1.
Common ostrich
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The ostrich or common ostrich is either one or two species of large flightless birds native to Africa, the only living member of the genus Struthio, which is in the ratite family. In 2014, the Somali ostrich was recognized as a distinct species, the common ostrich shares the order Struthioniformes with the kiwis, emus, rheas, and cassowaries. However, phylogenetic studies have shown that it is the group to all other members of Palaeognathae. It is distinctive in its appearance, with a neck and legs, and can run at up to about 70 km/h. The common ostrich is the largest living species of bird and lays the largest eggs of any living bird, the common ostrichs diet consists mainly of plant matter, though it also eats invertebrates. It lives in groups of 5 to 50 birds. When threatened, the ostrich will either hide itself by lying flat against the ground, if cornered, it can attack with a kick of its powerful legs. Mating patterns differ by region, but territorial males fight for a harem of two to seven females. The common ostrich is farmed around the world, particularly for its feathers and its skin is used for leather products and its meat is marketed commercially, with its leanness a common marketing point. Common ostriches usually weigh from 63 to 145 kilograms, or as much as two adult humans, ostriches of the East African race averaged 115 kg in males and 100 kg in females, while the nominate subspecies was found to average 111 kg in unsexed adults. Exceptional male ostriches can weigh up to 156.8 kg, at sexual maturity, male common ostriches can be from 2.1 to 2.8 m in height, while female common ostriches range from 1.7 to 2.0 m tall. New chicks are fawn in colour, with brown spots. During the first year of life, chicks grow at about 25 cm per month, at one year of age, common ostriches weigh approximately 45 kilograms. Their lifespan is up to 40–45 years, the feathers of adult males are mostly black, with white primaries and a white tail. However, the tail of one subspecies is buff, females and young males are greyish-brown and white. The head and neck of both male and female ostriches is nearly bare, with a layer of down. The skin of the neck and thighs is pinkish gray. The eyes are shaded from sunlight from above, However, the head and bill are relatively small for the birds huge size, with the bill measuring 12 to 14.3 cm
2.
Eadweard Muybridge
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Eadweard Muybridge was an English photographer important for his pioneering work in photographic studies of motion, and early work in motion-picture projection. He adopted the name Eadweard Muybridge, believing it to be the original Anglo-Saxon form of his name, at age 20, he emigrated to America, first to New York, as a bookseller, and then to San Francisco. He returned to England in 1861, and took up photography, learning the wet-plate collodion process. He went back to San Francisco in 1867, and in 1868 his large photographs of Yosemite Valley made him world-famous, in 1874 he shot and killed Major Harry Larkyns, his wifes lover, but was acquitted in a jury trial on the grounds of justifiable homicide. He travelled for more than a year in Central America on an expedition in 1875. He spent much of his later years giving lectures and demonstrations of his photography and early motion picture sequences, travelling back to England. He also edited and published compilations of his work, which greatly influenced visual artists and he returned to his native England permanently in 1894, and in 1904, the Kingston Museum, containing a collection of his equipment, was opened in his hometown. Edward James Muggeridge was born and raised in England, Muggeridge changed his name several times, starting with Muggridge. In 1855, in the United States, he used the surname Muygridge, after he returned from Britain to the United States in 1867, he used the surname Muybridge. In addition, he used the pseudonym Helios to sign many of his photographs and he also used this as the name of his studio and made it the middle name for his only son, Florado Helios Muybridge, born in 1874. While travelling on an expedition in the Spanish-speaking nations of Central America in 1875. After an 1882 trip to England, he changed the spelling of his first name to Eadweard and he used Eadweard Muybridge for the rest of his career, but his gravestone carries his name as Eadweard Maybridge. Muybridge was born in Kingston upon Thames, in the county of Surrey in England, on 9 April 1830 to John and Susanna Muggeridge, he had three brothers. His father was a grain and coal merchant, with spaces on the ground floor of their house adjacent to the River Thames at No.30 High Street. After his father died in 1843, his mother carried on the business and his cousin Norman Selfe who also grew up in Kingston upon Thames moved to Australia and, following a family tradition, became a renowned engineer. Edwards younger brother George born in 1833 is found living with his Uncle Samuel in 1851 after the death of his Father in 1843 which establishes the lineage of Edward James Muggeridge. He started a career as a agent for the London Printing and Publishing Company. At the time, the city was booming, with 40 bookstores, nearly 60 hotels, later in his life, he wrote about also having spent time in New Orleans and New York City during his early years in the United States
3.
Terrestrial locomotion
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Terrestrial locomotion has evolved as animals adapted from aquatic to terrestrial environments. Locomotion on land raises different problems than that in water, with reduced friction being replaced by the effects of gravity, important aspects of legged locomotion are posture, the number of legs, and the functional structure of the leg and foot. There are also many gaits, ways of moving the legs to locomote, such as walking, running, appendages can be used for movement in a number of ways. The posture, the way the body is supported by the legs, is an important aspect, there are three main ways in which vertebrates support themselves with their legs - sprawling, semi-erect, and fully erect. Some animals may use different postures in different circumstances, depending on the mechanical advantages. Interestingly, there is no difference in energetic cost between stances. The sprawling posture is the most primitive, and is the limb posture from which the others evolved. The upper limbs are held horizontally, while the lower limbs are vertical. The body may drag along the ground, as in salamanders, or may be substantially elevated and this posture is typically associated with trotting gaits, and the body flexes from side-to-side during movement to increase step length. All limbed reptiles and salamanders use this posture, as does the platypus, unusual examples can be found among amphibious fish, such as the mudskipper, which drag themselves across land on their sturdy fins. Among the invertebrates, most arthropods—which includes the most diverse group of animals, there is also anecdotal evidence that some octopus species can also drag themselves across land a short distance by hauling their body along by their tentacles - there may be video evidence of this. The semi-erect posture is more accurately interpreted as an extremely elevated sprawling posture and this mode of locomotion is typically found in large lizards such as monitor lizards and tegus. Mammals and birds typically have an erect posture, though each evolved it independently. In these groups the legs are placed beneath the body and this is often linked with the evolution of endothermy, as it avoids Carriers constraint and thus allows prolonged periods of activity. For example, the mesozoic prehistoric crocodilian Erpetosuchus is believed to have had an erect stance. The number of locomotory appendages varies much between animals, and sometimes the same animal may use different numbers of its legs in different circumstances, a number of species move and stand on two legs, that is, they are bipedal. The group that is exclusively bipedal is the birds, which have either an alternating or a hopping gait, there are also a number of bipedal mammals. Most of these move by hopping – including the macropods such as kangaroos, only a few mammals such as humans and the ground pangolin commonly show an alternating bipedal gait
4.
Motion (physics)
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In physics, motion is a change in position of an object over time. Motion is described in terms of displacement, distance, velocity, acceleration, time, motion of a body is observed by attaching a frame of reference to an observer and measuring the change in position of the body relative to that frame. If the position of a body is not changing with respect to a frame of reference. An objects motion cannot change unless it is acted upon by a force, momentum is a quantity which is used for measuring motion of an object. As there is no frame of reference, absolute motion cannot be determined. Thus, everything in the universe can be considered to be moving, more generally, motion is a concept that applies to objects, bodies, and matter particles, to radiation, radiation fields and radiation particles, and to space, its curvature and space-time. One can also speak of motion of shapes and boundaries, so, the term motion in general signifies a continuous change in the configuration of a physical system. For example, one can talk about motion of a wave or about motion of a quantum particle, in physics, motion is described through two sets of apparently contradictory laws of mechanics. Motions of all large scale and familiar objects in the universe are described by classical mechanics, whereas the motion of very small atomic and sub-atomic objects is described by quantum mechanics. It produces very accurate results within these domains, and is one of the oldest and largest in science, engineering, classical mechanics is fundamentally based on Newtons laws of motion. These laws describe the relationship between the acting on a body and the motion of that body. They were first compiled by Sir Isaac Newton in his work Philosophiæ Naturalis Principia Mathematica and his three laws are, A body either is at rest or moves with constant velocity, until and unless an outer force is applied to it. An object will travel in one direction only until an outer force changes its direction, whenever one body exerts a force F onto a second body, the second body exerts the force −F on the first body. F and −F are equal in magnitude and opposite in sense, so, the body which exerts F will go backwards. Newtons three laws of motion, along with his Newtons law of motion, which were the first to provide a mathematical model for understanding orbiting bodies in outer space. This explanation unified the motion of bodies and motion of objects on earth. Classical mechanics was later enhanced by Albert Einsteins special relativity. Motion of objects with a velocity, approaching the speed of light
5.
Limb (anatomy)
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A limb, or extremity, is a jointed, or prehensile, appendage of the human or other animal body. In the human body, the upper and lower limbs are called the arms. Most animals use limbs for locomotion, such as walking, running, some animals can use their front limbs to carry and manipulate objects. Some animals can also use hind limbs for manipulation, human legs and feet are specialized for two-legged locomotion – most other mammals walk and run on all four limbs. Human arms are weaker, but very mobile allowing us to reach at a range of distances and angles
6.
Animal
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Animals are multicellular, eukaryotic organisms of the kingdom Animalia. The animal kingdom emerged as a clade within Apoikozoa as the group to the choanoflagellates. Animals are motile, meaning they can move spontaneously and independently at some point in their lives and their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later in their lives. All animals are heterotrophs, they must ingest other organisms or their products for sustenance, most known animal phyla appeared in the fossil record as marine species during the Cambrian explosion, about 542 million years ago. Animals can be divided broadly into vertebrates and invertebrates, vertebrates have a backbone or spine, and amount to less than five percent of all described animal species. They include fish, amphibians, reptiles, birds and mammals, the remaining animals are the invertebrates, which lack a backbone. These include molluscs, arthropods, annelids, nematodes, flatworms, cnidarians, ctenophores, the study of animals is called zoology. The word animal comes from the Latin animalis, meaning having breath, the biological definition of the word refers to all members of the kingdom Animalia, encompassing creatures as diverse as sponges, jellyfish, insects, and humans. Aristotle divided the world between animals and plants, and this was followed by Carl Linnaeus, in the first hierarchical classification. In Linnaeuss original scheme, the animals were one of three kingdoms, divided into the classes of Vermes, Insecta, Pisces, Amphibia, Aves, and Mammalia. Since then the last four have all been subsumed into a single phylum, in 1874, Ernst Haeckel divided the animal kingdom into two subkingdoms, Metazoa and Protozoa. The protozoa were later moved to the kingdom Protista, leaving only the metazoa, thus Metazoa is now considered a synonym of Animalia. Animals have several characteristics that set apart from other living things. Animals are eukaryotic and multicellular, which separates them from bacteria and they are heterotrophic, generally digesting food in an internal chamber, which separates them from plants and algae. They are also distinguished from plants, algae, and fungi by lacking cell walls. All animals are motile, if only at life stages. In most animals, embryos pass through a stage, which is a characteristic exclusive to animals. With a few exceptions, most notably the sponges and Placozoa and these include muscles, which are able to contract and control locomotion, and nerve tissues, which send and process signals
7.
