RESUMEN
Gestational growth and development of bone is an understudied process compared to soft tissues and has implications for lifelong health. This study investigated growth and development of human fetal limb bone trabecular architecture using 3D digital histomorphometry of microcomputed tomography data from the femora and humeri of 35 skeletons (17 female and 18 male) with gestational ages between 4 and 9 months. Ontogenetic data revealed: (i) fetal trabecular architecture is similar between sexes; (ii) the proximal femoral metaphysis is physically larger, with thicker trabeculae and greater bone volume fraction relative to the humerus, but other aspects of trabecular architecture are similar between the bones; (iii) between 4 and 9 months gestation there is no apparent sexual or limb dimorphism in patterns of growth, but the size of the humerus and femur diverges early in development. Additionally, both bones exhibit significant increases in mean trabecular thickness (and for the femur alone, bone volume fraction) but minimal trabecular reorganisation (i.e., no significant changes in degree of anisotropy, connectivity density, or fractal dimension). Overall, these data suggest that in contrast to data from the axial skeleton, prenatal growth of long bones in the limbs is characterised by size increase, without major reorganizational changes in trabecular architecture.
Asunto(s)
Hueso Esponjoso , Fémur , Microtomografía por Rayos X , Humanos , Femenino , Masculino , Hueso Esponjoso/diagnóstico por imagen , Hueso Esponjoso/crecimiento & desarrollo , Fémur/diagnóstico por imagen , Fémur/crecimiento & desarrollo , Fémur/embriología , Fémur/anatomía & histología , Feto , Húmero/crecimiento & desarrollo , Húmero/diagnóstico por imagen , Húmero/embriología , Húmero/anatomía & histología , Desarrollo Óseo , Edad Gestacional , Desarrollo Fetal/fisiologíaRESUMEN
Recent discoveries of Homo floresiensis and H. luzonensis raise questions regarding how extreme body size reduction occurred in some extinct Homo species in insular environments. Previous investigations at Mata Menge, Flores Island, Indonesia, suggested that the early Middle Pleistocene ancestors of H. floresiensis had even smaller jaws and teeth. Here, we report additional hominin fossils from the same deposits at Mata Menge. An adult humerus is estimated to be 9 - 16% shorter and thinner than the type specimen of H. floresiensis dated to ~60,000 years ago, and is smaller than any other Plio-Pleistocene adult hominin humeri hitherto reported. The newly recovered teeth are both exceptionally small; one of them bears closer morphological similarities to early Javanese H. erectus. The H. floresiensis lineage most likely evolved from early Asian H. erectus and was a long-lasting lineage on Flores with markedly diminutive body size since at least ~700,000 years ago.
Asunto(s)
Evolución Biológica , Tamaño Corporal , Fósiles , Hominidae , Diente , Animales , Hominidae/anatomía & histología , Indonesia , Diente/anatomía & histología , Húmero/anatomía & histología , FilogeniaRESUMEN
Stature estimation is a core component to the biological profile in forensic anthropology casework. Here we provide mathematical equations for estimating stature for contemporary American Indians (AI), which currently are lacking in forensic anthropology. Drawing on postmortem computed tomography data from the New Mexico Decedent Image Database we regressed cadaveric length on four long bone length measures of the tibia, femur, and humerus to produce 11 combinations of models. Separate regression models were calculated for the entire pooled sample, by sex, broad AI language groups, and age + sex subsamples and compared. Sex-specific models were statistically better than general models, which were more accurate than language group and age + sex models. Equations were created for general and sex-specific models. Application to an independent test sample demonstrates the equations are accurate for stature estimation with overestimates of less than 1â¯cm. The equations provide similar levels of precision to stature estimation programs like the FORDISC 3.0 module and other stature equations in the literature. We provide recommendations for equation use in casework based on our results. These equations are the first for estimating stature in contemporary AI. This paper demonstrates the appropriateness of these newly created stature equations for use in New Mexico and the surrounding region.
