The tubercle effect is a phenomenon where tubercles or large'bumps' on the leading edge of an airfoil can improve its aerodynamics. The effect, while discovered, was analyzed extensively by Frank E. Fish et al in the early 2000 onwards; the tubercle effect works by channeling flow over the airfoil into more narrow streams, creating higher velocities. Another side effect of these channels is the reduction of flow moving over the wingtip and resulting in less parasitic drag due to wingtip vortices. Using computational modeling, it was determined that the presence of tubercles produces a delay in the angle of attack until stall, thereby increasing maximum lift and decreasing drag. Fish first discovered this effect; these whales are the only known organisms. It is believed that this effect allows them to be much more maneuverable in the water, allowing for easier capture of prey; the tubercles on their fins allow them to do aquatic maneuvers to catch their prey. The tiny hooklets on the fore edge of an owl's wing have a similar effect that contributes to its aerodynamic maneuverability and stealth.
The Science Behind the Effect The tubercle effect is a phenomenon in which tubercles, or large raised bumps on the leading edge of a wing, blade, or sail increase its aerodynamic or hydrodynamic performance. Research on this topic was inspired by the work of marine biologists on the behavior of humpback whales. Despite their large size, these whales are able to perform rolls and loops underwater. Research on humpback whales indicated that the presence of these tubercles on the leading edge of whale fins reduced stall and increased lift, while reducing noise in the post-stall regime. Researchers were motivated by these positive results to apply these concepts to aircraft wings as well as industrial and wind turbines. Early research on this topic was performed by Watts & Fish followed by further experiments both in water and wind tunnels. Watts & Fish determined that the presence of tubercles on the leading edge of airfoil increased lift by 4.8%. Further numerical computations confirmed this result, indicated that the presence of tubercles can decrease the effects of drag by 40%.
Leading-edge tubercles have been found to reduce the point of maximum lift and increase the region of post-stall lift. In the post-stall regime, foils with tubercles experienced a gradual loss of lift as opposed to foils without tubercles, which experienced a sudden loss of lift. An example of a wing without protuberances compared to a wing with protuberances is shown; the geometry of tubercles must be considered, as the amplitude and wavelength of tubercles have an effect on flow control. Tubercles can be thought of as small delta wings with a curved apex, since they create a vortex on the upper edge of the tubercle; these vortical structures impose a downward deflection of the airflow over the crests of tubercles. This downward deflection delays stall on the airfoil. On the contrary, in the troughs of these structures, there is a net upward deflection of airflow. Localized upwash is associated with higher angles of attack, which relates to increased lift, as the flow separation occurs in the troughs and stays there.
The vortex created by the tubercle delays flow separation toward the trailing edge of the wing, thus reducing the effects of drag. However, in water, due to the crest/trough structure, cavitation is possible, is undesirable. Cavitation occurs in areas of high flow velocity and low pressure, such as the trough of a tubercled structure. In water, air bubbles or pockets form on the upper side of the tubercle; these bubbles reduce lift and increase drag, while increasing noise in the flow when the bubbles collapse. However, tubercles can be modified to manipulate the location of cavitation; the effect of amplitude of tubercles has a more significant impact on post-stall performance than wavelength. Higher amplitude of tubercles has been linked to more gradual stall and higher post-stall lift, as well as lower pre-stall lift slope; the wavelength and amplitude can both be optimized to increase the post-stall performance. Experiments on the effects of leading-edge tubercles have focused on rigid bodies, more research is needed in order to apply the knowledge of the tubercle effect to industrial, aircraft, or energy applications.
Biological Occurrences of Tubercles Tubercles are a material phenomenon that occurs in multiple organisms. These organisms include the humpback whale, hammerhead sharks and chondrichthyans, an extinct aquatic organism. One organism that tubercles are notable in is the humpback whale; the tubercles on humpback whales are located on the leading edge of the flippers. The tubercles allow the large whales to execute tight turns underwater and swim efficiently; the tubercles on the flippers help to maintain lift, preventing stall, decreasing the drag coefficient during turning maneuvers. Tubercles on the humpback whale are considered passive flow control. Tubercles develop in the fetus of the humpback whale. 9-11 tubercles are present on each flipper and decrease in size as they near the tip of the flipper. The largest tubercles are the forth tubercles from the shoulder of the whale; this anatomical structure is common among large fish species predatory species on their pectoral fins. Modern Applications in Industry Leading edge tubercles are up and coming in the manufacturing area.