Machine
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A machine is a tool containing one or more parts that uses energy to perform an intended action. Machines are usually powered by chemical, thermal, or electrical means, historically, a power tool also required moving parts to classify as a machine. However, the advent of electronics has led to the development of power tools without moving parts that are considered machines, a simple machine is a device that simply transforms the direction or magnitude of a force, but a large number of more complex machines exist. Examples include vehicles, electronic systems, molecular machines, computers, television, the word machine derives from the Latin word machina, which in turn derives from the Greek. The word mechanical comes from the same Greek roots, however, the Ancient Greeks probably have borrowed the word mekhane from the ancient Hebrews. The ancient Greeks were familiar with the Hebrew Scriptures and language, a wider meaning of fabric, structure is found in classical Latin, but not in Greek usage. This meaning is found in late medieval French, and is adopted from the French into English in the mid-16th century, in the 17th century, the word could also mean a scheme or plot, a meaning now expressed by the derived machination. The modern meaning develops out of specialized application of the term to stage engines used in theater and to siege engines. Simple Machines are commonly reckoned to be Six in Number, viz. the Ballance, Leaver, Pulley, Wheel, Wedge, compound Machines, or Engines, are innumerable. The word engine used as a synonym both by Harris and in later language derives ultimately from Latin ingenium ingenuity, an invention, perhaps the first example of a human made device designed to manage power is the hand axe, made by chipping flint to form a wedge. A wedge is a machine that transforms lateral force and movement of the tool into a transverse splitting force. The idea of a simple machine originated with the Greek philosopher Archimedes around the 3rd century BC, who studied the Archimedean simple machines, lever, pulley and he discovered the principle of mechanical advantage in the lever. Later Greek philosophers defined the five simple machines and were able to roughly calculate their mechanical advantage. Heron of Alexandria in his work Mechanics lists five mechanisms that can set a load in motion, lever, windlass, pulley, wedge, and screw, however the Greeks understanding was limited to statics and did not include dynamics or the concept of work. In 1586 Flemish engineer Simon Stevin derived the mechanical advantage of the inclined plane, the complete dynamic theory of simple machines was worked out by Italian scientist Galileo Galilei in 1600 in Le Meccaniche. He was the first to understand that simple machines do not create energy, the classic rules of sliding friction in machines were discovered by Leonardo da Vinci, but remained unpublished in his notebooks. They were rediscovered by Guillaume Amontons and were developed by Charles-Augustin de Coulomb. The word mechanical refers to the work that has produced by machines or the machinery
8.
Latin
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Latin is a classical language belonging to the Italic branch of the Indo-European languages. The Latin alphabet is derived from the Etruscan and Greek alphabets, Latin was originally spoken in Latium, in the Italian Peninsula. Through the power of the Roman Republic, it became the dominant language, Vulgar Latin developed into the Romance languages, such as Italian, Portuguese, Spanish, French, and Romanian. Latin, Italian and French have contributed many words to the English language, Latin and Ancient Greek roots are used in theology, biology, and medicine. By the late Roman Republic, Old Latin had been standardised into Classical Latin, Vulgar Latin was the colloquial form spoken during the same time and attested in inscriptions and the works of comic playwrights like Plautus and Terence. Late Latin is the language from the 3rd century. Later, Early Modern Latin and Modern Latin evolved, Latin was used as the language of international communication, scholarship, and science until well into the 18th century, when it began to be supplanted by vernaculars. Ecclesiastical Latin remains the language of the Holy See and the Roman Rite of the Catholic Church. Today, many students, scholars and members of the Catholic clergy speak Latin fluently and it is taught in primary, secondary and postsecondary educational institutions around the world. The language has been passed down through various forms, some inscriptions have been published in an internationally agreed, monumental, multivolume series, the Corpus Inscriptionum Latinarum. Authors and publishers vary, but the format is about the same, volumes detailing inscriptions with a critical apparatus stating the provenance, the reading and interpretation of these inscriptions is the subject matter of the field of epigraphy. The works of several hundred ancient authors who wrote in Latin have survived in whole or in part and they are in part the subject matter of the field of classics. The Cat in the Hat, and a book of fairy tales, additional resources include phrasebooks and resources for rendering everyday phrases and concepts into Latin, such as Meissners Latin Phrasebook. The Latin influence in English has been significant at all stages of its insular development. From the 16th to the 18th centuries, English writers cobbled together huge numbers of new words from Latin and Greek words, dubbed inkhorn terms, as if they had spilled from a pot of ink. Many of these words were used once by the author and then forgotten, many of the most common polysyllabic English words are of Latin origin through the medium of Old French. Romance words make respectively 59%, 20% and 14% of English, German and those figures can rise dramatically when only non-compound and non-derived words are included. Accordingly, Romance words make roughly 35% of the vocabulary of Dutch, Roman engineering had the same effect on scientific terminology as a whole
9.
Walking
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Walking is one of the main gaits of locomotion among legged animals, and is typically slower than running and other gaits. Walking is defined by an inverted pendulum gait in which the vaults over the stiff limb or limbs with each step. This applies regardless of the number of limbs - even arthropods, with six, eight or more limbs, the word walk is descended from the Old English wealcan to roll. In humans and other bipeds, walking is generally distinguished from running in only one foot at a time leaves contact with the ground. In contrast, running begins when both feet are off the ground with each step and this distinction has the status of a formal requirement in competitive walking events. The most effective method to walking from running is to measure the height of a persons centre of mass using motion capture or a force plate at midstance. During walking, the centre of mass reaches a height at midstance, while during running. This distinction, however, only true for locomotion over level or approximately level ground. For walking up grades above 9%, this no longer holds for some individuals. Running humans and animals may have contact periods greater than 50% of a cycle when rounding corners. Speed is another factor that distinguishes walking from running, champion racewalkers can average more than 14 kilometres per hour over a distance of 20 kilometres. An average human child achieves independent walking ability at around 11 months old, regular, brisk exercise of any kind can improve confidence, stamina, energy, weight control and life expectancy and reduce stress. It can also reduce the risk of heart disease, strokes, diabetes, high blood pressure, bowel cancer. Life expectancy is also increased even for individuals suffering from obesity or high blood pressure, Walking also improves bone health, especially strengthening the hip bone, and lowering the harmful low-density lipoprotein cholesterol, and raising the useful high-density lipoprotein cholesterol. Studies have found that walking may also help prevent dementia and Alzheimers, the Centers for Disease Control and Preventions fact sheet on the Relationship of Walking to Mortality Among U. S. Adults with Diabetes states that those with diabetes who walked for 2 or more hours a week lowered their mortality rate from all causes by 39 per cent. Walking lengthened the life of people with diabetes regardless of age, sex, race, body mass index, length of time since diagnosis, and presence of complications or functional limitations. It has been suggested there is a relationship between the speed of walking and health, and that the best results are obtained with a speed of more than 2.5 mph
10.
Running
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Running is a method of terrestrial locomotion allowing humans and other animals to move rapidly on foot. Running is a type of gait characterized by a phase in which all feet are above the ground. The term running can refer to any of a variety of speeds ranging from jogging to sprinting and it is assumed that the ancestors of mankind developed the ability to run for long distances about 2.6 million years ago, probably in order to hunt animals. Competitive running grew out of religious festivals in various areas, records of competitive racing date back to the Tailteann Games in Ireland in 1829 BCE, while the first recorded Olympic Games took place in 776 BCE. Running has been described as the worlds most accessible sport and it is thought that human running evolved at least four and a half million years ago out of the ability of the ape-like Australopithecus, an early ancestor of humans, to walk upright on two legs. The theory as first proposed used comparative physiological evidence and the habits of animals when running, indicating the likelihood of this activity as a successful hunting method. Further evidence from observation of modern-day hunting practice also indicated this likelihood, according to Sears scientific investigation of the Nariokotome Skeleton provided further evidence for the Carrier theory. Competitive running grew out of religious festivals in various such as Greece, Egypt, Asia. The Tailteann Games, an Irish sporting festival in honor of the goddess Tailtiu, dates back to 1829 BCE, the origins of the Olympics and Marathon running are shrouded by myth and legend, though the first recorded games took place in 776 BCE. Seeing that they were moving and running, from their running nature they were called Gods or runners. Running gait can be divided into two phases in regard to the extremity, stance and swing. These can be divided into absorption, propulsion, initial swing. Due to the nature of running gait, no certain point is assumed to be the beginning. However, for simplicity it will be assumed that absorption and footstrike mark the beginning of the cycle in a body already in motion. Footstrike occurs when a portion of the foot makes initial contact with the ground. Common footstrike types include forefoot, midfoot and heel strike types and these are characterized by initial contact of the ball of the foot, ball and heel of the foot simultaneously and heel of the foot respectively. During this time the hip joint is undergoing extension from being in maximal flexion from the swing phase. For proper force absorption, the joint should be flexed upon footstrike
11.
Jumping
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Jumping or leaping is a form of locomotion or movement in which an organism or non-living mechanical system propels itself through the air along a ballistic trajectory. Some animals, such as the kangaroo, employ jumping as their form of locomotion, while others, such as frogs. Jumping is also a key feature of various activities and sports, including the long jump, high jump, all jumping involves the application of force against a substrate, which in turn generates a reactive force that propels the jumper away from the substrate. Any solid or liquid capable of producing a force can serve as a substrate. Examples of the latter include dolphins performing traveling jumps, and Indian skitter frogs executing standing jumps from water, jumping organisms are rarely subject to significant aerodynamic forces and, as a result, their jumps are governed by the basic physical laws of ballistic trajectories. Consequently, while a bird may jump into the air to initiate flight, no movement it performs once airborne is considered jumping, following the moment of launch, a jumper will traverse a parabolic path. The launch angle and initial launch velocity determine the distance, duration. The maximum possible horizontal travel distance occurs at a angle of 45 degrees. Muscles do physical work, adding energy to the jumpers body over the course of a jumps propulsive phase. This results in a kinetic energy at launch that is proportional to the square of the jumpers speed, the more work the muscles do, the greater the launch velocity and thus the greater the acceleration and the shorter the time interval of the jumps propulsive phase. Mechanical power and the distance over which that power is applied are the key determinants of jump distance, as a result, many jumping animals have long legs and muscles that are optimized for maximal power according to the force-velocity relationship of muscles. The maximum power output of muscles is limited, however, to circumvent this limitation, many jumping species slowly pre-stretch elastic elements, such as tendons or apodemes, to store work as strain energy. Such elastic elements can release energy at a higher rate than equivalent muscle mass. A jumper may be stationary or moving when initiating a jump. In a jump from stationary, all of the required to accelerate the body through launch is done in a single movement. In a moving jump or running jump, the jumper introduces additional vertical velocity at launch while conserving as much momentum as possible. Consequently, jumpers are able to jump greater distances when starting from a run, animals use a wide variety of anatomical adaptations for jumping. Aquatic species rarely display any particular specializations for jumping and those that are good jumpers usually are primarily adapted for speed, and execute moving jumps by simply swimming to the surface at a high velocity
12.