Asunto(s)
Estatura , Antropología Forense , Indígenas Norteamericanos , Humanos , Antropología Forense/métodos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Anciano , Adulto Joven , Análisis de Regresión , Fémur/anatomía & histología , Fémur/diagnóstico por imagen , New Mexico , Tibia/anatomía & histología , Tibia/diagnóstico por imagen , Húmero/anatomía & histología , Húmero/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Anciano de 80 o más Años , Adolescente , Sudoeste de Estados UnidosRESUMEN
This study aimed to assess the fusion of growth plates and the development of secondary ossification centres in the forelimb bones of maned wolves (Chrysocyon brachyurus), contrasting the findings with established data from domestic dogs. Three maned wolves, comprising one male and two females, initially aged between 3 and 4 months, were subjected to monthly radiographic evaluations until 10-11 months of age, followed by bimonthly assessments until 18-19 months of age, encompassing both forelimbs. The closure times of growth plates were observed as follows: supraglenoid tubercle (7-8 months), proximal humerus (17-19 months), distal humerus (8-9 months), medial epicondyle of the humerus (8-9 months), proximal ulna (9-10 months), proximal radius (13-15 months), distal ulna (13-15 months) and distal radius (17-19 months). Statistical analysis revealed significant differences in the areas of secondary ossification centres in the proximal epiphyses of the humerus and radius, respectively, observed from the initial evaluation at 8-9 months and 6-7 months. Conversely, the epiphyses of the supraglenoid tubercle, distal humerus, proximal ulna, distal ulna, medial epicondyle of the humerus and distal radius did not exhibit significant area differences between 3-4 months and 4-5 months, yet notable distinctions emerged at 5-6 months. In summary, while the radiographic appearance of epiphyseal growth plates and secondary ossification centres in maned wolves resembles that of domestic dogs, closure times vary. These findings contribute to understanding the dynamics of epiphyseal growth plates in this species.
Asunto(s)
Desarrollo Óseo , Canidae , Miembro Anterior , Húmero , Radio (Anatomía) , Cúbito , Animales , Miembro Anterior/anatomía & histología , Miembro Anterior/diagnóstico por imagen , Masculino , Femenino , Canidae/anatomía & histología , Radio (Anatomía)/diagnóstico por imagen , Radio (Anatomía)/anatomía & histología , Radio (Anatomía)/crecimiento & desarrollo , Cúbito/diagnóstico por imagen , Cúbito/anatomía & histología , Cúbito/crecimiento & desarrollo , Desarrollo Óseo/fisiología , Húmero/anatomía & histología , Húmero/diagnóstico por imagen , Húmero/crecimiento & desarrollo , Placa de Crecimiento/diagnóstico por imagen , Placa de Crecimiento/anatomía & histología , Placa de Crecimiento/crecimiento & desarrollo , Radiografía/veterinaria , Osteogénesis/fisiología , Perros/anatomía & histología , Perros/crecimiento & desarrolloRESUMEN
PURPOSE: This study shows the danger zone and the safety corridor in the lateral approach with bridge plating by measuring the distance between the lateral side of the plate positioned on the lateral aspect of the humerus and the radial nerve after it pierces the lateral intermuscular septum, in the different forearm positions. METHODS: Forty arms of 20 human cadavers were used, the radial nerve was identified and marked on the lateral surface the radial nerve at the exit of the lateral intermuscular septum and anteriorisation of the nerve in relation to the humeral shaft and the lateral epicondyle was also marked. The distances were measured with a digital caliper. A submuscular extraperiosteal corridor was created, proximally between the biceps brachialis and deltoid muscle and distally between the triceps and brachioradialis muscle, followed by the positioning of the low contact large fragments contoured plate with 14 combined holes (fixed and cortical angle), inserted from distal to proximal. Measurements were performed in four positions (elbow flexion with forearm pronation, elbow flexion with forearm supination, elbow extension with forearm pronation and elbow extension with forearm supination). RESULTS: Significant statistical differences occurred with the different positions, and the elbow flexion with forearm supination was shown to be the position that provides the safest submuscular extraperiosteal corridor in a lateral approach of the humerus. CONCLUSION: The danger zone of radial nerve is an area that extends from 15 cm to 5 cm proximal to the lateral epicondyle and the safest way to create a submuscular and extraperiosteal corridor in the lateral region of the humerus is with the elbow in flexion and the forearm in supination.
Asunto(s)
Placas Óseas , Cadáver , Fijación Interna de Fracturas , Húmero , Nervio Radial , Humanos , Nervio Radial/anatomía & histología , Masculino , Húmero/anatomía & histología , Femenino , Fijación Interna de Fracturas/métodos , Fijación Interna de Fracturas/efectos adversos , Anciano , Fracturas del Húmero/cirugía , Anciano de 80 o más Años , Antebrazo/anatomía & histología , Persona de Mediana EdadRESUMEN
The long, gracile morphology of the limb bones of the Late Miocene hyaenid Ictitherium ebu has led to the hypothesis that this animal was cursorial. The forelimb and femur of the holotype were compared with specimens of extant Hyaenidae and Canidae. Two morphometric methods were used. The first used measurements to calculate indices of different morphological characters. The second method involved capturing photographs of the anterior distal humerus of each specimen, mapping six landmarks on them, and calculating truss distances. These distances represent a schematic reproduction of the elbow. Multivariate statistical analysis primarily separated the data based on taxonomy, yet locomotor and habitat categories were also considered. Ictitherium ebu has an overall morphology similar to that of the maned wolf and a distal humerus reminiscent of that of the aardwolf. The long, gracile limb bones of I. ebu are suggested to be adaptations for pouncing on prey, for locomotor efficiency, and for looking over the tall grass of the open environments the animal lived in, much like the present-day maned wolf.