Wind turbine performances rely on blade aerodynamics where similar flow characteristics are observed modern turbines have twisted blades to account for the angle of attack at specific design conditions. However, in practical applicati
Skeletal muscle is one of three major muscle types, the others being cardiac muscle and smooth muscle. It is a form of striated muscle tissue, under the voluntary control of the somatic nervous system. Most skeletal muscles are attached to bones by bundles of collagen fibers known as tendons. A skeletal muscle refers to multiple bundles of cells joined together called muscle fibers; the fibers and muscles are surrounded by connective tissue layers called fasciae. Muscle fibers, or muscle cells, are formed from the fusion of developmental myoblasts in a process known as myogenesis. Muscle fibers have more than one nucleus, they have multiple mitochondria to meet energy needs. Muscle fibers are in turn composed of myofibrils; the myofibrils are composed of actin and myosin filaments, repeated in units called sarcomeres, which are the basic functional units of the muscle fiber. The sarcomere is responsible for the striated appearance of skeletal muscle and forms the basic machinery necessary for muscle contraction.
Connective tissue is present in all muscles as fascia. Enclosing each muscle is a layer of connective tissue known as the epimysium. Muscle fibers are the individual contractile units within a muscle. A single muscle such as the biceps brachii contains many muscle fibers. Another group of cells, the myosatellite cells are found between the basement membrane and the sarcolemma of muscle fibers; these cells are quiescent but can be activated by exercise or pathology to provide additional myonuclei for muscle growth or repair. DevelopmentIndividual muscle fibers are formed during development from the fusion of several undifferentiated immature cells known as myoblasts into long, multi-nucleated cells. Differentiation into this state is completed before birth with the cells continuing to grow in size thereafter. MicroanatomySkeletal muscle exhibits a distinctive banding pattern when viewed under the microscope due to the arrangement of cytoskeletal elements in the cytoplasm of the muscle fibers; the principal cytoplasmic proteins are myosin and actin which are arranged in a repeating unit called a sarcomere.
The interaction of myosin and actin is responsible for muscle contraction. Every single organelle and macromolecule of a muscle fiber is arranged to ensure form meets function; the cell membrane is called the sarcolemma with the cytoplasm known as the sarcoplasm. In the sarcoplasm are the myofibrils; the myofibrils are long protein bundles about 1 micrometer in diameter each containing myofilaments. Pressed against the inside of the sarcolemma are the unusual flattened myonuclei. Between the myofibrils are the mitochondria. While the muscle fiber does not have smooth endoplasmic cisternae, it contains a sarcoplasmic reticulum; the sarcoplasmic reticulum surrounds the myofibrils and holds a reserve of the calcium ions needed to cause a muscle contraction. Periodically, it has dilated end sacs known as terminal cisternae; these cross the muscle fiber from one side to the other. In between two terminal cisternae is a tubular infolding called a transverse tubule. T tubules are the pathways for action potentials to signal the sarcoplasmic reticulum to release calcium, causing a muscle contraction.
Together, two terminal cisternae and a transverse tubule form a triad. Muscle architecture refers to the arrangement of muscle fibers relative to the axis of force generation of the muscle; this axis is a hypothetical line from the muscle's origin to insertion. For some longitudinal muscles, such as the biceps brachii, this is a simple concept. For others, such as the rectus femoris or deltoid muscle, it becomes more complicated. While the muscle fibers of a fascicle lie parallel to one another, the fascicles themselves can vary in their relationship to one another and to their tendons; the different fiber arrangements produce broad categories of skeletal muscle architectures including longitudinal, unipennate and multipennate. Because of these different architectures, the tension a muscle can create between its tendons varies by more than its size and fiber-type makeup. Longitudinal architectureThe fascicles of longitudinally arranged, parallel, or fusiform muscles run parallel to the axis of force generation, thus these muscles on a whole function to a single, large muscle fiber.