Mammal
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Mammals are any vertebrates within the class Mammalia, a clade of endothermic amniotes distinguished from reptiles by the possession of a neocortex, hair, three middle ear bones and mammary glands. All female mammals nurse their young with milk, secreted from the mammary glands, Mammals include the largest animals on the planet, the great whales. The basic body type is a quadruped, but some mammals are adapted for life at sea, in the air, in trees. The largest group of mammals, the placentals, have a placenta, Mammals range in size from the 30–40 mm bumblebee bat to the 30-meter blue whale. With the exception of the five species of monotreme, all modern mammals give birth to live young, most mammals, including the six most species-rich orders, belong to the placental group. The largest orders are the rodents, bats and Soricomorpha, the next three biggest orders, depending on the biological classification scheme used, are the Primates, the Cetartiodactyla, and the Carnivora. Living mammals are divided into the Yinotheria and Theriiformes There are around 5450 species of mammal, in some classifications, extant mammals are divided into two subclasses, the Prototheria, that is, the order Monotremata, and the Theria, or the infraclasses Metatheria and Eutheria. The marsupials constitute the group of the Metatheria, and include all living metatherians as well as many extinct ones. Much of the changes reflect the advances of cladistic analysis and molecular genetics, findings from molecular genetics, for example, have prompted adopting new groups, such as the Afrotheria, and abandoning traditional groups, such as the Insectivora. The mammals represent the only living Synapsida, which together with the Sauropsida form the Amniota clade, the early synapsid mammalian ancestors were sphenacodont pelycosaurs, a group that produced the non-mammalian Dimetrodon. At the end of the Carboniferous period, this group diverged from the line that led to todays reptiles. Some mammals are intelligent, with some possessing large brains, self-awareness, Mammals can communicate and vocalize in several different ways, including the production of ultrasound, scent-marking, alarm signals, singing, and echolocation. Mammals can organize themselves into fission-fusion societies, harems, and hierarchies, most mammals are polygynous, but some can be monogamous or polyandrous. They provided, and continue to provide, power for transport and agriculture, as well as commodities such as meat, dairy products, wool. Mammals are hunted or raced for sport, and are used as model organisms in science, Mammals have been depicted in art since Palaeolithic times, and appear in literature, film, mythology, and religion. Defaunation of mammals is primarily driven by anthropogenic factors, such as poaching and habitat destruction, Mammal classification has been through several iterations since Carl Linnaeus initially defined the class. No classification system is accepted, McKenna & Bell and Wilson & Reader provide useful recent compendiums. Though field work gradually made Simpsons classification outdated, it remains the closest thing to a classification of mammals
13.
Macropodidae
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Macropods are marsupials belonging to the family Macropodidae, the kangaroo family, which includes kangaroos, wallabies, tree-kangaroos, pademelons, quokkas, and several others. Macropods are native to the Australian continent, before European settlement of Australia, about 65 species of macropods existed. Six species have become extinct and a further eleven have been greatly reduced in numbers. Other species became extinct after the Australian Aborigines arrived and before the Europeans arrived, although omnivorous kangaroos lived in the past, modern macropods are herbivorous. Some are browsers, but most are grazers and are equipped with appropriately specialised teeth for cropping and grinding up fibrous plants, in particular grasses and sedges. In general, macropods have a broad, straight row of cutting teeth at the front of the mouth, no teeth. Like many Macropodiformes, early kangaroos had plagiaulacoids, but these converted into normal molars in more derived species, most species have four molars and, when the last pair is too worn to be of use, the animals starve to death. The dental formula for macropods is 3. 0-1.2.41.0.2, the details of organisation are quite different, but the end result is somewhat similar. This fact might prevent the establishment of methanogenic archaea, which has found in low levels in tammar wallabies. Metagenomic analysis revealed that the foregut of tammar wallabies mainly contains bacteria belonging to the phyla Firmicutes, Bacteroides, among proteobacteria populations of the Succinivibrionaceae family are overrepresented and may contribute to low methane emissions. Macropods vary in size considerably, but most have large hind legs and long. The term macropod comes from the Greek for large foot and is appropriate, most have very long, the fourth toe is very large and strong, the fifth toe moderately so, the second and third are fused, and the first toe is usually missing. Their short front legs have five separate digits, some macropods have seven carpal bones instead of the usual eight in mammals. All have relatively small heads and most have large ears, except for tree-kangaroos, the young are born very small and the pouch opens forward. The unusual development of the legs is optimised for economical long-distance travel at fairly high speed. In consequence, most of the energy required for each hop is provided free by the action of the tendons. The main limitation on an ability to leap is not the strength of the muscles in the hindquarters, it is the ability of the joints. In addition, the action is linked to breathing
14.
Dipodomyinae
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Dipodomyinae is a subfamily of heteromyid rodents, the kangaroo rats and mice. Dipodomyines, as implied by both their common and scientific names, are bipedal, they also jump exceptionally well, kangaroo rats and mice are native to desert and semidesert ecosystems of western North America from southern Canada to central Mexico. They are generally herbivorous foragers, and dig and live in burrows, dipodomyinae is the sister group of a Perognathinae-Heteromyinae clade, the two are estimated to have split about 22-24 million years ago. The most recent common ancestor of extant dipodomyines is thought to have lived 15-16 Ma ago, the most recent common ancestors of extant members of Dipodomys and Microdipodops are thought to have lived 10-11 and 7-8 Ma ago, respectively
15.
Pedetes
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Pedetes is a genus of rodent, the springhares, in the family Pedetidae. Members of the genus are distributed across southern and Eastern Africa, a number of species both extant and extinct are classified in the genus Pedetes. These rodents are generally nocturnal and sleep through the day in burrows they dig and they feed on foliage, roots and other vegetable matter, and occasionally arthropods. Outside the burrow they usually move around by hopping on their hind legs, when only one springhare species was recognized, it was listed as vulnerable by the IUCN in 1996 due to an approximately 20% decrease in the population over the previous ten years. This has been caused by hunting and the loss of habitat. However, the trend has not persisted, and both species are now listed as Species of Least Concern
16.
Hopping mice
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A hopping mouse is any of about ten different Australian native mice in the genus Notomys. They are rodents, not marsupials, and their ancestors are thought to have arrived from Asia about 5 million years ago. All are brown or fawn, fading to grey or white underneath, have very long tails and, as the common name implies. Half of the hopping mouse species have become extinct since European colonisation, the primary cause is probably predation from introduced foxes or cats, coupled with competition for food from introduced rabbits and cattle. A hopping mouses primary diet is seeds, an Australian hopping mouse can concentrate urine to as high as 10,000 mOsm/L. This allows it to survive in the desert without drinking water, the spinifex hopping mouse occurs throughout the central and western Australian arid zones, occupying both spinifex-covered sand flats and stabilised sand dunes, and loamy mulga and melaleuca flats. The extinct short-tailed hopping mouse was the largest species at around 100 g, the northern hopping mouse is found only in coastal northern Australia, from Arnhem Land to the Cobourg Peninsula. The fawn hopping mouse is found on the sparsely vegetated gibber plains and claypans of the Lake Eyre Basin. Small at around 30 to 50 g, and light in colour, it is gregarious and feeds at night on seeds, insects, some small dusky hopping mouse populations retain a slender hold on existence in the Strzelecki Desert. They feed, mostly on seeds, at night and shelter in deep vertical burrows, the long-tailed hopping mouse is an extinct species, which was widespread in the drier regions of southern and central Australia. It dug burrows in stiff, clay soils and it liked raisins, but was not a pest to the stores of settlers. Only a handful of specimens were collected and the last record dates from 1901, the extinct big-eared hopping mouse lived in the Moore River area of south-western Australia. The last record dates from 19 July 1843, mitchells hopping mouse is the largest extant member of the genus. It occurs throughout much of semi-arid Southern Australia and is considered to be unthreatened, although its range has been reduced through habitat disturbance. The introduction of cattle to the Darling Downs has greatly changed the ecology of the region, the great hopping mouse is extinct. It is known only from skulls found in owl pellets in the Flinders Ranges, some pellets also include bones of the introduced house mouse—indicating that it survived into historic times, possibly the second half of the 19th century. From the skull, it appears to have relatively large. From the location of the deposits it is assumed that it preferred clay rather than sandy soils and it is notable that very few of the clay-living hopping mice have survived European settlement, sand dunes apparently providing a more secure refuge from competitors and predators
17.
Pangolin
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Pangolins are mammals of the order Pholidota. These species range in size from 30 to 100 cm, a number of extinct pangolin species are also known. Pangolins have large, protective keratin scales covering their skin, they are the only mammals with this adaptation. They live in trees or burrows, depending on the species. Pangolins are nocturnal, and their diet consists of mainly ants and they tend to be solitary animals, meeting only to mate and produce a litter of one to three offspring which are raised for about two years. Pangolins are threatened by hunting and heavy deforestation of their natural habitats, the name pangolin comes from the Malay word pengguling, meaning something that rolls up. The physical appearance of a pangolin is marked by large, hardened, overlapping scales, which are soft on newborn pangolins. They are made of keratin, the material of which human fingernails. The pangolins scaled body is comparable to a cone or globe artichoke. It can curl up into a ball when threatened, with its overlapping scales acting as armor, the scales are sharp, providing extra defense from predators. Pangolins can also emit a chemical from glands near the anus. They have short legs, with sharp claws which they use for burrowing into termite and ant mounds, large pangolins can extend their tongues as much as 40 cm, with a diameter of only 0.5 cm. Most pangolins are nocturnal animals that use their sense of smell to find insects. The long-tailed pangolin is also active by day, while species of pangolins spend most of the daytime sleeping. Arboreal pangolins live in trees, whereas the ground-dwelling species dig tunnels underground. Some pangolins walk with their front claws bent under the foot pad, furthermore, some exhibit a bipedal stance for some behaviors and may walk a few steps bipedally. Most of their diet consists of species of ants and termites and may be supplemented by other insects. They are somewhat particular and tend to only one or two species of insects, even when many species are available to them
18.
