ISSN:0015-5713    

DOI:10.1159/000157271

出版商:S. Karger AG    

年代:1996

数据来源: Karger

ISSN:0015-5713    

DOI:10.1159/000157179

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Noncercopithecid Miocene catarrhines share numerous features of their postcranial skeleton with extant platyrrhines, particularly pitheciines, cebines, and atelines. For any given fossil taxon, these similarities do not extend throughout the skeleton. Also there may be similarities to more than one platyrrhine taxon, within different parts of the postcranium, or even within a single bone. These similarities are of two types. Features that are most likely to be retentions from the primitive anthropoid condition are present in many Miocene taxa. They are part of functional complexes associated with the performance of quadrupedal and possibly orthograde climbing activities. Other features, especially present in nonhominoid primitive catarrhines, are related to the performance of suspensory behaviors, and reflect a partial convergence on the suspensory ateline condition.

ISSN:0015-5713    

DOI:10.1159/000157180

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The postcranial morphology of the arboreal white-cheeked mangabey (Lophocebus albigena) differs from that of partly terrestrial Cercocebus mangabeys (C. torquatus, C. galeritus). Its humerus has a reduced greater tuberosity, weak muscular insertions on the humeral shaft, less salient trochlear keels, a thinner diaphysis and less retroflexed medial epicondyle. The femur of L. alhigena is characterized by a lowered greater trochanter, a thinner shaft, a flattened distal epiphysis and a wide and shallow patellar surface. The forelimb is short relative to other limb segments. L. alhigena has attained these skeletal features by deducting the ancestral terrestrial adaptations, such as skeletal robusticity and joint restriction. Influences of phylogenetic inertia on the development of skeletal morphology are discussed.

ISSN:0015-5713    

DOI:10.1159/000157181

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The erector spinae muscles of the patas monkey, hamadryas baboon, and spider monkey were dissected and the origins and insertions were described in detail. In the two terrestrial monkeys, a well-developed thoracolumbar segment of the muscle was observed. This trait seems to correlate to the sagittal movement of this region required in the pronograde quadrupedal locomotion. On the other hand, the erector spinae muscle of the spider monkey is quantitatively not so well developed and the arrangement of the muscle bundles was simpler than in the terrestrial monkeys. The arboreal habit of the spider monkey seems not to demand powerful extension in the thoracolumbar junction, and spinal rotation seems to be more important.

ISSN:0015-5713    

DOI:10.1159/000157182

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Histochemical properties are investigated in the thoracic and lumbar epaxial muscles of Japanese macaques, Macaca fuscata. Whole transverse sections of the muscles were removed at the different levels of the thoracic and lumbar vertebrae and muscle fibre types were classified into type I and type II fibres on the basis of their histochemical profiles. In the lumbar region the iliocostalis and longissimus muscles have many type II fibres. In the thoracic region the iliocostalis muscle has more type I fibres than the longissimus muscle. The intermammillares and mammilloaccessorii muscles which lie medially and deep to the longissimus muscle in the lumbar region have an extremely large number of type I fibres. These differences in the distribution of muscle fibre types among and within muscles suggest that functional differentiation exists among and within the muscles.

ISSN:0015-5713    

DOI:10.1159/000157183

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The morphological and functional characteristics of the extensor digitorum and hallucis brevis muscles, the sole intrinsic muscles of the dorsum of the foot in the macaque, were investigated through dissection, the examination of muscle fibre composition, and counts of axon numbers. The total number of muscle fibers contained within the extensor digitorum (EHB) and extensor hallucis brevis (EDB) was almost 21,100. The population ratios of the three muscle fibre types of white, intermediate and red were 39, 23 and 38%, respectively, for EDB and 40, 23 and 37%, respectively, for EHB. The mean cross-sectional area of each fibre type (white, intermediate, red) tended to be larger in the EHB (2,098, 1,480 and 911 μm2) than in the EDB (1,695, 1,310 and 822 μm2) and the value were significantly different for white fibres of males. The percentage area of the three muscle fibre types and the ratio of the white, intermediate and red areas, were similar between the EHB (55, 23 and 22%, respectively) and the EDB (52, 23 and 25%, respectively). The white area was dominant with the value showing a somewhat larger figure in the EHB compared to that of the EDB. The number of motor units was estimated to be 197–234 on average and the innervation ratio was calculated as between 91 and 109. These results suggest that the muscle fibre composition and innervation ratio of the EHB and EDB, especially the EHB, might relate to the arboreal locomotion of the crab-eating maca

