A rugby ball is an elongated ellipsoidal ball used in rugby football. Richard Lindon and Bernardo Solano started making balls for Rugby school out of hand stitched, leather casings and pigs’ bladders; the rugby ball's distinctive shape is due to the pig’s bladder, although early balls were more plum-shape than oval. The balls varied in size in the beginning depending upon; until 1870, rugby was played with a near spherical ball with an inner-tube made of a pig's bladder. In 1870 Richard Lindon introduced rubber inner-tubes and because of the pliability of rubber the shape changed from a sphere to an egg. In 1892 the RFU endorsed ovalness as the compulsory shape; the gradual flattening of the ball continued over the years. The introduction of synthetic footballs over the traditional leather balls, in both rugby codes, was governed by weather conditions. If the playing surface was wet, the synthetic ball was used, as it didn't absorb water and become heavy; the leather balls were phased out completely.
The rugby ball used in rugby union is a prolate spheroid elliptical in profile. Traditionally made of brown leather, modern footballs are manufactured in a variety of colors and patterns. A regulation football is 28 -- 58 -- 62 cm in circumference at its widest point, it is inflated to 65.7 -- 68.8 kPa. In 1980, leather-encased balls, which were prone to water-logging, were replaced with balls encased in synthetic waterproof materials; the Gilbert Synergie was the match ball of the 2007 Rugby World Cup. Most of the professional leagues use Adidas, Mitre or Webb Ellis manufactured balls. Rugby league is played with a prolate spheroid shaped football, inflated with nitrogen. A referee will stop play if the ball does not meet the requirements of size and shape. Traditionally made of brown leather, modern footballs are synthetic and manufactured in a variety of colours and patterns. Senior competitions should use light coloured balls to allow spectators to see the ball more easily; the football used in rugby league is known as "international size" or "size 5" and is 27 cm long and 60 cm in circumference at its widest point.
Smaller-sized balls are used for junior versions of the game, such as "Mini" and "Mod". A full size ball weighs between 440 g. Rugby league footballs are more pointed than rugby union footballs and larger than American footballs; the Australian National Rugby League use balls made by Steeden while the Super League use balls made by Rhino Rugby. Steeden is sometimes used as a noun to describe the ball itself. Football, a ball of similar dimensions used in American and Canadian Football
The heavy-footed moa is a species of moa from the family Dinornithidae. This moa was widespread only in the South Island of New Zealand, its habitat was the lowlands, it was a member of the order Struthioniformes. The Struthioniformes are flightless birds with a sternum without a keel, they have a distinctive palate. The origin of these birds is becoming clearer as it is now believed that early ancestors of these birds were able to fly and flew to the southern areas in which they have been found; the heavy-footed moa was about 1.8 m tall, weighed as much as 145 kg. The heavy-footed moa was discovered by W. B. D. Mantell at Awamoa, near Oamaru, the bones were taken by him to England. Bones from multiple birds were used to make a full skeleton, put in the British Museum; the name Dinornis. The heavy-footed moa was found only in the South Island of New Zealand, their range covered much of the eastern side of the island, with a northern and southern variant of the species. They were a lowland species, preferring dry and open habitats such as grasslands and dry forests.
They were absent from mountain habitats, where they were replaced by the crested moa. During the Pleistocene-Holocene warming event, the retreat of glacial ice meant that the heavy-footed moa’s preferred habitat area increased, allowing their distribution across the island to increase as well. Due to its relative isolation before the Polynesian settlers arrived, New Zealand has a unique plant and animal community and had no native terrestrial mammals. Moa filled the ecological niche of large herbivores, filled by mammals elsewhere, until the arrival of the Polynesian settlers and the associated mammalian invasion in the 13th Century; the heavy-footed Moa is thought to have been less abundant than other moa species due to its less frequent representation in the fossil record. Until it was unknown what the diet of the heavy-footed moa consisted of; the fact that it had different head and beak shapes to its contemporaries suggested that it had a different diet of tougher vegetation as suggested by its preferred dry and shrubby habitat.
Specialising in different foods would have allowed it to avoid competition with other moa species which may have shared part of its range. In 2007 Jamie Wood described the gizzard contents of a heavy-footed moa for the first time, they found 21 plant taxa which included Hebe leaves, various seeds and mosses as well as a large amount of twigs and wood, some of which were of a considerable size. This supports the earlier idea that the heavy-footed moa was adapted to consume tough vegetation, but it shows that it had a varied diet and could eat most plant products, including wood; the heavy-footed moa’s only real predator was the Haast's eagle. Brands, Sheila. "Systema Naturae 2000 / Classification, Genus Pachyornis". Project: The Taxonomicon. Retrieved Feb 4, 2009. Davies, S. J. J. F.. "Moas". In Hutchins, Michael. Grzimek's Animal Life Encyclopedia. 8 Birds I Ratites to Hoatzins. Farmington Hills, MI: Gale Group. Pp. 95–98. ISBN 0-7876-5784-0. Olliver, Narena. "Heavy–footed Moa". Birds. New Zealand Birds. Retrieved Feb 15, 2011.