Australopithecine
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Australopithecines are generally all species in the related Australopithecus and Paranthropus genera, and it typically includes Kenyanthropus, Ardipithecus, and Praeanthropus. All these related species are now sometimes collectively classified as a subtribe of the Hominini tribe called Australopithecina and they are the extinct, close relatives of humans and, with the extant genus Homo, comprise the human clade. Members of the clade, i. e. the Hominini after the split from the chimpanzees, are now called homonina. The terms australopithecine, et al. come from a classification as members of a distinct subfamily. Members of Australopithecus are sometimes referred to as the gracile australopithecines, humans may have descended from australopithecine ancestors and the genus Ardipithecus is a possible ancestor of the australopithecines. Phylogeny of subtribe Australopithecina according to Briggs & Crowther 2008, p.124 and they have a high brachial index when compared to other hominins, and they exhibit greater sexual dimorphism than members of Homo or Pan but less so than Gorilla or Pongo. It is thought that they averaged heights of 1. 2–1.5 metres, the brain size may have been 350 cc to 600 cc. Most scientists maintain that one of the species evolved into the Homo genus in Africa around two million years ago. Nearly every possible species has been suggested as a likely candidate, presently, it appears that A. garhi has the potential to occupy this coveted place in paleoanthropology, but the lack of fossil evidence is a serious problem. Another problem presents itself in the fact that it has very difficult to assess which hominid represents the first member of the genus Homo. Without knowing this, it is not possible to determine which species of australopithecine may have been ancestral to Homo, marc Verhaegen has argued that an australopithecine species could have also been ancestral to the Pan genus. A minority held viewpoint among palaeoanthropologists is that australopithecines moved outside of Africa, a notable proponent of this theory is Jens Lorenz Franzen, formerly Head of Paleoanthropology at the Research Institute Senckenberg. In 1957, an Early Pleistocene Chinese fossil tooth of unknown province was described as resembling P. robustus, three fossilized molars from Jianshi, China were later identified as belonging to an Australopithecus species. However further examination questioned this interpretation, Zhang argued the Jianshi teeth, but, Wolpoff notes that in China persistent claims of australopithecine or australopithecine-like remains continue. Dawn of Humanity Human taxonomy Informative lecture on Australopithecines
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Homo
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The genus is between 2 and 3 million years old, taken to emerge with the appearance of Homo habilis. It is derived from the genus Australopithecus, which itself had previously split from the lineage of Pan, taxonomically, Homo is the only genus assigned to the subtribe Hominina which, with the subtribes Australopithecina and Panina, comprise the tribe Hominini. All species of the genus Homo plus those species of the australopithecines that arose after the split from Pan are called hominins, Homo erectus appeared about two million years ago in East Africa and, in several early migrations, it spread throughout Africa and Eurasia. It was likely the first hominin to live in a hunter-gatherer society, the subspecies Homo sapiens sapiens or anatomically modern humans emerged about 200,000 years ago in East Africa. DNA analysis provides evidence of interbreeding between archaic and modern humans. See Hominidae for an overview of taxonomy, the Latin noun homō means human being or man in the generic sense of human being, mankind. The binomial name Homo sapiens was coined by Carl Linnaeus, names for other species of the genus were introduced beginning in the second half of the 19th century. Even today, the genus Homo has not been properly defined, since the early human fossil record began to slowly emerge from the earth, the boundaries and definitions of the genus Homo have been poorly defined and constantly in flux. Because there was no reason to think it would ever have any additional members, the discovery of Neanderthal brought the first addition. The genus Homo was given its name to suggest that its member species can be classified as human. Many such names are now dubbed as synonyms with Homo, including Pithecanthropus, Protanthropus, Sinanthropus, Cyphanthropus, Africanthropus, Telanthropus, Atlanthropus, classifying the genus Homo into species and subspecies is subject to incomplete information and remains poorly done. Some recently extinct species in the genus Homo are only recently discovered, john Edward Gray was an early advocate of classifying taxa by designating tribes and families. Several species, including Australopithecus garhi, Australopithecus sediba, Australopithecus africanus and these species have morphological features that align them with Homo, but there is no consensus as to which gave rise to Homo. The advent of Homo was traditionally taken to coincide with the first use of stone tools, the emergence of Homo also coincides roughly with the onset of Quaternary glaciation, the beginning of the current ice age. A fossil mandible fragment dated to 2.8 million years ago which may represent a stage between Australopithecus and Homo was discovered in 2015 in Afar, Ethiopia. Some authors would push the development of Homo past 3 Mya, the most salient physiological development between the earlier australopithecine species and Homo is the increase in cranial capacity, from about 450 cm3 in A. garhi to 600 cm3 in H. habilis. Within the genus Homo, cranial capacity again doubled from H. habilis through Homo ergaster or H. erectus to Homo heidelbergensis by 0.6 million years ago, the cranial capacity of H. heidelbergensis overlaps with the range found in modern humans. Homo erectus has often been assumed to have developed anagenetically from Homo habilis from about 2 million years ago
20.
Triassic
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The Triassic is a geologic period and system which spans 50.9 million years from the end of the Permian Period 252.17 million years ago, to the beginning of the Jurassic Period 201.3 Mya. The Triassic is the first period of the Mesozoic Era, both the start and end of the period are marked by major extinction events. Therapsids and archosaurs were the terrestrial vertebrates during this time. A specialized subgroup of archosaurs, called dinosaurs, first appeared in the Late Triassic, the vast supercontinent of Pangaea existed until the mid-Triassic, after which it began to gradually rift into two separate landmasses, Laurasia to the north and Gondwana to the south. The global climate during the Triassic was mostly hot and dry, however, the climate shifted and became more humid as Pangaea began to drift apart. The end of the period was marked by yet another mass extinction, the Triassic-Jurassic extinction event. The Triassic is usually separated into Early, Middle, and Late Triassic Epochs, from the east, along the equator, the Tethys sea penetrated Pangaea, causing the Paleo-Tethys Ocean to be closed. Later in the mid-Triassic a similar sea penetrated along the equator from the west, the remaining shores were surrounded by the world-ocean known as Panthalassa. All the deep-ocean sediments laid down during the Triassic have disappeared through subduction of oceanic plates, thus, the supercontinent Pangaea was rifting during the Triassic—especially late in that period—but had not yet separated. In North America, for example, marine deposits are limited to a few exposures in the west, thus Triassic stratigraphy is mostly based on organisms that lived in lagoons and hypersaline environments, such as Estheria crustaceans. At the beginning of the Mesozoic Era, Africa was joined with Earths other continents in Pangaea, Africa shared the supercontinents relatively uniform fauna which was dominated by theropods, prosauropods and primitive ornithischians by the close of the Triassic period. Late Triassic fossils are found throughout Africa, but are common in the south than north. The time boundary separating the Permian and Triassic marks the advent of an event with global impact. At Paleorrota geopark, located in Rio Grande do Sul, Brazil, in these formations, one of the earliest dinosaurs, Staurikosaurus, as well as the mammal ancestors Brasilitherium and Brasilodon have been discovered. The Triassic continental interior climate was hot and dry, so that typical deposits are red bed sandstones and evaporites. Pangaeas large size limited the effect of the global ocean, its continental climate was highly seasonal, with very hot summers. The strong contrast between the Pangea supercontinent and the global ocean triggered intense cross-equatorial monsoons, the best studied of such episodes of humid climate, and probably the most intense and widespread, was the Carnian Pluvial Event. On land, the vascular plants included the lycophytes, the dominant cycadophytes, ginkgophyta, ferns, horsetails
21.
Archosaur
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Archosaurs are a group of diapsid amniotes whose living representatives consist of birds and crocodilians. This group also includes all extinct dinosaurs, extinct crocodilian relatives. Archosauria, the clade, is a crown group that includes the most recent common ancestor of living birds. It includes two clades, Pseudosuchia, which includes crocodilians and their extinct relatives, and Ornithosuchia. Archosaurs can be distinguished from other tetrapods on the basis of synapomorphies, or shared characteristics. The simplest and most widely agreed synapomorphies of archosaurs include teeth set in sockets, antorbital and mandibular fenestrae, being set in sockets, the teeth were less likely to be torn loose during feeding. This feature is responsible for the name thecodont, which used to apply to many Triassic archosaurs. Some archosaurs, such as birds, are secondarily toothless, antorbital fenestrae reduced the weight of the skull, which was relatively large in early archosaurs, rather like that of modern crocodilians. Mandibular fenestrae may also have reduced the weight of the jaw in some forms, the fourth trochanter provides a large site for the attachment of muscles on the femur. There is some debate about when archosaurs first appeared and those who classify the Permian reptiles Archosaurus rossicus and/or Protorosaurus speneri as true archosaurs maintain that archosaurs first appeared in the late Permian. The earliest archosaurs were rauisuchians, such as Scythosuchus and Tsylmosuchus, synapsids were the dominant land vertebrates throughout the Permian, but most perished in the Permian-Triassic extinction event. Very few large synapsids survived the event, although one form, Lystrosaurus, but archosaurs quickly became the dominant land vertebrates in the early Triassic. The two most commonly suggested explanations for this are, Archosaurs made more progress towards erect limbs than synapsids. An objection to this explanation is that became dominant while they still had sprawling or semi-erect limbs, similar to those of Lystrosaurus. The early Triassic was predominantly arid, because most of the land was concentrated in the supercontinent Pangaea. Archosaurs were probably better at conserving water than early synapsids because, Modern diapsids excrete uric acid and it is reasonable to suppose that archosaurs also excreted uric acid, and therefore were good at conserving water. The aglandular skins of diapsids would also have helped to conserve water, Modern mammals excrete urea, which requires a lot of water to keep it dissolved. Their skins also contain many glands, which also lose water, assuming that early synapsids had similar features, e. g. as argued by the authors of Palaeos, they were at a disadvantage in a mainly arid world
22.
Crocodile
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Crocodiles or true crocodiles are large aquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. Crocodylinae, all of whose members are considered true crocodiles, is classified as a biological subfamily, a broader sense of the term crocodile, Crocodylidae that includes Tomistoma, is not used in this article. The term crocodile here applies only to the species within the subfamily of Crocodylinae, although they appear to be similar to the untrained eye, crocodiles, alligators and the gharial belong to separate biological families. The gharial having a narrow snout is easier to distinguish, while morphological differences are more difficult to spot in crocodiles and alligators. The most obvious differences are visible in the head with crocodiles having narrower and longer heads, with a more V-shaped than a U-shaped snout compared to alligators. Also, when the mouth is closed, the large fourth tooth in the lower jaw fits into a constriction in the upper jaw. For hard-to-distinguish specimens, the tooth is the most reliable feature to define the family that the species belongs to. Crocodiles have more webbing on the toes of the feet and can better tolerate saltwater due to specialized salt glands for filtering out salt. Another trait that separates crocodiles from other crocodilians is their higher levels of aggression. Crocodile size, morphology, behaviour and ecology somewhat differs between species, however, they have many similarities in these areas as well. All crocodiles are semiaquatic and tend to congregate in freshwater such as rivers, lakes, wetlands. They are carnivorous animals, feeding mostly on such as fish, reptiles, birds and mammals. All crocodiles are tropical species that, unlike alligators, are sensitive to cold. They separated from other crocodilians during the Eocene epoch, about 55 million years ago, many species are at the risk of extinction, some being classified as critically endangered. The word crocodile comes from the Ancient Greek κροκόδιλος, lizard, used in the phrase ho krokódilos tou potamoú, there are several variant Greek forms of the word attested, including the later form κροκόδειλος found cited in many English reference works. In the Koine Greek of Roman times, crocodilos and crocodeilos would have been pronounced identically, crocodilos or crocodeilos is a compound of krokè, and drilos/dreilos, although drilos is only attested as a colloquial term for penis. It is ascribed to Herodotus, and supposedly describes the habits of the Egyptian crocodile. The form crocodrillus is attested in Medieval Latin and it is not clear whether this is a medieval corruption or derives from alternative Greco-Latin forms
23.