Asunto(s)
Miembro Anterior , Fósiles , Animales , Kenia , Miembro Anterior/anatomía & histología , Fémur/anatomía & histología , Húmero/anatomía & histología , Locomoción/fisiologíaRESUMEN
The bicipital groove is a groove on the anterior aspect of the proximal end of the humerus. It lies between the greater and lesser tubercles. The variations of this groove may lead to various pathologies of the biceps brachii tendon, one of the most common causes of shoulder pain. Hence, this study examines the various osteometric parameters of bicipital groove in the Bangladeshi population. This cross-sectional descriptive study was done on 100 dry adult human cadaveric humeri (43 right sides and 57 left sides) in the Department of Anatomy, Mymensingh Medical College, Bangladesh from July 2021 to June 2022. The length, maximum width and depth of the bicipital groove and the length of this groove's medial and lateral walls were measured using a digital Vernier slide caliper. Data were recorded in a predesigned data sheet separately and analyzed statistically using Microsoft Excel and SPSS. According to the present study, the mean±SD length of the bicipital groove of the right humeri was 66.646±11.563mm and the left humeri were 66.002±13.025mm. The mean±SD maximum width of the bicipital groove of the right humeri was 10.870±1.799mm and the left humeri were 11.480±1.402mm. The mean±SD depth of the bicipital groove of the right humeri was 4.242±0.655mm and the left humeri were 4.452±0.854mm. The mean±SD medial wall length of the bicipital groove of the right humeri was 60.671±12.360mm and the left humeri were 59.161±13.660mm. The mean±SD lateral wall length of the bicipital groove of the right-sided humeri was 64.996±11.611mm and the left humeri were 64.074±13.115mm. It is expected that this osteometric study of bicipital groove among the Bangladeshi population will be very helpful for clinical anatomists, orthopaedic surgeons, anthropologists and radiologists.
Asunto(s)
Cadáver , Húmero , Humanos , Bangladesh , Estudios Transversales , Húmero/anatomía & histología , Adulto , Masculino , FemeninoRESUMEN
The family Bovidae [Mammalia: Artiodactyla] is speciose and has extant representatives on every continent, forming key components of mammal communities. For these reasons, bovids are ideal candidates for studies of ecomorphology. In particular, the morphology of the bovid humerus has been identified as highly related to functional variables such as body mass and habitat. This study investigates the functional morphology of the bovid distal humerus in isolation due to its increased likelihood of preservation in the fossil record, and the resulting opportunity for a better understanding of the ecomorphology of extinct bovids. A landmark scheme of 30 landmarks was used to capture the 3D distal humerus morphology in 111 extant bovid specimens. We find that the distal humerus has identifiable morphologies associated with body mass, habitat preference and tribe affiliation and that some characteristics are shared between high body mass bovids and those living on hard, flat terrain which is likely due to the high stress on the bone in both cases. We directly apply our findings regarding extant bovids to the extinct alcelaphine bovid, Rusingoryx atopocranion from the mid to late Pleistocene (>33-45 ka) Lake Victoria region of Kenya. This species is known for some peculiar morphologies including a domed cranium with hollow nasal crests, and having small hooves for a bovid of its size. Another interesting aspect of Rusingoryx's skeletal morphology which has not been addressed is an unusual protrusion on the lateral epicondyle of the distal humerus. Despite considerable individual variation in the Rusingoryx specimens, we find evidence to support its historical assignment to the tribe Alcelaphini, and that it likely preferred open grassland habitats, which is consistent with independent reconstructions of the palaeoenvironment. We also provide the most accurate body mass estimate for Rusingoryx to date, based on distal humerus centroid size. Overall, we are able to conclude that the distal humerus in extant bovids is highly informative regarding body mass, habitat preference and tribe, and that this can be applied directly to a fossil taxon with promising results.