Heavy-footed Moa. Pachyornis elephantopus. By Paul Martinson. Artwork produced for the book Extinct Birds of New Zealand, by Alan Tennyson, Te Papa Press, Wellington, 2006
North Island giant moa
The North Island giant moa is one of two extinct moa in the genus Dinornis. It is a member of the order Dinornithiformes; the Dinorthiformes are flightless birds without a keel. They have a distinctive palate; the origin of these birds is becoming clearer as it is now believed that early ancestors of these birds were able to fly and flew to the southern areas where they have been found. This moa lived on the North Island of New Zealand, lived in the lowlands. Brands, Sheila. "Systema Naturae 2000 / Classification, Genus Dinornis". Project: The Taxonomicon. Retrieved 4 February 2009. Davies, S. J. J. F.. "Moas". In Hutchins, Michael. Grzimek's Animal Life Encyclopedia. 8 Birds I Ratites to Hoatzins. Farmington Hills, MI: Gale Group. Pp. 95–98. ISBN 0-7876-5784-0. Lydekker, Richard. Catalogue of the fossil birds in the British Museum. London: British Museum. P. 224. Retrieved 5 January 2010. North Island Giant Moa. Dinornis Novaezealandiae. By Paul Martinson. Artwork produced for the book Extinct Birds of New Zealand, by Alan Tennyson, Te Papa Press, Wellington, 2006 Holotypes of Dinornis Novaezealandiae in the collection of the Museum of New Zealand Te Papa Tongarewa
A chordate is an animal constituting the phylum Chordata. During some period of their life cycle, chordates possess a notochord, a dorsal nerve cord, pharyngeal slits, an endostyle, a post-anal tail: these five anatomical features define this phylum. Chordates are bilaterally symmetric; the Chordata and Ambulacraria together form the superphylum Deuterostomia. Chordates are divided into three subphyla: Vertebrata. There are extinct taxa such as the Vetulicolia. Hemichordata has been presented as a fourth chordate subphylum, but now is treated as a separate phylum: hemichordates and Echinodermata form the Ambulacraria, the sister phylum of the Chordates. Of the more than 65,000 living species of chordates, about half are bony fish that are members of the superclass Osteichthyes. Chordate fossils have been found from as early as the Cambrian explosion, 541 million years ago. Cladistically, vertebrates - chordates with the notochord replaced by a vertebral column during development - are considered to be a subgroup of the clade Craniata, which consists of chordates with a skull.
The Craniata and Tunicata compose the clade Olfactores. Chordates form a phylum of animals that are defined by having at some stage in their lives all of the following anatomical features: A notochord, a stiff rod of cartilage that extends along the inside of the body. Among the vertebrate sub-group of chordates the notochord develops into the spine, in wholly aquatic species this helps the animal to swim by flexing its tail. A dorsal neural tube. In fish and other vertebrates, this develops into the spinal cord, the main communications trunk of the nervous system. Pharyngeal slits; the pharynx is the part of the throat behind the mouth. In fish, the slits are modified to form gills, but in some other chordates they are part of a filter-feeding system that extracts particles of food from the water in which the animals live. Post-anal tail. A muscular tail that extends backwards behind the anus. An endostyle; this is a groove in the ventral wall of the pharynx. In filter-feeding species it produces mucus to gather food particles, which helps in transporting food to the esophagus.
It stores iodine, may be a precursor of the vertebrate thyroid gland. There are soft constraints that separate chordates from certain other biological lineages, but are not part of the formal definition: All chordates are deuterostomes; this means. All chordates are based on a bilateral body plan. All chordates are coelomates, have a fluid filled body cavity called a coelom with a complete lining called peritoneum derived from mesoderm; the following schema is from the third edition of Vertebrate Palaeontology. The invertebrate chordate classes are from Fishes of the World. While it is structured so as to reflect evolutionary relationships, it retains the traditional ranks used in Linnaean taxonomy. Phylum Chordata †Vetulicolia? Subphylum Cephalochordata – Class Leptocardii Clade Olfactores Subphylum Tunicata – Class Ascidiacea Class Thaliacea Class Appendicularia Class Sorberacea Subphylum Vertebrata Infraphylum incertae sedis Cyclostomata Superclass'Agnatha' paraphyletic Class Myxini Class Petromyzontida or Hyperoartia Class †Conodonta Class †Myllokunmingiida Class †Pteraspidomorphi Class †Thelodonti Class †Anaspida Class †Cephalaspidomorphi Infraphylum Gnathostomata Class †Placodermi Class Chondrichthyes Class †Acanthodii Superclass Osteichthyes Class Actinopterygii Class Sarcopterygii Superclass Tetrapoda Class Amphibia Class Sauropsida Class Synapsida Craniates, one of the three subdivisions of chordates, all have distinct skulls.