Dinosaur
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Dinosaurs are a diverse group of reptiles of the clade Dinosauria that first appeared during the Triassic. Although the exact origin and timing of the evolution of dinosaurs is the subject of active research and they became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201 million years ago. Their dominance continued through the Jurassic and Cretaceous periods and ended when the Cretaceous–Paleogene extinction event led to the extinction of most dinosaur groups 66 million years ago, until the late 20th century, all groups of dinosaurs were believed to be extinct. As such, birds were the dinosaur lineage to survive the mass extinction event. This article deals primarily with non-avian dinosaurs, Dinosaurs are a varied group of animals from taxonomic, morphological 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 both extant species and fossil remains, while dinosaurs were ancestrally bipedal, many extinct groups included quadrupedal species, and some were able to shift between these stances. Elaborate display structures such as horns or crests are common to all dinosaur groups, evidence suggests that egg laying and nest building are additional traits shared by all dinosaurs.7 meters and heights of 18 meters and were the largest land animals of all time. Still, the idea that dinosaurs were uniformly gigantic is a misconception based in part on preservation bias, as large. Many dinosaurs were small, Xixianykus, for example, was only about 50 cm long. Through the first half of the 20th century, before birds were recognized to be dinosaurs, most of the community believed dinosaurs to have been sluggish. Most research conducted since the 1970s, however, has indicated that all dinosaurs were active animals with elevated metabolisms and numerous adaptations for social interaction. The large sizes of some groups, as well as their seemingly monstrous and fantastic nature, have ensured dinosaurs regular appearance in best-selling books and films. Persistent public enthusiasm for the animals has resulted in significant funding for dinosaur science, the term is derived from the Greek words δεινός and σαῦρος. Though the taxonomic name has often interpreted as a reference to dinosaurs teeth, claws. Instead, dinosaurs, like many forms of reptile sub-groups, did not exhibit characteristics which were traditionally regarded as reptilian. Under phylogenetic nomenclature, dinosaurs are usually defined as the group consisting of Triceratops, Neornithes, their most recent common ancestor, Birds are now recognized as being the sole surviving lineage of theropod dinosaurs. In traditional taxonomy, birds were considered a class that had evolved from dinosaurs
24.
Bird
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Birds, a subgroup of Reptiles, are the last living examples of Dinosaurs. Birds live worldwide and range in size from the 5 cm bee hummingbird to the 2.75 m ostrich. They rank as the class of tetrapods with the most living species, at ten thousand. Birds are the closest living relatives of crocodilians, the fossil record indicates that birds evolved from feathered ancestors within the theropod group of saurischian dinosaurs. True birds first appeared during the Cretaceous period, around 100 million years ago, Birds, especially those in the southern continents, survived this event and then migrated to other parts of the world while diversifying during periods of global cooling. Primitive bird-like dinosaurs that lie outside class Aves proper, in the broader group Avialae, have been found dating back to the mid-Jurassic period, around 170 million years ago. Birds have wings which are more or less developed depending on the species, the digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have evolved for swimming. Many species annually migrate great distances, Birds are social, communicating with visual signals, calls, and bird songs, and participating in such social behaviours as cooperative breeding and hunting, flocking, and mobbing of predators. The vast majority of species are socially monogamous, usually for one breeding season at a time, sometimes for years. Other species have breeding systems that are polygynous or, rarely, Birds produce offspring by laying eggs which are fertilised through sexual reproduction. They are usually laid in a nest and incubated by the parents, most birds have an extended period of parental care after hatching. Some birds, such as hens, lay eggs even when not fertilised, songbirds, parrots, and other species are popular as pets. Guano is harvested for use as a fertiliser, Birds prominently figure throughout human culture. About 120–130 species have become extinct due to human activity since the 17th century, human activity threatens about 1,200 bird species with extinction, though efforts are underway to protect them. Recreational birdwatching is an important part of the ecotourism industry, the first classification of birds was developed by Francis Willughby and John Ray in their 1676 volume Ornithologiae. Carl Linnaeus modified that work in 1758 to devise the taxonomic classification system currently in use, Birds are categorised as the biological class Aves in Linnaean taxonomy. Phylogenetic taxonomy places Aves in the dinosaur clade Theropoda, Aves and a sister group, the clade Crocodilia, contain the only living representatives of the reptile clade Archosauria
25.
Lizard
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Lizards are a widespread group of squamate reptiles, with over 6,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic as it excludes the snakes which are also squamates, Lizards typically have four legs feet and external ears, though some are legless, while snakes lack both of these characteristics. Lizards and snakes share a movable quadrate bone, distinguishing them from the sphenodonts, Lizards form about 60% of all the species of extant non-avian reptiles. Some extinct varanids reached great size, The giant monitor Megalania is estimated to have reached up to 7 m long, vision, including color vision, is particularly well developed in most lizards. Most lizards communicate using body language, using specific postures, gestures, and movements to define territory, resolve disputes, some species of lizards also use pheromones or bright colors, such as the iridescent patches on the belly of Sceloporus. These colors are visible to predators, so are often hidden on the underside or between scales and only revealed when necessary. The particular innovation in this respect is the dewlap, a colored patch of skin on the throat. When a display is needed, a lizard can erect the hyoid bone of its throat, anoles are particularly famous for this display, with each species having specific colors, including patterns only visible under ultraviolet light, as many lizards can see UV light. Lizard tails are often a different and dramatically more vivid color than the rest of the body so as to potential predators to strike for the tail first. Many lizards, including geckos and skinks, are capable of shedding part of their tails through a process called autotomy. This is an example of the pars pro toto principle, sacrificing a part for the whole, the detached tail writhes and wiggles, creating a deceptive sense of continued struggle, distracting the predators attention from the fleeing prey animal. The lizard partially regenerates its tail over a period of weeks, a 2014 research identified 326 genes involved in the regeneration of lizard tails. The new section contains cartilage rather than bone, and the skin may be discolored compared to the rest of the body, most lizards are oviparous, though in some species the eggs are retained until the live young emerge. Parthenogenesis occurs in at least 50 species and may be more widespread in the group. Sexual selection in lizards shows evidence of mate choice, favouring males display fitness indicators. However, doubt has been raised over the age of Tikiguania because it is almost indistinguishable from modern agamid lizards, the Tikiguania remains may instead be late Tertiary or Quaternary in age, having been washed into much older Triassic sediments. Lizards are most closely related to the Rhynchocephalia, which appeared in the Late Triassic, mitochondrial phylogenetics suggest that the first lizards evolved in the late Permian. It had been thought on the basis of data that iguanid lizards diverged from other squamates very early on
26.
Gibbon
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Gibbons are apes in the family Hylobatidae. The family historically contained one genus, but now is split into four genera and 18 species, gibbons occur in tropical and subtropical rainforests from eastern Bangladesh and northeast India to southern China and Indonesia. Also called the smaller apes or lesser apes, gibbons differ from great apes in being smaller, exhibiting low sexual dimorphism, in certain anatomical details, they superficially more closely resemble monkeys than great apes do, but like all apes, gibbons are tailless. Gibbons also display pair-bonding, maintaining the same mate for life, gibbons are masters of their primary mode of locomotion, brachiation, swinging from branch to branch for distances up to 15 m, at speeds as high as 55 km/h. They can also make leaps up to 8 m, and walk bipedally with their arms raised for balance and they are the fastest and most agile of all tree-dwelling, nonflying mammals. Depending on species and sex, gibbons fur coloration varies from dark to light brown shades, Gibbon species include the siamang, the white-handed or lar gibbon, and the hoolock gibbons. Whole genome molecular dating analyses indicate that the gibbon lineage diverged from that of great apes around 16.8 million years ago, adaptive divergence associated with chromosomal rearrangements led to rapid radiation of the four genera 5-7 Mya. Whole genome analysis suggests divergence of Hylobates pileatus from Hylobates moloch 1. 5-3.0 Mya, the extinct Bunopithecus sericus is a gibbon or gibbon-like ape which, until recently, was thought to be closely related to the hoolock gibbons. The family is divided into four genera based on their diploid chromosome number, Hylobates, Hoolock, Nomascus and these morphological ambiguities have led to hybrids in zoos. Interspecific hybrids, hybrids within a genus, are suspected to occur in wild gibbons where their ranges overlap. However, no records exist of fertile hybrids between different gibbon genera, either in the wild or in captivity, one unique aspect of a gibbons anatomy is the wrist, which functions something like a ball and socket joint, allowing for biaxial movement. This greatly reduces the amount of energy needed in the arm and torso. Gibbons also have long hands and feet, with a cleft between the first and second digits of their hands. Their fur is black, gray, or brownish, often with white markings on hands, feet. Some species have a throat sac, which inflates and serves as a resonating chamber when the animals call. This structure can become large in some species, sometimes equaling the size of the animals head. Their voices are more powerful than that of any human singer. Gibbon skulls and teeth resemble those of the apes
27.
Indriidae
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The Indriidae are a family of strepsirrhine primates. They are medium- to large-sized lemurs, with four teeth in the toothcomb instead of the usual six. Indriids, like all lemurs, live exclusively on the island of Madagascar, the 10 extant Indriidae species vary considerably in size. Not counting the length of their tails, the avahis are only 30 cm in length, the tail of the indri is only a stub, while avahi and the sifaka tails are as long as their bodies. Their fur is long and mostly from whitish over reddish up to grey and their black faces, however, are always bald. The hind legs are longer than their fore limbs, their hands are long and thin, all species are arboreal, though they do come to the ground occasionally. When on the ground, they stand upright and move with short hops forward, in the trees, though, they can make extraordinary leaps and are extremely agile, able to change direction from tree to tree. Like most leaf eaters, they adjust for the low nutrient content of their food by long rests, often, they can be seen lying stretched on trees sunning themselves. Indriidae live together in family federations up to 15 animals, communicating with roars, Indriidae are herbivores, eating mostly leaves, fruits, and flowers. Like some other herbivores, they have a large cecum, containing bacteria that ferment cellulose, allowing for more efficient digestion of plant matter. They have fewer teeth than other lemurs, with the dental formula of,2.1.2.32.1.2.3 Females and males usually mate monogamously for many years. Mostly at the end of the dry season, their four- to five-month gestation ends with the birth of a single offspring, the 19 living species in the family are divided into three genera
28.
Quadrupedalism
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Quadrupedalism or pronograde posture is a form of terrestrial locomotion in animals using four limbs or legs. An animal or machine that moves in a quadrupedal manner is known as a quadruped. The majority of quadrupeds are vertebrate animals, including such as cattle, dogs and cats. Few other animals are quadrupedal, though a few birds like the shoebill sometimes use their wings to itself after lunging at prey. Although the words quadruped and tetrapod are both derived from terms meaning four-footed, they have distinct meanings, a tetrapod is any member of the taxonomic unit Tetrapoda whereas a quadruped actually uses four limbs for locomotion. Not all tetrapods are quadrupeds and not all quadrupeds are tetrapods, the distinction between quadrupeds and tetrapods is important in evolutionary biology, particularly in the context of tetrapods whose limbs have adapted to other roles. All of these animals are tetrapods, but none is a quadruped, even snakes, whose limbs have become vestigial or lost entirely, are nevertheless tetrapods. Most quadrupedal animals are tetrapods but there are a few exceptions, for instance, among the insects, the praying mantis is a quadruped. In July 2005, in rural Turkey, scientists discovered five Kurdish siblings who had learned to walk naturally on their hands, unlike chimpanzees, which ambulate on their knuckles, the Kurdish siblings walked on their palms, allowing them to preserve the dexterity of their fingers. Many people, especially practitioners of Parkour and Freerunning and Georges Héberts Natural Method, kenichi Ito is a Japanese man famous for speed running on four limbs. Quadrupedalism is sometimes referred to as being on all fours, and is observed in crawling especially by infants, bigDog is a dynamically stable quadruped robot created in 2005 by Boston Dynamics with Foster-Miller, the NASA Jet Propulsion Laboratory, and the Harvard University Concord Field Station. Also by NASA JPL, in collaboration with University of California, Santa Barbara Robotics Lab, is RoboSimian, with emphasis on stability and it has been demonstrated at the DARPA Robotics Challenge. Bipedalism Orthograde posture Family may provide evolution clue - BBC News
29.