Asunto(s)
Fósiles , Húmero , Animales , Húmero/anatomía & histología , Fósiles/anatomía & histología , Imagenología Tridimensional , Rumiantes/anatomía & histologíaRESUMEN
AIMS: This study aimed to investigate age- and menopause-related differences in bone mineral density (BMD), bone structure and estimated bone strength at surgical neck of humerus in Chinese female sample. METHODS: We conducted a cross-sectional cohort study of 171 Chinese women. Bone mass, indices of geometric properties and estimated mechanical strength of the surgical neck were evaluated by quantitative computed tomography (QCT). Comparisons were performed across menstrual status categories. Age-related changes in QCT-derived bone parameters were calculated. RESULTS: The age-related difference of BMD and cortical thickness was 40.25 % and 32.86 % between the age of 20 and 86 years. Progressive periosteal and endosteal expansion was associated linearly with age. Estimated mechanical strength indexes showed significant quadratic associations with age, with their peak occurred at the age of 46-55 years. The quartile of women with the greatest medullary diameter also had the lowest valve of BMD and cortical thickness and the greatest in skeletal width. Compared to premenopausal individuals, perimenopausal women were distinguished by lower cortical thickness (18.63 %) and BMD (20.05 %). The continued decrease in cortical thickness and BMD was noted after menopause. The medullary and periosteal diameter increased by 17.98 % and 9.34 % respectively in perimenopausal period, but not after menopause. The accelerated loss of the maximum and polar section modulus was observed in late postmenopausal women. CONCLUSIONS: The increase in bone size only occurred during the menopause transition. Obvious loss of resistance to bending was in late postmenopausal period.
Asunto(s)
Envejecimiento , Densidad Ósea , Húmero , Tomografía Computarizada por Rayos X , Humanos , Femenino , Densidad Ósea/fisiología , Persona de Mediana Edad , Adulto , Estudios Transversales , Anciano , Húmero/anatomía & histología , Húmero/diagnóstico por imagen , Envejecimiento/fisiología , China , Anciano de 80 o más Años , Adulto Joven , Menopausia/fisiología , Pueblo Asiatico , Pueblos del Este de AsiaRESUMEN
OBJECTIVES: Adult upper limb asymmetry is used to reconstruct behavior. However, the developmental trajectory of asymmetry in bone length, cross-sectional geometry (CSG), and joint dimensions is poorly understood. This study examines the development trajectory of humeral asymmetry and if asymmetry in bone length, joint size, and CSG develop in concert. MATERIALS AND METHODS: Linear measurements of bone length and metaphyseal/epiphyseal breadth, bending rigidity (Imax and Imin), and cross-sectional shape (Imax/Imin) at 30%, 50%, and 70% of bone length were acquired from 3D models of humeri from four skeletal samples of prehistoric hunter-gatherer populations (n = 82). Dental age cohorts were used to assess ontogenetic trends. Percent absolute (%AA) and directional (%DA) asymmetry were calculated for paired measures. Percentage of matching direction of asymmetry across variables and correlation analysis tested relationships between variables. RESULTS: Within the total pooled sample, Imax shows the highest %AA and %DA, followed by shape and linear dimensions. Asymmetry is lowest in neonates and increases with age, particularly %DA of Imax in mid-proximal sections. Correlations among variables are low to moderate and strongest between Imax measures. Matching direction of asymmetry between variables is low and generally increases with age. DISCUSSION: Higher correlations with age in CSG likely indicate greater responsiveness to mechanical loading. Low correlations in magnitude of asymmetry and side dominance suggest independence in the development of asymmetry between maximum rigidity, shape, and linear measures. Differences in how asymmetric loading affects the ontogeny of linear and CSG variables may account for the heterogeneous development of asymmetry.
Asunto(s)
Húmero , Humanos , Húmero/anatomía & histología , Húmero/crecimiento & desarrollo , Femenino , Masculino , Niño , Adulto , Adolescente , Adulto Joven , Preescolar , Lactante , Antropología FísicaRESUMEN
OBJECTIVES: This study tests if femoral and humeral cross-sectional geometry (CSG) and cross-sectional properties (CSPs) in an ontogenetic series of wild-caught chimpanzees (Pan troglodytes ssp.) reflect locomotor behavior during development. The goal is to clarify the relationship between limb bone structure and locomotor behavior during ontogeny in Pan. MATERIALS AND METHODS: The latex cast method was used to reconstruct cross sections at the midshaft femur and mid-distal humerus. Second moments of area (SMAs) (Ix, Iy, Imax, Imin), which are proportional to bending rigidity about a specified axis, and the polar SMA (J), which is proportional to average bending rigidity, were calculated at section locations. Cross-sectional shape (CSS) was assessed from Ix/Iy and Imax/Imin ratios. Juvenile and adult subsamples were compared. RESULTS: Juveniles and adults have significantly greater femoral J compared to humeral J. Mean interlimb proportions of J are not significantly different between the groups. There is an overall decreasing trend in diaphyseal circularity between the juvenile phase of development and adulthood, although significant differences are only found in the humerus. DISCUSSION: Juvenile chimpanzee locomotion includes forelimb- and hindlimb-biased behaviors. Juveniles and adults preferentially load their hindlimbs relative to their forelimbs. This may indicate similar locomotor behavior, although other explanations including a diversity of hindlimb-biased locomotor behaviors in juveniles cannot be ruled out. Different ontogenetic trends in forelimb and hindlimb CSS are consistent with limb bone CSG reflecting functional adaptation, albeit the complex nature of bone functional adaptation requires cautious interpretations of skeletal functional morphology from biomechanical analyses.
