Reconstruction of the STS 14 (Australopithecus africanus) pelvis

The study reports a reconstruction of the sacrum in STS 14 based on extrapolation from the measurements of the first two sacral vertebrae of STS 14 and of the angle formed by the anterior surfaces of their vertebral bodies. Reconstruction is based on comparisons of, and extrapolation from, sacra of Pan troglodytes, Homo sapiens, and Australopithecus afarensis. The reconstructed sacrum has an anterior sacral curvature of 39°. The two ossa coxae were also completed by mirror imaging of one side by the other. With the pelvis completely reconstructed, the pelvic dimensions for the antero-posterior (AP) diameters of the pelvic inlet, midpelvis, and pelvic outlet are 85, 68, and 69 mm and the corresponding transverse (TR) diameters are 109, 88, and 103 mm, respectively. The posterior sagittal diameters in the three pelvic planes are small compared to the anterior sagittal diameters. This analysis indicates that the STS 14 pelvis is platypelloid in the three pelvic planes; i.e., all the AP diameters are smaller than the corresponding TR diameters. This makes the STS 14 pelvis similar to that to Al 288-1, save for a less pronounced degree of platypelloidy at the inlet in the former. © 1995 Wiley-Liss, Inc.     

Effects of size and locomotor adaptations on the hominid pelvis: evaluation of australopithecine bipedality with a new multivariate method

Three pelves and eight innominate bones belonging to the fossil species, Australopithecus africanus, Australopithecus robustus, Homo erectus, and Homo sapiens, have been studied biometrically and compared with those of recent humans and apes. A new method of logarithmic factorial analysis suppresses both the size effects and the size reference on pelvic proportions. In combination with principal component analysis it allows specializations to be dissociated from allometrical variations. Some morphological differences on the hominid pelvis prove to be mainly allometric. However, the pelvic morphology of australopithecines is clearly differentiated from that of the genus Homo (including H. erectus, OH 28, KNMER 3227). A. africanus (Sts 14, MLD 7, AL 288) is nearer the humans than is A. robustus (SK 50, SK 3155), which appears to be more specialized in the australopithecine lineage. The pelvic morphology of A. africanus, as integrated with the articular pelvic-femoral link, appears to be biometrically equivalent to that of humans.     

Description d’un bassin fragmentaire de Paranthropus robustus du site Plio-Pléistocène de Drimolen (Afrique du Sud)

The Plio-Pleistocene site of Drimolen (Gauteng Province, South Africa) has yielded a fragmentary adult pelvis, DNH 43, composed of a robust, right innominate bone (DNH 43B) associated with the sacrum and the posterior arch of the last lumbar vertebra (DNH 43 A). Comparisons with other Plio-Pleistocene hominids (AL 288.1, Sts 14, Sts 65, Stw 431, TM 1605, SK 50, SK 3155b) pelves have been made which indicate that this specimen belongs to Paranthropus robustus. The ilium of the Drimolen hominid is narrowed just above the acetabulum. The small auricular surface is set far away from the acetabulum. The sacrum is curved, the upper lateral angles are clearly expressed. Some anatomical features reveal a lumbar lordosis in DNH 43. This lumbar lordosis is specific of australopithecines because different from extant human.     

Heterochronic processes in human evolution: An ontogenetic analysis of the hominid pelvis