Red kangaroo
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The red kangaroo is the largest of all kangaroos, the largest terrestrial mammal native to Australia, and the largest extant marsupial. It is found across mainland Australia, avoiding only the fertile areas in the south, the east coast. This species is a large kangaroo with long, pointed ears. Males have short, red-brown fur, fading to buff below. Females are smaller males and are blue-grey with a brown tinge, pale gray below. It has two forelimbs with small claws, two muscular hind-limbs, which are used for jumping, and a tail which is often used to create a tripod when standing upright. Females are considerably smaller, with a length of 85–105 cm. Females can weigh from 18 to 40 kg, while males weigh around twice as much at 55 to 90 kg. The average red kangaroo stands approximately 1.5 m tall to the top of the head in upright posture, large mature males can stand more than 1.8 m tall, with the largest confirmed one having been around 2.1 m tall and weighed 91 kg. The red kangaroo maintains its internal temperature at a point of homeostasis about 36 °C using a variety of physical, physiological, and behavioral adaptations. These include having a layer of fur, being less active and staying in the shade when temperatures are high, panting, sweating. The red kangaroos range of vision is approximately 300°, due to the position of its eyes, the red kangaroo ranges throughout western and central Australia. Its range encompasses scrubland, grassland, and desert habitats and it typically inhabits open habitats with some trees for shade. Red kangaroos are capable of conserving water and selecting enough fresh vegetation to survive in an arid environment. The kangaroo’s kidneys efficiently concentrate urine, particularly during summer, red kangaroo primarily eat green vegetation, particularly fresh grasses and forbs, and can get enough even when most plants look brown and dry. One study of kangaroos in Central Australia found that green grass makes up 75–95% of the diet and this grass continues to be green into the dry season. Kangaroos also primarily consumed this species, along with Enneapogon avanaceus, during dry times, kangaroos search for green plants by staying on open grassland and near watercourses. However, some perennial chenopods, such as round-leaf chenopod Kochia are avoided even when abundant, at times, red kangaroos congregate in large numbers, in areas with much forage, these groups can number as much as 1,500 individuals
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Cheetah
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The cheetah /ˈtʃiːtə/ is a large felid of the subfamily Felinae that occurs mainly in eastern and southern Africa and a few parts of Iran. The only extant member of the genus Acinonyx, the cheetah was first described by Johann Christian Daniel von Schreber in 1775. The cheetah is characterised by a body, deep chest, spotted coat, a small rounded head, black tear-like streaks on the face, long thin legs. Its lightly built, slender form is in sharp contrast with the robust build of the big cats, the cheetah reaches nearly 70 to 90 cm at the shoulder, and weighs 21–72 kg. Though taller than the leopard, it is smaller than the lion. Basically yellowish tan or rufous to white, the coat is uniformly covered with nearly 2,000 solid black spots. Cheetahs are active mainly during the day, with hunting their major activity, adult males are sociable despite their territoriality, forming groups called coalitions. Females are not territorial, they may be solitary or live with their offspring in home ranges, carnivores, cheetah mainly prey upon antelopes and gazelles. They will stalk their prey to within 100–300 metres, charge towards it and kill it by tripping it during the chase, the cheetahs body is specialised for speed, it is the fastest land animal. Cheetahs are induced ovulators, breeding throughout the year, gestation is nearly three months long, resulting in a litter of typically three to five cubs. Weaning occurs at six months, siblings tend to stay together for some time, Cheetah cubs face higher mortality than most other mammals, especially in the Serengeti region. Cheetahs inhabit a variety of habitats – dry forests, scrub forests, thanks to its prowess at hunting, the cheetah was tamed and used to kill game at hunts in the past. The animal has been depicted in art, literature, advertising. Classified as vulnerable by the International Union for Conservation of Nature, several African countries have taken steps to improve the standards of cheetah conservation. The vernacular name cheetah is derived from the Hindi word चीता, the first recorded use of this word has been dated back to 1610. An alternative name for the cheetah is hunting leopard, the scientific name of the cheetah is Acinonyx jubatus. The generic name Acinonyx could have originated from the combination of two Greek words, akinetos means motionless, and onyx means claw, a rough translation of the word would be non-moving claws, a reference to the limited retractability of the claws of the cheetah relative to other cats. The specific name jubatus means maned in Latin, referring to the dorsal crest of this animal, the cheetah is the only extant species of the genus Acinonyx
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Endurance running hypothesis
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The endurance running hypothesis is the hypothesis that the evolution of certain human characteristics can be explained as adaptations to long distance running. The hypothesis suggests that endurance running played an important role for early hominins in obtaining food, researchers have proposed that endurance running began as an adaptation for scavenging and later for persistence hunting. Much research has been geared towards the mechanics of how bipedal walking has evolved in the genus Homo, however, little research has been conducted to examine how the specific adaptations for running emerged, and how they influenced human evolution. The bit of research that has focused on human running provides much evidence for bodily function and structures that improve running only and this suggests that running was an adaptation, not that it came about as a byproduct of walking. Running and walking incorporated different biomechanisms, walking requires an inverted pendulum where the bodys center of mass is shifted over the extended leg, to exchange potential and kinetic energy with each step. Running involves a mass spring mechanism to potential and kinetic energy, with the use of tendons. Tendons and ligaments are elastic tissues that store energy and they are stretched and then release energy as they recoil. This mass spring mechanism becomes less costly at faster speeds and is therefore more efficient than the inverted pendulum of walking mechanics when traveling at greater speeds. Tendons and ligaments, however, do not provide benefits in walking. Ground forces and body pitching movement is less of an issue in the walking gait, in response to the destabilization of the running gait, the human body appears to have evolved adaptations to increase stabilization, as well as for the mass-spring mechanism in general. These adaptations, described below, are all evidence for selection for endurance running, many researchers compare the skeletal structures of early hominins such as Australopithecus to those of Homo in order to identify structural differences that may be significant to endurance running. Nuchal ligament, Because the head is decoupled from the shoulders, the nuchal ligament is an important evolved feature in head stabilization. It starts at the midline of the occiput and connects to the upper trapezius, the ability to see traces of ligaments in archaeological findings is rare because they degrade quickly and often leave no trace. In the case of the ligament, a trace of its existence is left with the presence of the skull ridge. Because neither Australopithecus nor Pan had the skull ridge, it has concluded that this feature is unique to Homo. This stabilization is unnecessary in walking, limb length and mass, Homo has longer legs relative to body mass, which helps to decrease energetic costs of running, as time in contact with the ground increases. There is also a decrease in mass of distal parts of limbs of humans, which is known to decrease costs in endurance running. Additionally, the mass of the upper body limbs in Homo has decreased considerably, relative to body mass
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Kangaroo rat
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Kangaroo rats, small rodents of genus Dipodomys, are native to western North America. The common name derives from their bipedal form and they hop in a manner similar to the much larger kangaroo, but developed this mode of locomotion independently, like several other clades of rodents. Kangaroo rats are four-toed heteromyid rodents with big hind legs, small front legs, adults typically weigh between 70 and 170 g. The tails of rats are longer than both their bodies and their heads. Another notable feature of kangaroo rats are their fur-lined cheek pouches, the coloration of kangaroo rats varies from cinnamon buff to dark gray, depending on the species. There is also variation in length with one of the largest species, the banner-tailed kangaroo rat being six inches in body length. Sexual dimorphism exists in all species, with males being larger than females, Kangaroo rats often leap a distance of 6 feet, and reportedly up to 9 feet at speeds up to almost 10 feet/sec, or 10 kph. They can quickly change their direction between jumps, the rapid locomotion of the banner-tailed kangaroo rat may minimize energy cost and predation risk. Its use of a move-freeze mode may also make it less conspicuous to nocturnal predators, Kangaroo rats live in arid and semi-arid areas particularly on sandy or soft soils which are suitable for burrowing. They can, however, vary in both range and habitat. In particular, Merriams kangaroo rats live in areas of low rainfall and humidity and they can be found in areas of varying elevation, ranging from below sea level to about 4500 feet. They live in areas of soils, including clays, gravel and rocks. Merriams kangaroo rats live in hot and dry areas and so must conserve water and they do this in part by lowering their metabolic rate, which reduces loss of water through their skin and respiratory system. They obtain enough water from the oxidation of the seeds they eat to survive. Banner-tailed kangaroo rats live in grasslands and scrublands. They live in dry areas but have more available to them than Merriams kangaroo rats. All kangaroo rat species are sensitive to temperatures and remain in their burrows during rain storms. Kangaroo rats are preyed on by coyotes, foxes, badgers, weasels, owls, Kangaroo rats are primarily seed eaters
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Standing
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Standing, also referred to as orthostasis, is a human position in which the body is held in an upright position and supported only by the feet. Although seemingly static, the body rocks slightly back and forth from the ankle in the sagittal plane, the sway of quiet standing is often likened to the motion of an inverted pendulum. At ease refers to the military position of standing with legs slightly apart. In modeling, model at ease refers to the standing with one leg straight, with the majority of the weight on it. Standing posture relies on dynamic rather than static balance, the human center of mass is in front of the ankle, and unlike in tetrapods, the base of support is narrow, consisting of only two feet. A static pose would cause humans to fall forward onto the face, in addition, there are constant external perturbations, such as breezes, and internal perturbations that come from respiration. Erect posuture requires adjustment and correction, there are many mechanisms in the body that are suggested to control this, e. g. a spring action in muscles, higher control from the nervous system or core muscles. Humans begin to stand between 8 and 12 months of age, traditionally, such correction was explained by the spring action of the muscles, a local mechanism taking place without the intervention of the central nervous system. Recent studies, however, show that this action by itself is insufficient to prevent a forward fall. Also, human sway is too complicated to be explained by spring action. According to current theory, the system continually and unconsciously monitors our direction. The vertical body axis alternates between tilting forward and backward, before each tilt reaches the tipover point the nervous system counters with a signal to reverse direction. Sway also occurs in the hip and there is a winding and unwinding of the lower back. An analogy would be a ball that volleys back and forth between two players without touching the ground, the muscle exertion required to maintain an aligned standing posture is crucial but minimal. Electromyography has detected activity in the muscles of the calves, hips. The core muscles play a role in maintaining stability, the core muscles are deep muscle layers that lie close to the spine and provide structural support. The transverse abdominals wrap around the spine and function as a compression corset, dysfunction in the core muscles has been implicated in back pain. Some investigators have replaced the ankle inverted pendulum analogy with a model of double linked pendulums involving both hip and ankle sway, neither model is accepted as more than an approximation
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Tree-kangaroo