Variations exist, the different terms are used more specifically. For instance, fusiform refers to a longitudinal architecture with a widened muscle belly, while parallel may refer to a more ribbon-shaped longitudinal architecture. A less common example would be a circular muscle such as the orbicularis oculi, in which the fibers are longitudinally arranged, but create a circle from origin to insertion. Unipennate architectureThe fibers in unipennate muscles are all oriented at the same angle relative to the axis of force generation; this angle reduces the effective force of any individual fiber, as it is pulling off-axis. However, because of this angle, more fibers can be packed into the same muscle volume, increasing the Physiological cross-sectional area; this effect is known as fiber packing, and—in terms of force generation—it more than overcomes the efficiency loss of the off-axis orientation. The trade-off comes in the total excursion. Overall muscle shortening speed is reduced compared to fiber shortening speed, as is the total distance of shortening.
All of these effects scale with pennation angle.
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago, although the exact origin and timing of the evolution of dinosaurs is the subject of active research. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201 million years ago. Reverse genetic engineering and the fossil record both demonstrate that birds are modern feathered dinosaurs, having evolved from earlier theropods during the late Jurassic Period; as such, birds were the only dinosaur lineage to survive the Cretaceous–Paleogene extinction event 66 million years ago. Dinosaurs can therefore be divided into birds; this article deals with non-avian dinosaurs. Dinosaurs are a varied group of animals from taxonomic and ecological standpoints. Birds, at over 10,000 living species, are the most diverse group of vertebrates besides perciform fish. Using fossil evidence, paleontologists have identified over 500 distinct genera and more than 1,000 different species of non-avian dinosaurs.
Dinosaurs are represented on every continent by fossil remains. Through the first half of the 20th century, before birds were recognized to be dinosaurs, most of the scientific community believed dinosaurs to have been sluggish and cold-blooded. Most research conducted since the 1970s, has indicated that all dinosaurs were active animals with elevated metabolisms and numerous adaptations for social interaction; some were herbivorous, others carnivorous. Evidence suggests that egg-laying and nest-building are additional traits shared by all dinosaurs and non-avian alike. While dinosaurs were ancestrally bipedal, many extinct groups included quadrupedal species, some were able to shift between these stances. Elaborate display structures such as horns or crests are common to all dinosaur groups, some extinct groups developed skeletal modifications such as bony armor and spines. While the dinosaurs' modern-day surviving avian lineage are small due to the constraints of flight, many prehistoric dinosaurs were large-bodied—the largest sauropod dinosaurs are estimated to have reached lengths of 39.7 meters and heights of 18 meters and were the largest land animals of all time.
Still, the idea that non-avian dinosaurs were uniformly gigantic is a misconception based in part on preservation bias, as large, sturdy bones are more to last until they are fossilized. Many dinosaurs were quite small: Xixianykus, for example, was only about 50 cm long. Since the first dinosaur fossils were recognized in the early 19th century, mounted fossil dinosaur skeletons have been major attractions at museums around the world, dinosaurs have become an enduring part of world culture; the large sizes of some dinosaur groups, as well as their monstrous and fantastic nature, have ensured dinosaurs' regular appearance in best-selling books and films, such as Jurassic Park. Persistent public enthusiasm for the animals has resulted in significant funding for dinosaur science, new discoveries are covered by the media; the taxon'Dinosauria' was formally named in 1841 by paleontologist Sir Richard Owen, who used it to refer to the "distinct tribe or sub-order of Saurian Reptiles" that were being recognized in England and around the world.
The term is derived from Ancient Greek δεινός, meaning'terrible, potent or fearfully great', σαῦρος, meaning'lizard or reptile'. Though the taxonomic name has been interpreted as a reference to dinosaurs' teeth and other fearsome characteristics, Owen intended it to evoke their size and majesty. Other prehistoric animals, including pterosaurs, ichthyosaurs and Dimetrodon, while popularly conceived of as dinosaurs, are not taxonomically classified as dinosaurs. Pterosaurs are distantly related to dinosaurs; the other groups mentioned are, like dinosaurs and pterosaurs, members of Sauropsida, except Dimetrodon. Under phylogenetic nomenclature, dinosaurs are defined as the group consisting of the most recent common ancestor of Triceratops and Neornithes, all its descendants, it has been suggested that Dinosauria be defined with respect to the MRCA of Megalosaurus and Iguanodon, because these were two of the three genera cited by Richard Owen when he recognized the Dinosauria. Both definitions result in the same set of animals being defined as dinosaurs: "Dinosauria = Ornithischia + Saurischia", encompassing ankylosaurians, ceratopsians, ornithopods and sauropodomorphs.