Changes in pelvic shape in human ontogeny and hominid phylogeny suggest that the heterochronic processes involved differ greatly from the neotenic process traditionally described in the evolution of the skull. The morphology of 150 juvenile and adult pelves of African apes, 60 juvenile and adult pelves of modern humans, two adult pelves and a juvenile hip bone of australopithecines (Sts 14, AL 288, MLD 7) was studied. Multivariate results, ontogenetic allometries, and growth curves confirm that the pelvic growth pattern in humans differs markedly from those of the African apes. The results permit the following conclusions. First, the appearance of a new feature (acetabulo-cristal buttress and cristal tubercle) at the time of human birth allows the addition of traits, such as the attainment of a proportionally narrower pelvis, with more sagittally positioned iliac blades. Pelvic proportions and orientation change progressively in early childhood as bipedalism is practiced. Other changes in pelvic proportions occur later with the adolescent growth spurt. Second, comparison of juvenile and adult australopithecines to modern humans indicates that 1) some pelvic traits of adult Australopithecus resemble those of neonate Homo; 2) the pelvic growth of Australopithecus was probably closer to that of apes, than to that of humans; and 3) prolonged growth in length of hindlimb and pelvis after sexual maturity seems to be a unique feature of Homo. The position of the acetabulo-cristal buttress and of the cristal tubercle on the ilium are similar in adult Australopithecus and neonate Homo suggesting that this feature may have been displaced later during hominid evolution. Progressive displacement of the acetabulo-cristal buttress on the ilium occurs both during hominid evolution (from Australopithecus to Homo sapiens) and human growth (from neonate to adult). This suggests peramorphic evolution of the pelvic morphology of hominids combining three processes of recapitulation (pre-displacement, acceleration and time hypermorphosis). The results lend credence to the hypothesis that no single heterochronic process accounts for all human evolutionary change; rather this reflects a combination of relative changes in growth rhythm and duration, including other perturbations, such as the appearance of new morphological features. Am J Phys Anthropol 105:441–459, 1998. © 1998 Wiley-Liss, Inc.     

Ontogeny and evolution of pelvic diameters in anthropoid primates and in Australopithecus afarensis (AL 288-1)

Pelvic diameters (both anteroposterior [AP] and transverse [TR]) were investigated in a series of anthropoid primates. The ratio of diameters (AP/TR) in each of three pelvic planes (inlet, midpelvis, and outlet) was calculated. In addition to the above, the length of the iliac, pubic, and ischial axes and the angles between these axes were determined. The AP/TR ratio at the pelvic inlet is (reported in millimeters, +/- SD, unless otherwise specified) 1.81 +/- 0.27 in New World monkeys (Cebidae) and Macaca mulatta; 1.53 +/- 0.17 in hylobatids and pongids; 0.87 +/- 0.08 in Homo sapiens; and 0.58 in Australopithecus afarensis (AL 288-1). The AP/TR ratio in the midpelvis is 1.61 +/- 0.23 in nonhominid primates (Cebidae, M. mulatta, hylobatids, and pongids), 1.12 +/- 0.11 in humans, and 0.59 in AL 288-1. In monkeys (Cebidae and M. mulatta), hylobatids, pongids, H. sapiens, and AL 288-1, the ratios of the length of the pubic axis over the ischial axis were 0.84 +/- 0.06, 0.95 +/- 0.07, 1.10 +/- 0.15, and 1.46, respectively; the pubis-ilium angles were 96 +/- 11, 120 +/- 10, 131 +/- 11, and 147 degrees, respectively; and the ischium-pubis angles were 106 +/- 11, 86 +/- 8, 96 +/- 7, and 68 degrees, respectively. In none of these pelvic features was AL 288-1 "intermediate" between pongids and H. sapiens. The anatomical peculiarities of the pelvis in AL 288-1 are explained primarily as the result of early adaptation to erect posture, which resulted in the reduction of the distance between the sacroiliac joint and the hip joint. As a consequence, the sacral promontory moved toward the pubic symphysis, and this resulted in shortening of the AP diameter and widening of the TR diameter at the pelvic inlet.     

Evolution of the ischial spine and of the pelvic floor in the Hominoidea

Study of the pelvis in 143 different mammals reveals that in quadrupeds the ischial spines are barely noticeable and are located posteriorly near the sacrum. In humans, the ischial spines are prominent and more anteriorly located. As a consequence of their position and size, the ischial spines in humans become an obstacle to parturition. Herein a theory is proposed to account for what appears to be an incongruous development and orientation of the ischial spines in humans. The pelvic diaphragm is a vertical pelvic "wall" in tailed mammals and is composed of muscles involved mostly with the motion of the tail. In humans, the muscles of the pelvic diaphragm have a very different anatomical orientation. They form a horizontal pelvic "floor," and their functions are first to support the abdominopelvic organs and resist intra-abdominal pressure that is exerted from above, and second, as levator ani, to control the anal sphincter. In humans the muscles and fascias of the pelvic diaphragm are inserted on the ischial spines either directly or indirectly through the sacrospinous ligament and the tendinous arch of the pelvic fascia. The result is a medial pull on the ischial spines to produce a more rigid and narrower pelvic floor. An inconstant ossification center for the ischial spines make them more prominent. The backward tilt of the sacrum placed the bispinal line in a diameter position. Pongids and even fossil hominids occupy an intermediate position between tailed mammals and Homo sapiens. The present form of the pelvis in Homo sapiens may be determined by a significant genetic component but may also be partly acquired during childhood and adolescence.     