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Tree-kangaroos are marsupials of the genus Dendrolagus, adapted for arboreal locomotion. They inhabit the rainforests of New Guinea, far northeastern Queensland. Most tree-kangaroos are considered threatened due to hunting and habitat destruction and they are the only true arboreal macropods. The evolutionary history of tree-kangaroos begins with a rainforest floor-dwelling pademelon-like ancestor and this ancestor evolved from an arboreal possum-like ancestor as is suspected of all macropodid marsupials in Australia and New Guinea. This generalist strategy allowed the rock-wallabies to easily adapt to malesian rainforest types that were introduced to Australia from Asia during the mid-Miocene, the rock-wallabies that migrated into these introduced forests adapted to spend more time climbing trees. One species in particular, the proserpine rock-wallaby, displays equal preference for climbing trees as for living in rocky outcrops, during the late-Miocene the semi-arboreal rock-wallabies evolved into the now extinct tree-kangaroo genus Bohra. Global cooling during the Pleistocene caused continent-wide drying and rainforest retractions in Australia, seris tree-kangaroo has been described as a subspecies of Dorias tree-kangaroo, but some recent authorities have treated it as a separate species based on its absolute diagnostability. The IUCN provisionally treats D. mayri as a separate species, a population of the tenkile recently discovered from the Bewani Mountains may represent an undescribed subspecies. Although most species are found in areas, several also occur in lowlands. Most tree-kangaroos are considered threatened due to hunting and habitat destruction, because much of their lifestyle involves climbing and jumping between trees, they have evolved an appropriate method of locomotion. Tree-kangaroos thrive in tree tops as opposed to terrestrial kangaroos which survive on mainland Australia, two species of tree-kangaroos are found in Australia, Bennetts, which is found north of the Daintree River and Lumholtzs. Tree-kangaroos have adapted better to regions of high altitudes, at least 15 known subspecies of tree-kangaroo are living in Papua New Guinea and Australia. Tree-kangaroos must find places comfortable and well adapted for breeding, as they give birth to one joey per year. They are known to have one of the most relaxed and leisurely birthing seasons and they breed cautiously in treetops during monsoon season. Their habitats are breeding grounds for danger as they can fall prey to their natural predators, amethystine pythons. Tree-kangaroos are known to be able to live in mountainous regions and low-land locations. The Lumholtzs tree-kangaroo is the smallest of all tree-kangaroos, the Matschies tree-kangaroo has a body and head length of 81 cm, adult males weigh 9–11 kg and adult females weigh 7–9 kg. The grizzled tree-kangaroo grows to a length of 75–90 cm, with males being larger than females
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Ctenosaura
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Ctenosaura is a lizard genus commonly known as spinytail iguanas or Ctenosaurs. The genus is part of the lizard family, Iguanidae and is native to Mexico. The name is derived from two Greek words, ctenos, meaning comb, and saura, meaning lizard, the species range in size from about 12.5 centimetres to well over 1 metre. The distinctive feature of this genus is the presence of enlarged, Ctenosaurs are generally omnivorous, feeding on fruits, flowers, foliage, and small animals. C. similis and C. quinquecarinata are popular as pets, at least two species, Ctenosaura pectinata and Ctenosaura similis, have been introduced into southern areas of Texas and Florida. The world record sprint speed for lizards was attained by the Costa Rican spiny-tailed iguana, the genus Ctenosaura represents the most diverse group of iguanas with 15 currently recognized species and at least two unrecognized species. These species inhabit lowland dry forests, below 1,200 metres elevation, on coasts of Mexico and Central America. All species of Ctenosaura fall within one of seven clades, distributions of these clades fall geographically within well established areas. Closely related species show allopatry whereas species from divergent clades show sympatry, genus Ctenosaura at The Reptile Database Frost, D. E. and R. E. Etheridge A Phylogenetic Analysis and Taxonomy of Iguanian Lizards, R. Etheridge, D. Janies and T. A. Titus Total evidence, sequence alignment, evolution of Polychrotid lizards, and a reclassification of the Iguania. American Museum Novitates 3343,38 pp. Garland, T. Jr.1984, physiological correlates of locomotory performance in a lizard, an allometric approach. PDF IIF Announces Fundraising Campaign Spiny Tailed Iguana Pictures West Coast Iguana Research
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Eudibamus
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Eudibamus is an extinct genus of biped bolosaurid ankyramorph parareptile known from the Free State of Thuringia of central Germany. It had a small size reaching only 25 cm in length. Eudibamus is known only from the holotype MNG8852, an articulated and it was collected from the uppermost part of the Tambach Formation, dating to the Artinskian stage of the Late Cisuralian Series, about 284-279.5 million years ago. It was found in the lowermost formational unit of the Upper Rotliegend Group or Series of the Bromacker Quarry, Eudibamus is claimed to be the first bipedal vertebrate. Eudibamus was first named by David S. Berman, Robert R. Reisz, Diane Scott, henrici, Stuart S. Sumida and Thomas Martens in 2000 and the type species is Eudibamus cursoris. The specific name is derived from the Latin word cursor, for runner
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Crocodilia
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The Crocodilia is an order of mostly large, predatory, semiaquatic reptiles, known as crocodilians. They first appeared 83.5 million years ago in the Late Cretaceous period and are the closest living relatives of birds, as the two groups are the only known survivors of the Archosauria. Members of the total group, the clade Pseudosuchia, appeared about 250 million years ago in the Early Triassic period. The order Crocodilia includes the true crocodiles, the alligators and caimans, although the term crocodiles is sometimes used to refer to all of these, crocodilians is a less ambiguous vernacular term for members of this group. Large, solidly built, lizard-like reptiles, crocodilians have flattened snouts, laterally compressed tails, and eyes, ears. They swim well and can move on land in a high walk and their skin is thick and covered in non-overlapping scales. They have conical, peg-like teeth and a powerful bite and they have a four-chambered heart and, somewhat like birds, a unidirectional looping system of airflow within the lungs, but like other non-avian reptiles they are ectotherms. Crocodilians are found mainly in lowlands in the tropics, but alligators also live in the southeastern United States, Crocodilians are typically solitary and territorial, though cooperative feeding does occur. During breeding, dominant males try to monopolise available females, females lay eggs in holes or in mounds and, unlike most other reptiles, care for their hatched young. Eight species of crocodilians are known to have attacked humans, the largest number of attacks comes from the Nile crocodile. Artistic and literary representations of crocodilians have appeared in cultures around the world since at least Ancient Egypt. Crocodilia and Crocodylia have been used interchangeably for decades starting with Schmidts redescription of the group from the defunct term Loricata. Schmidt used the older term Crocodilia, based on Owens original name for the group, shortly after, Wermuth opted for Crocodylia as the proper name for this redescribed group, basing it on the type genus Crocodylus. Dundee—in a revision of many reptilian and amphibian names—argued strongly for Crocodylia to be the spelling for the group, however, it was not until the advent of cladistics and phylogenetic nomenclature that a more solid justification for assuming one spelling over the other was proposed. Prior to 2003, Crocodilia/Crocodylia was a group that encompassed the modern-day animals as well as their distant relatives now in the larger groups called Crocodylomorpha. Under its current definition Crocodylia is restricted to only the most recent ancestor of todays modern-day crocodilians and this distinction is more important for paleontologists studying crocodilian evolution. As such, the alternate spellings Crocodilia and Crocodylia are still used interchangeably in the neontological literature, Crocodilia appears to be a Latinizing of the Greek κροκόδειλος, which means both lizard and Nile crocodile. Crocodylia, as coined by Wermuth, in regards to the genus Crocodylus appears to be derived from the ancient Greek κρόκη —meaning shingle or pebble—and δρîλος or δρεîλος for worm, the name may refer to the animals habit of basking on the pebbled shores of the Nile
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Eoraptor
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Eoraptor was one of the earliest known dinosaurs, living nearly 231.4 million years ago, during the Late Triassic in Western Gondwana, in the region that is now northwestern Argentina. It was a small sized, lightly-built, bipedal theropod and it is known from several well-preserved skeletons. When first described in 1993, it was considered to be one of the earliest, Eoraptor has heterodont dentition, suggesting that it was omnivorous, and that this feeding strategy had evolved early on in dinosaurs. Eoraptor had a body that grew to about 1 meter in length, with an estimated weight of about 10 kilograms. It had a lightly built skull with a slightly enlarged external naris, like the coelophysoids which would appear millions of years later, Eoraptor had a kink in its upper jaws, between the maxilla and the premaxilla. Sereno et al. observed that the jaw had a mid-mandibular joint. It ran digitigrade, and upright on its hind legs, the femur of the holotype specimen PVSJ512 of Eoraptor is 152 mm, and the tibia is 157 mm, suggesting that it was a fast runner. Its forelimbs are only half the length of its hindlimbs, which would suggest that it was an obligate biped, all of its long bones have hollow shafts. Eoraptor had five digits on each hand, the three longest of which ended in large claws and were used to handle prey. Scientists have surmised that the fourth and fifth digits were too tiny to be of any use in hunting, the ilium is supported by three sacral vertebrae, unlike that of the coeval Herrerasaurus which is supported by only two sacrals, a basal trait. Eoraptor had vertebral centra that are hollow, a present in some of its ancestors. Bonaparte interpreted the large orbital opening in the skull as a juvenile trait. Paul Sereno et al. supported the notion that Eoraptor was an adult specimen based on the closure of sutures in the column. A diagnosis is a statement of the features of an organism that collectively distinguish it from all other organisms. Some, but not all, of the features in a diagnosis are also autapomorphies, an autapomorphy is a distinctive anatomical feature that is unique to a given organism or group. Langer and Michael Benton note that Eoraptor can be distinguished based on the fact that the part of its fibula is extremely transversely compressed. The holotype specimen PVSJ512 was discovered in muddy siltstone from the Cancha de Bochas Member of the Ischigualasto Formation in Argentina, the fossils in this formation were deposited in the Carnian stage of the Triassic period, approximately 235 to 228 million years ago. It took almost 12 months to collect the holotype, which was shipped to the Field Museum of Natural History in Chicago for preparation by William F. Simpson
39.
Iguanodon
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Bernissartensis, which lived from the late Barremian to the earliest Aptian ages in Belgium, Spain, and possibly elsewhere in Europe, between about 126 and 125 million years ago. Distinctive features include large thumb spikes, which were used for defense against predators. The genus was named in 1825 by English geologist Gideon Mantell, based on specimens that are now assigned to Therosaurus. Iguanodon was the type of dinosaur formally named based on fossil specimens. Together with Megalosaurus and Hylaeosaurus, it was one of the three genera originally used to define Dinosauria, the genus Iguanodon belongs to the larger group Iguanodontia, along with the duck-billed hadrosaurs. The taxonomy of this continues to be a topic of study as new species are named or long-standing ones reassigned to other genera. Scientific understanding of Iguanodon has evolved over time as new information has been obtained from fossils, Iguanodon were bulky herbivores that could shift from bipedality to quadrupedality. These animals had large, tall but narrow skulls, with toothless beaks probably covered with keratin, and teeth like those of iguanas, the arms of I. bernissartensis were long and robust, with rather inflexible hands built so that the three central fingers could bear weight. The thumbs were conical spikes that stuck out away from the three main digits, in early restorations, the spike was placed on the animals nose. Later fossils revealed the nature of the thumb spikes, although their exact function is still debated. They could have used for defense, or for foraging for food. The little finger was elongated and dextrous, and could have used to manipulate objects. The phalangeal formula is 2-3-3-2-4, meaning that the innermost finger has two bones, the next has three, etc, the legs were powerful, but not built for running, and each foot had three toes. The backbone and tail were supported and stiffened by ossified tendons, Iguanodon teeth are, as the name suggests, like those of an iguana, but larger. Unlike hadrosaurids, which had columns of replacement teeth, Iguanodon only had one replacement tooth at a time for each position. The upper jaw held up to 29 teeth per side, with none at the front of the jaw, and the lower jaw 25, the numbers differ because teeth in the lower jaw are broader than those in the upper. Iguanodon gives its name to the unranked clade Iguanodontia, a very populous group of ornithopods with many species known from the Middle Jurassic to the Late Cretaceous. Aside from Iguanodon, the members of the clade include Dryosaurus, Camptosaurus, Ouranosaurus
40.