ISSN:0015-5713    

DOI:10.1159/000157184

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Developmental changes of muscle fibre composition in the various heads of the elbow, knee, and ankle extensors have been studied in three genera of cercopithecid monkeys. In order to circumvent the technical hindrances of usual histoenzymological procedures (fresh muscles need to be frozen at once at -80 °C), immunofluorescence methods were used and technical adjustments were successfully carried out to make the study of formaldehyde-preserved muscles possible. Clear responses to antibodies against adult fast myosin in newborn macaques demonstrated that, at birth, adult myosins have already replaced the fetal isoforms, thus providing a reliable marker for the study of postnatal evolution of the muscle fibre composition. For each one of the three joints, from birth to adulthood, the percentage of slow, fatigue-resistant fibres increases only in that head of the extensor muscle groups which is specialized in maintaining posture by counteracting gravity (the ‘postural’ head). Hence, the question is raised of the relationships between such cytological evolution, developmental changes in postural behaviour, and body weight incr

ISSN:0015-5713    

DOI:10.1159/000157185

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Results of a study of the femoral bicondylar angle in adult and juvenile humans and great apes are presented. These results raise the question of whether or not the measurement reference of this angle is valid. This is because humans and great apes have a very different growth process of the distal epiphyseal suture of the femur during the period between birth and adulthood. The approximately 3 million years old juvenile femoral diaphyses attributed to Australopithecus afarensis (AL 333-110 and AL 333-111) were also studied. These specimens show an insertion of the diaphysis into the epiphysis of the simplified type typical of modern humans. This region is more convoluted in nonhuman anthropoids. Pelvifemoral interrelations are investigated through both longitudinal and cross-sectional radiographic studies of 23 human children. Growth changes in bicondylar and collo-diaphyseal angles, total femoral and femoral neck lengths, and interacetabular distance are correlated with age and to each other. These results are used to demonstrate the distinctive features of the Australopithecus afarensis fossil, AL 288–

ISSN:0015-5713    

DOI:10.1159/000157186

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The obliquity of the femoral diaphysis accounts for the valgus position of the human knee joint and reduces bending moments in the frontal plane. A high angle of obliquity is considered a hallmark of hominid bipedality, but its functional importance has rarely been identified correctly. A biostatic investigation of the knee joint in various realistic positions unveils resultant joint forces which do not deviate greatly from the long axis of the femoral shaft. This is due to the length of the femur and to the shortness of the human foot. The flat epiphyseal suture is more or less perpendicular to these joint forces, and the equal size of the femoral condyles reflects the even distribution of forces between them. In great apes the resultant forces acting in the knee joint vary considerably in dependence on the degree of flexion and rotation of the knee joint. The resultant joint force may be in line with the femur shaft or diverge. The epiphyseal surfaces offer facets to all joint forces found in the course of the study. Due to the pronounced varus position of the knee joint, the joint itself and the adjacent part of the femur are under medially concave bending moments, which lead to higher compressive forces at the medial than at the lateral condyle. The enlarged medial condyle allows the distribution of medially displaced joint forces over a relatively large area, and the elliptic cross-section yields high bending resistance in the frontal plane. A human-like angle of obliquity is present in the early australopithecines, the values being mostly within the range of variation of children. The valgus position of the australopithecine knee joint is considered to be a functional, and epigenetic consequence of habitual bipedality. It is particularly pronounced because of the short length of the femur and the great bitrochanteric width.

ISSN:0015-5713    

DOI:10.1159/000157187

出版商:S. Karger AG    

年代:1996

数据来源: Karger