Sexual dimorphism in the human bony pelvis, with a consideration of the Neandertal pelvis from Kebara Cave, Israel.

Sexual dimorphism of the human pelvis is inferentially related to obstetrics. However, researchers disagree in the identification and obstetric significance of pelvic dimorphisms. This study addresses three issues. First, common patterns in dimorphism are identified by analysis of pelvimetrics from six independent samples (Whites and Blacks of known sex and four Amerindian samples of unknown sex). Second, an hypothesis is tested that the index of pelvic dimorphism (female mean x 100/male mean) is inversely related to pelvic variability. Third, the pelvic dimensions of the Neandertal male from Kebara cave, Israel are compared with those of the males in this study. The results show that the pelvic inlet is the plane of least dimorphism in humans. The reason that reports often differ in the identification of dimorphisms for this pelvic plane is that both the length of the pubis and the shape of the inlet are related to nutrition. The dimensions of the pelvis that are most dimorphic (that is, female larger than male) are the measures of posterior space, angulation of sacrum, biischial breadth, and subpubic angle. Interestingly, these dimensions are also the most variable. The hypothesis that variability and dimorphism are inversely related fails to be supported. The factors that influence pelvic variability are discussed. The Kebara 2 pelvis has a spacious inlet and a confined outlet relative to modern males, though the circumferences of both planes in the Neandertal are within the range of variation of modern males. The inference is that outlet circumference in Neandertal females is also small in size, but within the range of variation of modern females. Arguments that Neandertal newborns were larger in size than those of modern humans necessarily imply that birth was more difficult in Neandertals.     

基于CT薄层扫描的骨盆数字化三维模型的分色构建

目的：探讨利用CT原始数据集对骨盆进行数字化三维分色构建的方法及意义。方法：选择1例因宫颈癌行盆腔CT薄层扫描患者的Dicom3．0原始二维断层数据集,利用Mimics10．01软件行骨盆三维分色重建。结果：构建的数字化三维分色模型形态规则、清晰逼真、立体感强、解剖清晰,不仅可以对构成骨盆的髂骨、骶骨及尾骨进行单独的三维分色显示,而且可以进行任意角度、距离的融合分离显示,更有利于对骨盆进行精细地全面立体观察分析。结论：基于CT薄层扫描数据集构建骨盆三维分色模型的方法简单、可行,是指导临床及教学的好工具。     

Multivariate analysis of the sexual dimorphism of the hip bone in a modern human population and in early hominids

A large sample of hip bones of known sex coming from one modern population is studied morphologically and by multivariate analysis to investigate sexual dimorphism patterns. A principal component analysis of raw data shows that a large amount of the hip bone sexual dimorphism is accounted for by size differences, but that sex-linked shape variation is also very conspicuous and cannot be considered an allometric consequence of differences in body size between the sexes. The PCA of transformed (“shape”) variables indicates that the female hip bones are different in those traits associated with a relatively larger pelvic inlet (longer pubic bones, a greater degree of curvature of the iliopectineal line, and a more posterior position of the auricular surface), as well as a broader sciatic notch. The analysis of nonmetric traits also shows marked sexual dimorphism in the position of the sacroiliac joint in the iliac bone, in the shape of the sciatic notch, in pubic morphology, and in the presence of the pre-auricular sulcus in females. When the australopithecine AL 288-1 and Sts 14 hip bones are included in the multivariate analysis, they appear as “ultra-females.” In particular these early hominids exhibit extraordinarily long pubic bones and iliopectineal lines, which cannot be explained by allometry. © 1994 Wiley-Liss, Inc.     