Effigia
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Effigia was an archosaur that lived in what is now New Mexico, south-eastern USA. The 2 meter fossil was collected by Edwin H. Colbert in blocks of rock from the Ghost Ranch Quarry, the fossil was rediscovered in January 2006 by graduate student Sterling Nesbitt at the American Museum of Natural History. Nesbitt was opening jackets of blocks in order to find new specimens of Coelophysis, upon finding the remains of Effigia, he instantly recognized this was not a dinosaur and proceeded to track down the rest of the blocks from that area of the quarry. Nesbitt and Mark Norell, curator at the museum, named it Effigia okeeffeae in January 2006 after Georgia OKeeffe, Effigia is noted for its remarkable similarity to ornithomimid dinosaurs. Nesbitt also demonstrated that Shuvosaurus was the animal as Chatterjeea. Within this group, Effigia forms a more exclusive clade with Shuvosaurus. In 2007, Lucas and others suggested Effigia was synonymous with Shuvosaurus, in a January 30,2006 episode of The Colbert Report, Stephen Colbert satirically touted the fossil as disproving the Darwinlutionists. Colbert also believes that the fossil should not have named after Georgia OKeeffe, whose paintings scare the hell out of. In the 2007 3-D IMAX film, Dinosaurs Alive, Nesbitt explains how he discovered Effigia. It is also featured in a sequence where it is chased by a small pack of Coelophysis. Effigia at American Museum of Natural History Fossil Yields Surprise Kin of Crocodiles – New York Times
41.
Pterosaur
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Pterosaurs were flying reptiles of the extinct clade or order Pterosauria. They existed from the late Triassic to the end of the Cretaceous, Pterosaurs are the earliest vertebrates known to have evolved powered flight. Their wings were formed by a membrane of skin, muscle, Early species had long, fully toothed jaws and long tails, while later forms had a highly reduced tail, and some lacked teeth. Many sported furry coats made up of hair-like filaments known as pycnofibers, Pterosaurs spanned a wide range of adult sizes, from the very small anurognathids to the largest known flying creatures of all time, including Quetzalcoatlus and Hatzegopteryx. Pterosaurs are often referred to in the media and by the general public as flying dinosaurs. Like the dinosaurs, and unlike these other reptiles, pterosaurs are more related to birds than to crocodiles or any other living reptile. Pterosaurs are also referred to as pterodactyls, particularly in fiction. Technically, Pterodactyl refers only to members of the genus Pterodactylus, the anatomy of pterosaurs was highly modified from their reptilian ancestors by the adaption to flight. Pterosaur bones were hollow and air-filled, like the bones of birds and they had a keeled breastbone that was developed for the attachment of flight muscles and an enlarged brain that shows specialised features associated with flight. In some later pterosaurs, the backbone over the shoulders fused into a known as a notarium, which served to stiffen the torso during flight. Pterosaur wings were formed by membranes of skin and other tissues, the primary membranes attached to the extremely long fourth finger of each arm and extended along the sides of the body to the ankles. The outer wings were strengthened by closely spaced fibers called actinofibrils, the actinofibrils themselves consisted of three distinct layers in the wing, forming a crisscross pattern when superimposed on one another. The function of the actinofibrils is unknown, as is the material from which they were made. Depending on their composition, they may have been stiffening or strengthening agents in the outer part of the wing. The wing membranes also contained a layer of muscle, fibrous tissue. The pterosaur wing membrane is divided into three basic units, the first, called the propatagium, was the forward-most part of the wing and attached between the wrist and shoulder, creating the leading edge during flight. This membrane may have incorporated the first three fingers of the hand, as evidenced in some specimens, the brachiopatagium was the primary component of the wing, stretching from the highly elongated fourth finger of the hand to the hind limbs. It is generally agreed though that non-pterodactyloid pterosaurs had a broader uro/cruropatagium, a bone unique to pterosaurs, known as the pteroid, connected to the wrist and helped to support a forward membrane between the wrist and shoulder
42.
Radiometric dating
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Radiometric dating or radioactive dating is a technique used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, together with stratigraphic principles, radiometric dating methods are used in geochronology to establish the geological time scale. Among the best-known techniques are radiocarbon dating, potassium-argon dating and uranium-lead dating, by allowing the establishment of geological timescales, it provides a significant source of information about the ages of fossils and the deduced rates of evolutionary change. Radiometric dating is used to date archaeological materials, including ancient artifacts. Different methods of radiometric dating vary in the timescale over which they are accurate, all ordinary matter is made up of combinations of chemical elements, each with its own atomic number, indicating the number of protons in the atomic nucleus. Additionally, elements may exist in different isotopes, with each isotope of an element differing in the number of neutrons in the nucleus, a particular isotope of a particular element is called a nuclide. That is, at point in time, an atom of such a nuclide will undergo radioactive decay. This transformation may be accomplished in a number of different ways, including alpha decay, another possibility is spontaneous fission into two or more nuclides. After one half-life has elapsed, one half of the atoms of the nuclide in question will have decayed into a daughter nuclide or decay product, Isotopic systems that have been exploited for radiometric dating have half-lives ranging from only about 10 years to over 100 billion years. For most radioactive nuclides, the half-life depends solely on nuclear properties and is essentially a constant and it is not affected by external factors such as temperature, pressure, chemical environment, or presence of a magnetic or electric field. The only exceptions are nuclides that decay by the process of capture, such as beryllium-7, strontium-85. For all other nuclides, the proportion of the nuclide to its decay products changes in a predictable way as the original nuclide decays over time. This predictability allows the relative abundances of related nuclides to be used as a clock to measure the time from the incorporation of the original nuclides into a material to the present. The basic equation of radiometric dating requires that neither the parent nuclide nor the product can enter or leave the material after its formation. The possible confounding effects of contamination of parent and daughter isotopes have to be considered and it is therefore essential to have as much information as possible about the material being dated and to check for possible signs of alteration. Precision is enhanced if measurements are taken on multiple samples from different locations of the rock body and this can reduce the problem of contamination. In uranium-lead dating, the diagram is used which also decreases the problem of nuclide loss. Finally, correlation between different isotopic dating methods may be required to confirm the age of a sample, the procedures used to isolate and analyze the parent and daughter nuclides must be precise and accurate
43.
Genus
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A genus is a taxonomic rank used in the biological classification of living and fossil organisms in biology. In the hierarchy of classification, genus comes above species. In binomial nomenclature, the name forms the first part of the binomial species name for each species within the genus. Felis catus and Felis silvestris are two species within the genus Felis, Felis is a genus within the family Felidae. The composition of a genus is determined by a taxonomist, the standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. Moreover, genera should be composed of units of the same kind as other genera. The term comes from the Latin genus, a noun form cognate with gignere, linnaeus popularized its use in his 1753 Species Plantarum, but the French botanist Joseph Pitton de Tournefort is considered the founder of the modern concept of genera. The scientific name of a genus may be called the name or generic epithet. It plays a role in binomial nomenclature, the system of naming organisms. The rules for the names of organisms are laid down in the Nomenclature Codes. The standard way of scientifically describing species and other lower-ranked taxa is by binomial nomenclature, the generic name forms its first half. For example, the gray wolfs binomial name is Canis lupus, with Canis being the name shared by the wolfs close relatives. The specific name is written in lower-case and may be followed by names in zoology or a variety of infraspecific names in botany. Especially with these names, when the generic name is known from context. Because animals are typically only grouped within subspecies, it is written as a trinomen with a third name. Dog breeds, meanwhile, are not scientifically distinguished, there are several divisions of plant species and therefore their infraspecific names generally include contractions explaining the relation. For example, the genus Hibiscus includes hundreds of other species apart from the Rose of Sharon or common garden hibiscus, Rose of Sharon doesnt have subspecies but has cultivars that carry desired traits, such as the bright white H. syriaca Diana. Hawaiian hibiscus, meanwhile, includes several separate species, since not all botanists agree on the divisions or names between species, it is common to specify the source of the name using author abbreviations
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Common descent
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Common descent describes how, in evolutionary biology, a group of organisms share a most recent common ancestor. There is evidence of descent that all life on Earth is descended from the last universal common ancestor. In July 2016, scientists reported identifying a set of 355 genes from the LUCA of all living on Earth. Common ancestry between organisms of different species arises during speciation, in new species are established from a single ancestral population. Organisms which share a more recent common ancestor are more closely related, the most recent common ancestor of all currently living organisms is the last universal ancestor, which lived about 3.9 billion years ago. Chance, one might say, turned out a vast number of individuals, a much greater number showed neither adaptation nor order, these last have all perished. Thus the species which we see today are but a part of all those that a blind destiny has produced. In 1790, Immanuel Kant wrote in Kritik der Urteilskraft that the analogy of animal forms implies a common original type, furthermore, the genetic code is nearly identical for all known lifeforms, from bacteria and archaea to animals and plants. The universality of this code is generally regarded by biologists as definitive evidence in favor of the theory of common descent. Analysis of the differences in the genetic code has also provided support for universal common descent. An example would be Cytochrome c which most organisms actually share, a statistical comparison of various alternative hypotheses has shown that universal common ancestry is significantly more probable than models involving multiple origins. Similarities which have no adaptive relevance cannot be explained by convergent evolution, such evidence has come from two areas, amino acid sequences and DNA sequences. Proteins with the same three-dimensional structure need not have identical amino acid sequences, in certain cases, there are several codons that code for the same amino acid. Thus, if two species use the same codon at the place to specify an amino acid that can be represented by more than one codon. The universality of many aspects of life is often pointed to as supportive evidence to the more compelling evidence listed above. These similarities include the energy carrier adenosine triphosphate, and the fact that all amino acids found in proteins are left-handed. It is, however, possible that these similarities resulted because of the laws of physics and chemistry, rather than common descent. Another important piece of evidence is that it is possible to construct detailed phylogenetic trees mapping out the proposed divisions and it should be noted, however, that the formal test was criticised for not including consideration of convergent evolution, and Theobald has defended the method against this claim
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Marasuchus
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Marasuchus is a genus of basal dinosauriform archosaur which lived during the late Triassic in what is now La Rioja Province, Argentina. Marasuchus was lightly built and small, it had a length of 30–40 cm, height of 10 cm and it was bipedal, walking with an upright gait, like that of modern mammals and birds. Until 2003 Marasuchus was thought to be one of the closest relatives of the dinosaurs, at present it has been supplanted by other dinosauromorphs such as Silesaurus. Nonetheless, Marasuchus remains an important animal for understanding the origin, the formation was dated as being 234 to 236 million years old. Two species have been named, L. talampayensis and L. lilloensis, the genus and type species are regarded as nomina dubia. The species Marasuchus lilloensis was originally described as a species of Lagosuchus. However, in a restudy of Lagosuchus by Sereno and Arcucci and they also noted that the L. lilloensis specimen had limb proportions different from the type species. On this basis, they assigned L. lilloensis to a new genus, Marasuchus
. PMID 20127307.
