mandibular form and biomechanical function is a topic of significant interest to morphologists and paleontologists alike. Several previous studies have examined the morphology of the mandible in gouging and nongouging…
Physical anthropologists have devoted considerable attention to the structure and function of the primate prehensile tail. Nevertheless, previous morphological studies have concentrated solely on adults, despite behavioral evidence that among many…
Uncertainties as to the nature and implications of osteoarthritis and calcium pyrophosphate deposition disease (CPPD) in primates were subject to critical review through examination of 153 prosimians and 1,250 Old World non-prosimian primates.…
The opportunity to examine the defleshed skeleton of an individual diagnosed in life (Hamann-Todd collection, individual 2036) afforded a unique opportunity to demonstrate the bone damage characteristic of at least one form of juvenile rheumatoid…
Presence of spine and sacroiliac involvement and the nature and distribution of the erosive lesions allow definitive diagnosis of spondyloarthropathy. Thus, spondyloarthropathy was identified in Theropithecus, Papio, Cercopithecus, Macaca, Colobus,…
The reliability of visual examination of defleshed bones was assessed for detection of postcranial metastatic disease in individuals known to have had cancer. This was compared with standard clinical radiologic techniques. The skeletons of 128…
Characterization of the nature and skeletal distribution of gout was accomplished in a Chamoru (Chamorros) population with predilection to the disease. Uniform excavation by the gouty diathesis produces a punched-out appearance to these predominantly…
OBJECTIVES: Laboratory studies have yielded important insights into primate locomotor mechanics. Nevertheless, laboratory studies fail to capture the range of ecological and structural variation encountered by free-ranging primates. We present…
The importance of locomotion to evolutionary fitness has led to extensive study of primate locomotor behavior, morphology and ecology. Most previous research has focused on adult primates, but in the last few decades, increased attention to locomotor…
OBJECTIVES: Relatively long digits are considered to enhance grasping performance in primates. We tested whether growth-related changes in intrinsic hand and foot proportions may have behavioral implications for growing animals, by examining whether…
OBJECTIVES: Dental eruption schedules have been closely linked to life history variables. Here we examine a sample of 50 perinatal primates (28 species) to determine whether life history traits correlate with relative tooth size at birth. MATERIALS…
Young primates have relatively large hands and feet for their body size, perhaps enhancing grasping ability. We test the hypothesis that selection for improved grasping ability is responsible for these scaling trends by examining the ontogeny of…
OBJECTIVES: Platyrrhines span two orders of magnitude in body size and are characterized by diverse feeding behaviors and diets. While size plays an important role in primate feeding behavior and masticatory apparatus morphology, we know little about…
Despite the importance that concepts of arboreal stability have in theories of primate locomotor evolution, we currently lack measures of balance performance during primate locomotion. We provide the first quantitative data on locomotor stability in…
Locomotor researchers have long known that adult primates employ a unique footfall sequence during walking. Most mammals use lateral sequence (LS) gaits, in which hind foot touchdowns are followed by ipsilateral forefoot touchdowns. In contrast, most…
Jaw-joint height (JJH) above the occlusal plane is thought to be influenced by cranial base angle (CBA) and facial angulation during growth. To better understand how JJH relates to midline craniofacial form, we test the hypothesis that relative…
We examined masseter recruitment and firing patterns during chewing in four adult ring-tailed lemurs (Lemur catta), using electromyography (EMG). During chewing of tougher foods, the working-side superficial masseter tends to show, on average, 1.7…
We examined masseter and temporalis recruitment and firing patterns during chewing in five male Belanger's treeshrews (Tupaia belangeri), using electromyography (EMG). During chewing, the working-side masseters tend to show almost three times more…