“Lucy” (A.L. 288‐1) had five sacral vertebrae

A “long‐backed” scenario of hominin vertebral evolution posits that early hominins possessed six lumbar vertebrae coupled with a high frequency of four sacral vertebrae (7:12‐13:6:4), a configuration acquired from a hominin‐panin last common ancestor (PLCA) having a vertebral formula of 7:13:6‐7:4. One founding line of evidence for this hypothesis is the recent assertion that the “Lucy” sacrum (A.L. 288‐1an, Australopithecus afarensis) consists of four sacral vertebrae and a partially‐fused first coccygeal vertebra (Co1), rather than five sacral vertebrae as in modern humans. This study reassesses the number of sacral vertebrae in Lucy by reexamining the distal end of A.L.288‐1an in the context of a comparative sample of modern human sacra and Co1 vertebrae, and the sacrum of A. sediba (MH2). Results demonstrate that, similar to S5 in modern humans and A. sediba, the last vertebra in A.L. 288‐1an exhibits inferiorly‐projecting (right side) cornua and a kidney‐shaped inferior body articular surface. This morphology is inconsistent with that of fused or isolated Co1 vertebrae in humans, which either lack cornua or possess only superiorly‐projecting cornua, and have more circularly‐shaped inferior body articular surfaces. The level at which the hiatus' apex is located is also more compatible with typical five‐element modern human sacra and A. sediba than if only four sacral vertebrae are present. Our observations suggest that A.L. 288‐1 possessed five sacral vertebrae as in modern humans; thus, sacral number in “Lucy” does not indicate a directional change in vertebral count that can provide information on the PLCA ancestral condition. Am J Phys Anthropol 156:295–303, 2015. © 2014 Wiley Periodicals, Inc.     

Descriptions of the lower limb skeleton of Homo floresiensis

Bones of the lower extremity have been recovered for up to nine different individuals of Homo floresiensis - LB1, LB4, LB6, LB8, LB9, LB10, LB11, LB13, and LB14. LB1 is represented by a bony pelvis (damaged but now repaired), femora, tibiae, fibulae, patellae, and numerous foot bones. LB4/2 is an immature right tibia lacking epiphyses. LB6 includes a fragmentary metatarsal and two pedal phalanges. LB8 is a nearly complete right tibia (shorter than that of LB1). LB9 is a fragment of a hominin femoral diaphysis. LB10 is a proximal hallucal phalanx. LB11 includes pelvic fragments and a fragmentary metatarsal. LB13 is a patellar fragment, and LB14 is a fragment of an acetabulum. All skeletal remains recovered from Liang Bua were extremely fragile, and some were badly damaged when they were removed temporarily from Jakarta. At present, virtually all fossil materials have been returned, stabilized, and hardened. These skeletal remains are described and illustrated photographically. The lower limb skeleton exhibits a uniquely mosaic pattern, with many primitive-like morphologies; we have been unable to find this combination of ancient and derived (more human-like) features in either healthy or pathological modern humans, regardless of body size. Bilateral asymmetries are slight in the postcranium, and muscle markings are clearly delineated on all bones. The long bones are robust, and the thickness of their cortices is well within the ranges seen in healthy modern humans. LB1 is most probably a female based on the shape of her greater sciatic notch, and the marked degree of lateral iliac flaring recalls that seen in australopithecines such as “Lucy” (AL 288-1). The metatarsus has a human-like robusticity formula, but the proximal pedal phalanges are relatively long and robust (and slightly curved). The hallux is fully adducted, but we suspect that a medial longitudinal arch was absent.     

Underestimating intraspecific variation: The problem with excluding Sts 19 from Australopithecus africanus

Two analyses conclude that Sts 19 cannot be accommodated within the Australopithecus africanus hypodigm (Kimbel and Rak [1993] In Kimbel and Martin [eds.]: Species, Species Concepts, and Primate Evolution. New York: Plenum, pp. 461–484; Sarmiento [1993] Am. J. Phys. Anthropol. [Suppl.] 16:173). Both studies exclude Sts 19 because it possesses synapomorphies with Homo. Furthermore, according to Kimbel and Rak (1993), including Sts 19 in A. africanus results in an unacceptably high degree of polymorphism. This study aims to refute the null hypothesis that Sts 19 belongs to A. africanus. Twelve basicranial characters, as defined and implemented in Kimbel and Rak's study, were scored for casts of seven A. africanus and seven Homo habilis basicranial specimens. These characters were also examined on specimens from a large (N = 87) sample of African pongids. Contrary to Kimbel and Rak's (1993) findings, the null hypothesis is not refuted. The degree of polymorphism among A. africanus with Sts 19 included is less than that seen in Pan troglodytes. In addition, Sts 19 shares only one apomorphy with Homo. However, when treated metrically, Sts 19's morphology for this character is not significantly divergent from other A. africanus specimens. Am J Phys Anthropol 105:461–480, 1998. © 1998 Wiley-Liss, Inc.     