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Diáfisis , Fémur , Húmero , Pan troglodytes , Animales , Pan troglodytes/crecimiento & desarrollo , Pan troglodytes/anatomía & histología , Húmero/anatomía & histología , Húmero/crecimiento & desarrollo , Húmero/fisiología , Diáfisis/anatomía & histología , Diáfisis/crecimiento & desarrollo , Diáfisis/fisiología , Fémur/anatomía & histología , Fémur/crecimiento & desarrollo , Fémur/fisiología , Femenino , Masculino , Locomoción/fisiologíaRESUMEN
SUMMARY: The updating of anatomical terms is essential to facilitate teaching and learning as well as international communication through publications and presentations at scientific events. In the posterior wall of the axilla, the teres major, teres minor and triceps brachii muscles form three spaces through which neurovascular structures of clinical significance run. The current study seeks to define and propose terms for these spaces which have been omitted by Terminologia Anatomica. The definition of the Latin term 'Spatium' was investigated using A Latin Dicionary, while the term 'Espacio' was analyzed using Diccionario panhispánico de términos médicos (Real Academia Nacional de Medicina de España, 2023), as well as the lexemes of the words 'scapula' and 'humerus', for which the Diccionario Médico-Biológico, Histórico y Etimológico de la Universidad de Salamanca was consulted. The presence of the term 'Spatium' in the Terminologia Anatomica was also investigated. Finally, 10 anatomy textbooks in Spanish were reviewed to identify the terms used for these spaces. In reviewing the latest edition of Terminologia Anatomica, it was found that the term 'Spatium' appears 25 times in different chapters and it was evident that no terms for scapulohumeral spaces appear in the chapters on upper limb structures. Moreover, in 100 % of the anatomy textbooks reviewed, at least one term is used to describe the scapulohumeral spaces. We believe that the proposed terms: 'Spatium humerotricipitale', 'Spatium scapulotricipitale' and 'Spatium teretricipitale' more accurately describe both the location and their association with the bone/muscle structures that form them. We therefore suggest that these terms be revised for inclusion in future editions of Terminologia Anatomica.
La actualización de términos anatómicos es esencial para facilitar la enseñanza-aprendizaje y comunicación internacional a través de publicaciones y presentaciones en eventos científicos. En la pared posterior de la axila, los músculos redondo mayor, redondo menor y tríceps braquial, forman tres espacios por donde discurren estructuras neurovasculares relevantes en la clínica. El estudio tuvo como objetivo definir y proponer términos para estos espacios omitidos por Terminologia Anatomica. En el diccionario A Latin Dictionary se investigó la definición en latín del término 'Spatium' y 'Espacio' en el Diccionario panhispánico de términos médicos (Real Academia Nacional de Medicina de España, 2023), además de los lexemas de las palabras 'escápula' y 'húmero' en el Diccionario Médico-Biológico, Histórico y Etimológico de la Universidad de Salamanca. También se investigó la presencia del término 'Spatium' en la Terminologia Anatomica. Por último, se revisaron 10 libros-textos de anatomía en español para identificar los términos utilizados para estos espacios y su relevancia clínica. Al revisar la última edición de Terminologia Anatomica, se observó que el término 'Spatium' aparece 25 veces en distintos capítulos y se evidenció que no aparecen términos para los espacios escapulohumerales en los capítulos de miembro superior. Además, en el 100 % de los libros-textos de anatomía revisados, se utiliza al menos un término para describir a los espacios escapulohumerales. Consideramos que los términos propuestos: 'Spatium humerotricipitale', 'Spatium scapulotricipitale' y 'Spatium teretricipitale' aluden con mayor precisión a la ubicación, ya que relaciona a las estructuras óseas y/ o musculares que lo forman. Por lo que sugerimos que estos términos sean revisados para incluirlos en futuras ediciones de Terminologia Anatomica.