Birds are now recognized as being the sole surviving lineage of theropod dinosaurs. In traditional taxonomy, birds were considered a separate class that had evolved from dinosaurs, a distinct superorder. However, a majority of contemporary paleontologists concerned with dinosaurs reject the traditional style of classification in favor of phylogenetic taxonomy. Birds are thus considered to be dinosaurs and dinosaurs are, not extinct. Birds are classified as belonging to the subgroup M
Hadrosaurids, or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts; the family, which includes ornithopods such as Edmontosaurus and Parasaurolophus, was a common group of herbivores during the Late Cretaceous Period in what is now Asia, Antarctica, South America, North America. Hadrosaurids are descendants of the Upper Jurassic/Lower Cretaceous iguanodontian dinosaurs and had a similar body layout. Like other ornithischians, hadrosaurids had a predentary bone and a pubic bone, positioned backwards in the pelvis. Hadrosauridae is divided into two principal subfamilies: the lambeosaurines, which had hollow cranial crests or tubes. Saurolophines tended to be bulkier than lambeosaurines. Lambeosaurines included the aralosaurins, tsintaosaurins and parasaurolophins, while saurolophines included the brachylophosaurins, kritosaurins and edmontosaurins. Hadrosaurids were facultative bipeds, with the young of some species walking on two legs and the adults walking on four.
Their jaws were evolved for grinding plants, with multiple rows of teeth replacing each other as the teeth wore down. Hadrosaurids were the first dinosaur family to be identified in North America - the first traces being found in 1855-1856 with the discovery of fossil teeth. Joseph Leidy examined the teeth, erected the genera Trachodon and Thespesius. One species was named Trachodon mirabilis. Trachodon included all sorts of cerapod dinosaurs, including ceratopsids, is now considered an invalid genus. In 1858, the teeth were associated with Leidy's eponymous Hadrosaurus foulkii, named after the fossil hobbyist William Parker Foulke. More and more teeth were found, resulting in more genera. A well preserved complete hadrosaurid specimen, AMNH 5060, was recovered in 1908 by the fossil collector Charles Hazelius Sternberg and his three sons, in Converse County, Wyoming. Analyzed by Henry Osborn in 1912, it has come to be known as the "Trachodon mummy"; this specimen's skin was completely preserved in the form of impressions.
The family Hadrosauridae was first used by Edward Drinker Cope in 1869. Since its creation, a major division has been recognized in the group between the hollow-crested subfamily Lambeosaurinae and the subfamily Saurolophinae known as Hadrosaurinae. Both of these have been robustly support in all recent literature. Phylogenetic analysis has increased the resolution of hadrosaurid relationships leading to the widespread usage of tribes to describe the finer relationships within each group of hadrosaurids.. Lambeosaurines have been traditionally split into Parasaurolophini and Lambeosaurini; these terms entered the formal literature in Evans and Reisz's 2007 redescription of Lambeosaurus magnicristatus. Lambeosaurini is defined as all taxa more related Lambeosaurus lambei than to Parasaurolophus walkeri, Parasaurolophini as all those taxa closer to P. walkeri than to L. lambei. In recent years Tsintaosaurini and Aralosaurini have emerged; the use of the term Hadrosaurinae was questioned in a comprehensive study of hadrosaurid relationships by Albert Prieto-Márquez in 2010.
Prieto-Márquez noted that, though the name Hadrosaurinae had been used for the clade of crestless hadrosaurids by nearly all previous studies, its type species, Hadrosaurus foulkii, has always been excluded from the clade that bears its name, in violation of the rules for naming animals set out by the ICZN. Prieto-Márquez defined Hadrosaurinae as just the lineage containing H. foulkii, used the name Saurolophinae instead for the traditional grouping. Hadrosauridae was first defined as a clade, by Forster, in a 1997 abstract, as "Lambeosaurinae plus Hadrosaurinae and their most recent common ancestor". In 1998, Paul Sereno defined the clade Hadrosauridae as the most inclusive possible group containing Saurolophus and Parasaurolophus emending the definition to include Hadrosaurus, the type genus of the family, which ICZN rules state must be included, despite its status as a nomen dubium. According to Horner et al. Sereno's definition would place a few other well-known hadrosaurs outside the family, which led them to define the family to include Telmatosaurus by default.