Sacral curvature and supine posture

Sacral curvature (SC), represented by the angle between the first and the last sacral vertebrae, is a feature that differentiates the human pelvis from that of other animals. The sacral curvature was measured and studied in 14 cebids, 31 cercopithecids, 17 hylobatids, 85 pongids, 23 normal human children, 15 children with orthopedic handicaps, 49 normal adult human males, and 64 normal adult human females. Sacral curvature was minimal to nil in monkeys (mean 11.5 +/- 6 SD degrees), and moderate in apes (hylobatids, mean 16 +/- 10 SD degrees; pongids, mean 27.2 +/- 16 SD degrees). In human newborns SC is minimal, increasing progressively until adolescence, reaching a mean of 64.7 +/- 29 SD degrees in adult humans. This study investigates the different factors contributing to the formation of the sacral curvature. These factors include 1) the effect of erect posture, which tilts the upper part of the sacrum dorsally and the lower part of the sacrum ventrally, and 2) the influence of supine posture, which affects the development of the lower part of the sacrum. In addition to supine posture the levator ani, which is well developed in Homo sapiens, also affects the lower part of the sacrum and coccyx and influences its ventral orientation. Variation in SC can result from differences in onset and frequency of supine posture. This is the first time that supine posture has been shown to play a role in shaping the human pelvis, although it is as characteristic of H. sapiens as is erect posture.     

Le bassin de l’homme du Pléistocène supérieur de Liujiang, Sud de la Chine : taille du corps, forme du corps et encéphalisation

The Late Pleistocene hominin fossil assemblage from Liujiang, South China include a fairly well-preserved cranium, a right os coxa, a complete sacrum, and other postcranial elements all belonging to a single individual. This rare discovery offers us a unique and singular opportunity in understanding this Late Pleistocene hominin's body proportion and relative cranial capacity (encephalization quotient [EQ]), and also pelvic morphology. Using the available right innominate and its mirror-imaged left side, we reconstruct Liujiang hominin's pelvis. Our analysis of the pelvis indicates that the Liujiang hominin has a very gracile and modern-like pelvic morphology. Indeed, all of the pelvic dimensions are smaller than those of other Pleistocene hominins. Moreover, the pelvic characteristics typical of Middle and Late Pleistocene hominins including Neanderthals cannot be identified in the Liujiang pelvis. In contrast, both Liujiang's metric and non-metric features indicate affinities to more recent human populations including our modern Chinese collections from Guangxi of south China. Further support of this assessment comes from the EQ value of 5.754 for Liujiang which is closer to Minatogawa 2 and modern Chinese populations than to Middle and Late Pleistocene fossil hominins. Our analysis of body shape shows that Liujiang has body proportion (i.e. body height relative to body breadth) typical of warm-adapted populations. Based on these findings, we reason that the modern physical characteristics of Liujiang may allude to a more recent geological age. Alternatively, its morphological “modernity” could also point to a much higher degree of skeletal variation within Late Pleistocene hominins in East Asia.     

Brief Communication: Lumbar lordosis in extinct hominins: Implications of the pelvic incidence