Asunto(s)
Humanos , Escápula/anatomía & histología , Húmero/anatomía & histología , Terminología como AsuntoRESUMEN
OBJECTIVES: Estimation of body mass from skeletal metrics can reveal important insights into the paleobiology of archeological or fossil remains. The standard approach constructs predictive equations from postcrania, but studies have questioned the reliability of traditional measures. Here, we examine several skeletal features to assess their accuracy in predicting body mass. MATERIALS AND METHODS: Antemortem mass measurements were compared with common skeletal dimensions from the same animals postmortem, using 115 rhesus macaques (male: n = 43; female: n = 72). Individuals were divided into training (n = 58) and test samples (n = 57) to build and assess Ordinary Least Squares or multivariate regressions by residual sum of squares (RSS) and AIC weights. A leave-one-out approach was implemented to formulate the best fit multivariate models, which were compared against a univariate and a previously published catarrhine body-mass estimation model. RESULTS: Femur circumference represented the best univariate model. The best model overall was composed of four variables (femur, tibia and fibula circumference and humerus length). By RSS and AICw, models built from rhesus macaque data (RSS = 26.91, AIC = -20.66) better predicted body mass than did the catarrhine model (RSS = 65.47, AIC = 20.24). CONCLUSION: Body mass in rhesus macaques is best predicted by a 4-variable equation composed of humerus length and hind limb midshaft circumferences. Comparison of models built from the macaque versus the catarrhine data highlight the importance of taxonomic specificity in predicting body mass. This paper provides a valuable dataset of combined somatic and skeletal data in a primate, which can be used to build body mass equations for fragmentary fossil evidence.
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Macaca mulatta , Animales , Macaca mulatta/anatomía & histología , Femenino , Masculino , Antropología Física/métodos , Peso Corporal , Huesos/anatomía & histología , Húmero/anatomía & histologíaRESUMEN
The modular organization of tetrapod paired limbs and girdles, influenced by the expression of Hox genes is one of the primary driving forces of the evolution of animal locomotion. The increased morphological diversification of the paired limbs is correlated with reduced between-limb covariation, while correlation within the elements is usually higher than between the elements. The tailed amphibians, such as Lissotriton newts, have a biphasic lifestyle with aquatic and terrestrial environments imposing different constraints on limb skeleton. By employing the methods of computerized microtomography and 3D geometric morphometrics, we explored the pattern of morphological variation, disparity, modularity and morphological integration in the proximal parts of the anterior limbs of six species of Eurasian small bodied newts. Although the species significantly differ in limb shape, there is a great overlap in morphology of scapula and humerus, and there are no differences in morphological disparity. For the scapula, the shape differences related to the duration of the aquatic period are in length, depth and curvature. The shape of the humerus is not affected by the length of aquatic period, and shape differences between the species are related to robustness of the body. The length of aquatic period has statistically supported phylogenetic signal. The scapula and humerus are structures of varying modularity. For the humerus, the strongest support on the phylogenetic level was for the capitulum/shaft hypothesis, which can also be interpreted as functional modularity. For the scapula, the greatest support was for the antero-posterior hypothesis of modularity in case of Lissotriton vulgaris, which can be explained by different functional roles and muscle insertion patterns, while there was no phylogenetic modularity. The modularity patterns seem to correspond with the general tetrapod pattern, with modularity being more pronounced in the distal structure. The future research should include more salamandrid taxa with different habitat preferences and both adult and larval stages, in order to explore how size, phylogeny and ecology affect the morphology and covariation patterns of limbs.
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Húmero , Salamandridae , Escápula , Animales , Escápula/anatomía & histología , Salamandridae/anatomía & histología , Salamandridae/fisiología , Húmero/anatomía & histología , Evolución Biológica , Filogenia , Microtomografía por Rayos XRESUMEN
There is a need to fully understand intra-skeletal variability within different populations to develop and improve age-at-death estimation methods. This study evaluates age-related histomorphometric changes in three different bones intra-individually in a modern Australian sample. Four female and 13 male elderly Australian adult donors (67-93 years) were examined for osteon population density (OPD), osteon area (On.Ar), and Haversian canal area (H.Ar) of secondary osteons to compare between femora, ribs, and humeri and assess against age. In the pooled sex sample, no statistically significant correlations were observed between age and each histological variable. In the males, OPD of the femur increased significantly with age, as did porosity in the rib. In the male humeri, OPD increased moderately with age, while H.Ar was decreased moderately with age. Intra-bone comparisons showed that males had significantly higher osteon counts in their ribs compared to their femora, while their ribs showed statistically significantly less porosity than their humeri. When bone size was accounted for, by adjusting the femur and humerus histology data by robusticity indices, histology values were found to be similar between bones within the same individual. This is despite the upper and lower limbs receiving different ranges and types of biomechanical load. Our findings demonstrate that bone size influences histomorphometry, and this could confound age-at-death estimations that have not been adjusted for robusticity. Future studies would benefit from examining bone histomorphometry within a larger sample size and incorporating bone robusticity measures into histology analyses.