Prieto-Marquez reviewed the phylogeny of Hadrosauridae in 2010, including many taxa within the family. Below is a cladogram from al.. 2016. This cladogram is a recent modification of the original 2010 analysis, including more characters and taxa; the resulting cladistic tree of their analysis was resolved using Maximum-Parsimony. 61 hadrosauroid species were included, characterized for 273 morphological features: 189 for cranial features and 84 for postcranial features. When characters had multiple states that formed an evolutionary scheme, they were ordered to account for the evolution of one state into the next; the final tree was run through TNT version 1.0. The most recognizable aspect of hadrosaur anatomy is the flattened and laterally stretched rostral bones, which gives the distinct duck-bill look, some members of the hadrosaurs had massive crests on their heads for display. In some genera, including Edmontosaurus, the whole fron
Phyllidia varicosa is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Phyllidiidae. This species is distributed throughout the Indo-West Pacific Oceans including the central Pacific and the Red Sea; this is a large species growing to at least 115 mm. It can be distinguished by its numerous, tuberculate notal ridges; the ridge and bases of the tubercles are a blue-grey colour. The tubercles are capped in yellow; the foot sole has a black longitudinal foot stripe. The rhinophoral clavus possesses 27 to 30 lamellae. Juveniles of the sea cucumber, Pearsonothuria graeffei are brightly coloured and resemble Phyllidia varicosa, they are white and blue or black, with a few large, thorn-like projections. These bright colours warn predators of the toxicity of the nudibranch, this mimicry on the part of the sea cucumber species serves to protect it also; the adult sea cucumber has much duller colouration, but it is much larger than the sea slug and has its own toxic chemicals at this stage.
Erwin Koehler Phyllidia varicosa Lamarck, 1801. Philippine Sea Slugs, accessed 2016-11-15
Richard Swann Lull
Richard Swann Lull was an American paleontologist and Sterling Professor at Yale University, remembered now for championing a non-Darwinian view of evolution, whereby mutation could unlock presumed "genetic drives" that, over time, would lead populations to extreme phenotypes. Lull was born in Annapolis, the son of naval officer Edward Phelps Lull and Elizabeth Burton, daughter of General Henry Burton, he married Clara Coles Boggs and he has a daughter Dorothy. He majored in zoology at Rutgers College where he received both his undergraduate and master's degrees, he worked for the Division of Entomology of the United States Department of Agriculture, but in 1894 became an assistant professor of zoology at the State Agricultural College in Amherst, Massachusetts. Lull's interest in fossil footprints began at Amherst College, renowned for its collection of fossil footprints, led him to switch from entomology to paleontology. In 1899 Lull worked as a member of the American Museum of Natural History's expedition to Bone Cabin Quarry, helping to collect that museum's brontosaur skeleton.
In 1902 he again joined an American Museum team in Montana studied under Columbia University Prof. Henry Fairfield Osborn. In 1903 he received his Ph. D. from Columbia University, in 1906, after a brief time at Amherst, was named Assistant Professor of Vertebrate Paleontology in Yale College and Associate Curator of Vertebrate Paleontology at the Peabody Museum of Natural History. He stayed at Yale for the next 50 years. In 1933 Lull was awarded the Daniel Giraud Elliot Medal from the National Academy of Sciences. One famous example he used to support his non-Darwinian evolution theory concerned the enormous antlers of the Irish elk: he argued that these could not be the result of natural selection, instead reflected one of his "unlocked genetic drives" towards increasing antler size; the poor elk, coping in each generation with ever-bigger antlers were driven extinct. His evolutionary theory was a form of orthogenesis, his book Organic Evolution received positive reviews and was described as an "excellent summary of the theories and factors of evolution."