Recently, interest has peaked regarding the posture of extinct hominins. Here, we present a new method of reconstructing lordosis angles of extinct hominin specimens based on pelvic morphology, more specifically the orientation of the sacrum in relation to the acetabulum (pelvic incidence). Two regression models based on the correlation between pelvic incidence and lordosis angle in living hominoids have been developed. The mean values of the calculated lordosis angles based on these models are 36°?45° for australopithecines, 45°?47° for Homo erectus, 27°?34° for the Neandertals and the Sima de los Huesos hominins, and 49°?51° for fossil H. sapiens. The newly calculated lordosis values are consistent with previously published values of extinct hominins (Been et al.: Am J Phys Anthropol 147 (2012) 64–77). If the mean values of the present nonhuman hominoids are representative of the pelvic and lumbar morphology of the last common ancestor between humans and nonhuman hominoids, then both pelvic incidence and lordosis angle dramatically increased during hominin evolution from 27° ± 5 to 22° ± 3 (respectively) in nonhuman hominoids to 54° ± 10 and 51° ± 11 in modern humans. This change to a more human‐like configuration appeared early in the hominin evolution as the pelvis and spines of both australopithecines and H. erectus show a higher pelvic incidence and lordosis angle than nonhuman hominoids. The Sima de los Huesos hominins and Neandertals show a derived configuration with a low pelvic incidence and lordosis angle. Am J Phys Anthropol 154:307–314, 2014. © 2014 Wiley Periodicals, Inc.     

Pelvic function in anuran jumping: Interspecific differences in the kinematics and motor control of the iliosacral articulation during take‐off and landing

Although the anuran pelvis is thought to be adapted for jumping, the function of the iliosacral joint has seen little direct study. Previous work has contrasted the basal “ lateral‐bender ” pelvis from the “ rod‐like ” pelvis of crown taxa hypothesized to function as a sagittal hinge to align the trunk with take‐off forces. We compared iliosacral movements and pelvic motor patterns during jumping in the two pelvic types. Pelvic muscle activity patterns, iliosacral anteroposterior (AP) movements and sagittal bending of the pelvis during the take‐off and landing phases were quantified in lateral bender taxa Ascaphus (Leiopelmatidae) and Rhinella (Bufonidae) and the rod‐like Lithobates (Ranidae). All three species exhibit sagittal extension during take‐off, therefore, both pelvic types employ a sagittal hinge. However, trunk elevation occurs significantly earlier in the anuran rod‐like pelvis. Motor patterns confirm that the piriformis muscles depress the urostyle while the longissimus dorsi muscles elevate the trunk during take‐off. However, the coccygeoiliacus muscles also produce anterior translation of the sacrum on the ilia. A new model illustrates how AP translation facilitates trunk extension in the lateral‐bender anurans that have long been thought to have limited sagittal bending. During landing, AP translation patterns are similar because impact forces slide the sacrum from its posterior to anterior limits. Sagittal flexion during landing differs among the three taxa depending on the way the species land. AP translation during landing may dampen impact forces especially in Rhinella in which pelvic function is tuned to forelimb‐landing dynamics. The flexibility of the lateral‐bender pelvis to function in sagittal bending and AP translation helps to explain the retention of this basal configuration in many anurans. The novel function of the rod‐like pelvis may be to increase the rate of trunk elevation relative to faster rates of energy release from the hindlimbs enabling them to jump farther. J. Morphol. 277:1539–1558, 2016. © 2016 Wiley Periodicals, Inc.     

Bony pelvic canal size and shape in relation to body proportionality in humans

Obstetric selection acts on the female pelvic canal to accommodate the human neonate and contributes to pelvic sexual dimorphism. There is a complex relationship between selection for obstetric sufficiency and for overall body size in humans. The relationship between selective pressures may differ among populations of different body sizes and proportions, as pelvic canal dimensions vary among populations. Size and shape of the pelvic canal in relation to body size and shape were examined using nine skeletal samples (total female n = 57; male n = 84) from diverse geographical regions. Pelvic, vertebral, and lower limb bone measurements were collected. Principal component analyses demonstrate pelvic canal size and shape differences among the samples. Male multivariate variance in pelvic shape is greater than female variance for North and South Africans. High‐latitude samples have larger and broader bodies, and pelvic canals of larger size and, among females, relatively broader medio‐lateral dimensions relative to low‐latitude samples, which tend to display relatively expanded inlet antero‐posterior (A‐P) and posterior canal dimensions. Differences in canal shape exist among samples that are not associated with latitude or body size, suggesting independence of some canal shape characteristics from body size and shape. The South Africans are distinctive with very narrow bodies and small pelvic inlets relative to an elongated lower canal in A‐P and posterior lengths. Variation in pelvic canal geometry among populations is consistent with a high degree of evolvability in the human pelvis. Am J Phys Anthropol 151:88–101, 2013. © 2013 Wiley Periodicals, Inc.     