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Fémur , Osteón , Costillas , Humanos , Masculino , Anciano , Femenino , Anciano de 80 o más Años , Australia , Osteón/anatomía & histología , Fémur/anatomía & histología , Costillas/anatomía & histología , Envejecimiento/fisiología , Húmero/anatomía & histologíaRESUMEN
PURPOSE: Several descriptions of the anatomy of the pectoralis major (PM) have been published. However, the precise description of its distal humeral insertion, which is involved in traumatic tears, remains controversial. The distal tendon is classically described as being made of two layers, one anterior (ALPM) and one posterior (PLPM), which regroup at their distal edge. The clavicular head (CH) participates in the ALPM according to most authors. However, others describe a more superficial termination in a close relationship with the deltoid humeral insertion. The objective of this anatomical work is to precisely describe the anatomy of the CH and its relationship with the rest of the distal PM tendon and the distal deltoid tendon. MATERIALS: Twenty-three fresh cadaveric specimens were dissected (41 shoulders). The entire PM as well as the deltoid were exposed. Several measurements were collected to establish the relationships between the distal tendon of the CH and the PM, the deltoid and the bony landmarks. RESULTS: In all cases, the CH muscular portion sits on the ALPM but does not participate in the connective structure of the PM distal tendon. The inferolateral part of its distal end gives a thin tendinous portion that inserts lower on the humerus in conjunction with the distal tendon of the deltoid. In 24.4%, this tendon was more difficult to isolate but was always observed. CONCLUSIONS: The distal tendon of the PM only comes from the muscle fibres of its sternal head. The CH fibres do not contribute to this tendon but appear to terminate in a separate tendon fusing with the humeral insertion of the deltoid: the deltopectoral tendon. This could explain the different patterns of tears observed in clinical practice.
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Músculos Pectorales , Tendones , Humanos , Hombro , Clavícula , Húmero/anatomía & histología , CadáverRESUMEN
Background: Range of motion in the forelimb of the Upper Cretaceous theropod dinosaur Mononykus olecranus, a member of the family Alvarezsauridae, has previously been investigated. However, the method used to investigate range of motion at the shoulder in M. olecranus did not follow the standardized procedure used in subsequent studies. The latter procedure yields more reliable results, and its standardization provides that its results are directly comparable to the results of similar studies in other species. I therefore reinvestigated the range of motion at the shoulder in M. olecranus, using the latter procedure. Methods: Casts of the left scapula and coracoid of M. olecranus were posed on a horizontal surface, supported from beneath with modeling clay, with the medial surface of the scapula facing toward the horizontal surface. A cast of the left humerus was posed at the limits of motion through the transverse and parasagittal planes. Photos of the poses in orthal views were superimposed and used to measure range of motion, which was measured as the angle between lines drawn down the long axis of the humerus in each position. Results: Through the transverse plane, the humerus of M. olecranus could be elevated to a subhorizontal position and depressed to a subvertical position. It could move through the parasagittal plane from a subvertical position at full protraction to a position above the horizontal at full retraction. These results correct the previous mischaracterization of shoulder motion in M. olecranus as restricted to a small arc with the arms held in a permanent sprawl. The range of humeral motion in M. olecranus is much greater than that found by the previous method and allowed the animal to tuck its arms in at the sides, in addition to allowing them to sprawl so as to orient the palm downward. The wide range of humeral motion allowed M. olecranus to forage for insects by employing hook-and-pull digging at surfaces with a wider range of orientations than the previous study showed to be possible.