Fossils: What They Tell Us of Plants and Animals of the Past A Revision of the Ceratopsia or Horned Dinosaurs The Ways of Life Organic Evolution Fossil Footprints of the Jura-Trias of North America Yale History and Archives: Richard Swann Lull Works by or about Richard Swann Lull at Internet Archive Works by Richard Swann Lull at LibriVox
The human skeleton is the internal framework of the body. It is composed of around 270 bones at birth – this total decreases to around 206 bones by adulthood after some bones get fused together; the bone mass in the skeleton reaches maximum density around age 21. The human skeleton can be divided into the appendicular skeleton; the axial skeleton is formed by the vertebral column, the rib cage, the skull and other associated bones. The appendicular skeleton, attached to the axial skeleton, is formed by the shoulder girdle, the pelvic girdle and the bones of the upper and lower limbs; the human skeleton performs six major functions. The human skeleton is not as sexually dimorphic as that of many other primate species, but subtle differences between sexes in the morphology of the skull, long bones, pelvis exist. In general, female skeletal elements tend to be smaller and less robust than corresponding male elements within a given population; the human female pelvis is different from that of males in order to facilitate childbirth.
Unlike most primates, human males do not have penile bones. The axial skeleton is formed by the vertebral column, a part of the rib cage, the skull; the upright posture of humans is maintained by the axial skeleton, which transmits the weight from the head, the trunk, the upper extremities down to the lower extremities at the hip joints. The bones of the spine are supported by many ligaments; the erector spinae muscles are supporting and are useful for balance. The appendicular skeleton is formed by the pectoral girdles, the upper limbs, the pelvic girdle or pelvis, the lower limbs, their functions are to make locomotion possible and to protect the major organs of digestion and reproduction. The skeleton serves six major functions: support, protection, production of blood cells, storage of minerals and endocrine regulation; the skeleton provides the framework which maintains its shape. The pelvis, associated ligaments and muscles provide a floor for the pelvic structures. Without the rib cages, costal cartilages, intercostal muscles, the lungs would collapse.
The joints between bones allow movement, some allowing a wider range of movement than others, e.g. the ball and socket joint allows a greater range of movement than the pivot joint at the neck. Movement is powered by skeletal muscles, which are attached to the skeleton at various sites on bones. Muscles and joints provide the principal mechanics for movement, all coordinated by the nervous system, it is believed that the reduction of human bone density in prehistoric times reduced the agility and dexterity of human movement. Shifting from hunting to agriculture has caused human bone density to reduce significantly; the skeleton helps to protect our many vital internal organs from being damaged. The skull protects the brain; the rib cage and sternum protect the lungs and major blood vessels. The skeleton is the site of haematopoiesis, the development of blood cells that takes place in the bone marrow. In children, haematopoiesis occurs in the marrow of the long bones such as the femur and tibia.
In adults, it occurs in the pelvis, cranium and sternum. The bone matrix can store calcium and is involved in calcium metabolism, bone marrow can store iron in ferritin and is involved in iron metabolism. However, bones are not made of calcium, but a mixture of chondroitin sulfate and hydroxyapatite, the latter making up 70% of a bone. Hydroxyapatite is in turn composed of 39.8% of calcium, 41.4% of oxygen, 18.5% of phosphorus, 0.2% of hydrogen by mass. Chondroitin sulfate is a sugar made up of oxygen and carbon. Bone cells release a hormone called osteocalcin, which contributes to the regulation of blood sugar and fat deposition. Osteocalcin increases both the insulin secretion and sensitivity, in addition to boosting the number of insulin-producing cells and reducing stores of fat. Anatomical differences between human males and females are pronounced in some soft tissue areas, but tend to be limited in the skeleton; the human skeleton is not as sexually dimorphic as that of many other primate species, but subtle differences between sexes in the morphology of the skull, long bones, pelvis are exhibited across human populations.
In general, female skeletal elements tend to be smaller and less robust than corresponding male elements within a given population. It is not known to what extent those differences are genetic or environmental. A variety of gross morphological traits of the human skull demonstrate sexual dimorphism, such as the median nuchal line, mastoid processes, supraorbital margin, supraorbital ridge, the chin. Human inter-sex dental dimorphism centers on the canine teeth, but it is not nearly as pronounced as in the other great apes. Long bones are larger in males than in females within a given population. Muscle attachment sites on long bones are more robust in males than in females, reflecting a difference in overall muscle mass and development between sexes. Sexual dimorphism in the long bones is characterized by morphometric or gross morphological analyses; the human pelvis exhibits greater sexual dimorphism than other bones in the size and shape of the pelvic cavity, greater sciatic notches, the sub-pubic angle.
The Phenice method is us