Four‐dimensional analysis of early pelvic girdle development in Rana temporaria

A key event in vertebrate evolution is the linkage of the appendicular to the axial skeleton. The present study investigates the developmental dynamics of pelvic girdle morphogenesis in Rana temporaria up until metamorphosis, with respect to its functional and spatio‐temporal organization. The main questions to be addressed are: initial location and the number of elements contributing to pelvic girdle formation, mechanism of bridging between the pelvic anlage and the sacrum and arthrogenesis. Serial histological sections of specimens from Gosner Stages 30 to 41 were bright‐field microscopically examined and 3D‐reconstructed. 3D‐models were merged to 4D‐animations illustrating the complex developmental dynamics through time. The results reveal the initial formation of a single mesenchymal condensation located close to the appendicular skeleton, but far from the axial skeleton. In addition, our analysis detects a thin connective tissue strand in R. temporaria guiding the elongation of the ilium towards the sacrum. The 4D‐visualization allows novel insight into the ilio‐sacral bridging process and the reorientation of the pelvis. J. Morphol., 2011. © 2010 Wiley‐Liss, Inc.     

Modeling three-dimensional sculptures of australopithecines (Australopithecus afarensis) for the Museum of Natural History of Vienna (Austria): the post-cranial hypothesis.

In March 1999, E. Daynes, a sculptor specializing in fossil hominid reconstruction, asked C. Berge to take over the scientific supervision of the reconstruction of two australopithecine post-crania. The heads had been modeled from two skulls found in Hadar (AL 444-2, AL 417). The sculptures were to be represented in a walking stance. The female proportions (AL 417) are estimated from the skeleton of 'Lucy' (AL 288), and the male proportions (AL 444-2) extrapolated from the female ones. Biomechanical and anatomical data (comparison with great apes and humans) are used to reconstruct both dynamic equilibrium and muscular systems. The reconstruction suggests that the fossils moved the pelvis and shoulders extensively when they walked. The hindlimb muscles (such as adductors, gluteal muscles and calf) are fleshy and not or very little tendinous. As indicated by the Laetoli step prints (belonging to a close and contemporaneous species), the foot is adducted during the walk and the support is internal just before take off. In spite of inevitable approximations, such a reconstruction appears to be particularly helpful to bring out morphological and functional traits of the first hominids which are both close to and different from modern humans.     

Like Father,Like Son: Assessment of the Morphological Affinities of A.L. 288–1 (A. afarensis), Sts 7 (A. africanus) and Omo 119–73–2718 (Australopithecus sp.) through a Three-Dimensional Shape Analysis of the Shoulder Joint

The postcranial evidence for the Australopithecus genus indicates that australopiths were able bipeds; however, the morphology of the forelimbs and particularly that of the shoulder girdle suggests that they were partially adapted to an arboreal lifestyle. The nature of such arboreal adaptations is still unclear, as are the kind of arboreal behaviors in which australopiths might have engaged. In this study we analyzed the shape of the shoulder joint (proximal humerus and glenoid cavity of the scapula) of three australopith specimens: A.L. 288–1 (A. afarensis), Sts 7 (A. africanus) and Omo 119–73–2718 (Australopithecus sp.) with three-dimensional geometric morphometrics. The morphology of the specimens was compared with that of a wide array of living anthropoid taxa and some additional fossil hominins (the Homo erectus specimen KNM-WT 15000 and the H. neanderthalensis specimen Tabun 1). Our results indicate that A.L. 288–1 shows mosaic traits resembling H. sapiens and Pongo, whereas the Sts 7 shoulder is most similar to the arboreal apes and does not present affinities with H. sapiens. Omo 119–73–2718 exhibits morphological affinities with the more arboreal and partially suspensory New World monkey Lagothrix. The shoulder of the australopith specimens thus shows a combination of primitive and derived traits (humeral globularity, enhancement of internal and external rotation of the joint), related to use of the arm in overhead positions. The genus Homo specimens show overall affinities with H. sapiens at the shoulder, indicating full correspondence of these hominin shoulders with the modern human morphotype.