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Dinosaurios , Articulación del Hombro , Animales , Hombro , Articulación del Hombro/anatomía & histología , Escápula , Húmero/anatomía & histologíaRESUMEN
The fossil colobine genus Mesopithecus is the oldest European monkey, ranging from the Late Miocene to the earliest Pleistocene. It is one of the most successful genera of Old World monkeys since the late Neogene. Its ecology, as an indicator of Late Miocene environments, is of particular interest. Several investigations have clarified the locomotor adaptations of the middle and late Turolian Balkan Mesopithecus pentelicus, but such studies are virtually absent for the earliest known taxon, the early Turolian Mesopithecus delsoni, due to the lack of fossil material. However, a large collection of postcranial material of M. delsoni from the Bulgarian Early Turolian locality of Hadjidimovo provides the first opportunity for such an analysis. The present study examines the functional morphology of the fossil humeri of M. delsoni from Hadjidimovo, Bulgaria, and of M. pentelicus from Bulgarian and Greek fossil localities. We provide detailed comparative qualitative descriptions and use univariate and multivariate quantitative analyses of one angular and 12 linear measurements in comparison with 149 extant Cercopithecidae, representing 14 genera and 34 species. Our analyses demonstrate that the humeral elements from Hadjidimovo show important morphological differences from those of M. pentelicus from Pikermi, Kalimantsi, and Gorna Sushitsa, suggesting strong terrestrial tendencies for M. delsoni. This finding, when considered together with the paleobiologial inference of semiterrestriality for the early cercopithecoid Victoriapithecidae, might indicate that the first colobines (still unknown) were also semiterrestrial. Finally, the morphological features related to terrestriality in M. delsoni, which differ from those of the later M. pentelicus, provide additional data in support of the idea that the older taxon represents a separate species.
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Colobinae , Húmero , Bulgaria , Colobinae/anatomía & histología , Húmero/anatomía & histología , Masculino , Femenino , Animales , Evolución BiológicaRESUMEN
The middle Pliocene site of Woranso-Mille in the Afar Region of Ethiopia has yielded numerous significant early hominin fossils representing multiple, coexisting taxa. Here we report on another significant discovery, the oldest partial skeleton of the papionin, Theropithecus. The specimen was recovered from the Aralee Issie collection area over multiple field seasons from 2004 through 2019. The specimen was unearthed in situ from the fluvial facies of the Mesgid Dora Tuff dated to 3.66-3.57 Ma. The partial skeleton, ARI-VP-1/26, is that of a subadult male lacking a skull. In the absence of unambiguously associated craniodental remains, the male status of the specimen was established from the dimensions of the long bones in comparison to those of other Theropithecus from Woranso-Mille. ARI-VP-1/26 is noteworthy because it preserves partial hand and foot skeletons, including a complete set of metacarpals from the left side. The theropith status of ARI-VP-1/26 was established based on the detailed anatomy of the postcranial skeleton, especially the proximal and distal humerus, proximal radius, and proximal femur. The morphology of the postcranium of ARI-VP-1/26 is consistent with that of recognized Theropithecus from Woranso-Mille and, specifically, with specimens recognized as Theropithecus oswaldi cf. darti from other sites. The ratio of the lengths of the first metacarpal to metacarpals 2-5 in ARI-VP-1/26 is intermediate between that seen in extant Papio and Theropithecus. In Theropithecus gelada and Theropithecus brumpti, the pairing of pollical and indical metacarpals of near equal length contributes to the species' high opposability index and is associated with a 'manual grazing' feeding habit. Cercopithecids constitute 43% of the identified vertebrates at Aralee Issie, and T. oswaldi cf. darti is the most common mammalian species. The monkeys of Aralee Issie lived in an open shrubland habitat, but the specific reasons for their high prevalence at the site are unclear.
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Theropithecus , Animales , Masculino , Theropithecus/anatomía & histología , Cráneo/anatomía & histología , Fósiles , Ecosistema , Húmero/anatomía & histología , MamíferosRESUMEN
Skeletal pneumaticity is a key feature of extant avian structure and biology, which first evolved among the non-flying archosaurian ancestors of birds. The widespread presence of air-filled bones across the postcranial skeleton is unique to birds among living vertebrates, but the true extent of skeletal pneumaticity has never been quantitatively investigated-hindering fundamental insights into the evolution of this key avian feature. Here, we use microCT scans of fresh, frozen birds to directly quantify the fraction of humerus volume occupied by air across a phylogenetically diverse taxon sample to test longstanding hypotheses regarding the evolution and function of avian skeletal pneumatization. Among other insights, we document weak positive allometry of internal air volume with humeral size among pneumatized humeri and provide strong support that humeral size, body mass, aquatic diving, and the presence or absence of pneumaticity all have independent effects on cortical bone thickness. Our quantitative evaluation of humeral pneumaticity across extant avian phylogeny sheds new light on the evolution and ontogenetic progression of an important aspect of avian skeletal architecture, and suggests that the last common ancestor of crown birds possessed a highly pneumatized humerus.