They include the hagfish. Michael J. Benton commented that "craniates are characterized by their heads, just as chordates, or all deuterostomes, are by their tails". Most craniates are vertebrates; these consist of a series of bony or cartilaginous cylindrical vertebrae with neural arches that protect the spinal cord, with projections that link the vertebrae. However hagfish have incomplete braincases and no vertebrae, are therefore not regarded as vertebrates, but as members of the craniates, the group from which vertebrates are thought to have evolved; however the cladistic exclusion of hagfish from the vertebrates is controversial, as they ma
In biology, extinction is the termination of an organism or of a group of organisms a species. The moment of extinction is considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point; because a species' potential range may be large, determining this moment is difficult, is done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" after a period of apparent absence. More than 99 percent of all species, amounting to over five billion species, that lived on Earth are estimated to have died out. Estimates on the number of Earth's current species range from 10 million to 14 million, of which about 1.2 million have been documented and over 86 percent have not yet been described. In 2016, scientists reported that 1 trillion species are estimated to be on Earth with only one-thousandth of one percent described. Through evolution, species arise through the process of speciation—where new varieties of organisms arise and thrive when they are able to find and exploit an ecological niche—and species become extinct when they are no longer able to survive in changing conditions or against superior competition.
The relationship between animals and their ecological niches has been established. A typical species becomes extinct within 10 million years of its first appearance, although some species, called living fossils, survive with no morphological change for hundreds of millions of years. Mass extinctions are rare events. Only have extinctions been recorded and scientists have become alarmed at the current high rate of extinctions. Most species that become extinct are never scientifically documented; some scientists estimate that up to half of presently existing plant and animal species may become extinct by 2100. A 2018 report indicated that the phylogenetic diversity of 300 mammalian species erased during the human era since the Late Pleistocene would require 5 to 7 million years to recover. A dagger symbol placed next to the name of a species or other taxon indicates its status as extinct. A species is extinct. Extinction therefore becomes a certainty when there are no surviving individuals that can reproduce and create a new generation.
A species may become functionally extinct when only a handful of individuals survive, which cannot reproduce due to poor health, sparse distribution over a large range, a lack of individuals of both sexes, or other reasons. Pinpointing the extinction of a species requires a clear definition of that species. If it is to be declared extinct, the species in question must be uniquely distinguishable from any ancestor or daughter species, from any other related species. Extinction of a species plays a key role in the punctuated equilibrium hypothesis of Stephen Jay Gould and Niles Eldredge. In ecology, extinction is used informally to refer to local extinction, in which a species ceases to exist in the chosen area of study, but may still exist elsewhere; this phenomenon is known as extirpation. Local extinctions may be followed by a replacement of the species taken from other locations. Species which are not extinct are termed extant; those that are extant but threatened by extinction are referred to as threatened or endangered species.
An important aspect of extinction is human attempts to preserve critically endangered species. These are reflected by the creation of the conservation status "extinct in the wild". Species listed under this status by the International Union for Conservation of Nature are not known to have any living specimens in the wild, are maintained only in zoos or other artificial environments; some of these species are functionally extinct, as they are no longer part of their natural habitat and it is unlikely the species will be restored to the wild. When possible, modern zoological institutions try to maintain a viable population for species preservation and possible future reintroduction to the wild, through use of planned breeding programs; the extinction of one species' wild population can have knock-on effects, causing further extinctions. These are called "chains of extinction"; this is common with extinction of keystone species. A 2018 study indicated that the 6th mass extinction started in the Late Pleistocene could take up to 5 to 7 million years to restore 2.5 billion years of unique mammal diversity to what it was before the human era.
Extinction of a parent species where daughter species or subspecies are still extant is called pseudoextinction or phyletic extinction. The old taxon vanishes, transformed into a successor, or split into more than one. Pseudoextinction is difficult to demonstrate unless one has a strong chain of evidence linking a living species to members of a pre-existing species. For example, it is sometimes claimed that the extinct Hyracotherium, an early horse that shares a common ancestor with the modern horse, is pseudoextinct, rather than extinct, because there are several extant species of Equus, including zebra and donkey. However, as fossil species leave no genetic material behind, one cannot say whether Hyracotherium evolved into more modern horse species or evolved from a common ancestor with modern horses. Pseudoextinction is much easier to demonstrate for larger taxonomic groups; the coelacanth, a fish related to lungfish and tetrapods, was consi
A ratite is any of a diverse group of flightless and large and long-legged birds of the infraclass Palaeognathae. Kiwi, are much smaller and shorter-legged, as well as being the only nocturnal ratites; the systematics of and relationships within the paleognath clade have been in flux. All the flightless members had been assigned to the order Struthioniformes, more regarded as containing only the ostrich; the modern bird superorder Palaeognathae consists of flighted Neotropic tinamous. Unlike other flightless birds, the ratites have no keel on their sternum – hence the name from the Latin ratis. Without this to anchor their wing muscles, they could not fly if they were to develop suitable wings. Recent research has indicated; this implies that flightlessness is a trait that evolved independently multiple times in different ratite lineages. Most parts of the former supercontinent Gondwana have ratites, or did have until the recent past. So did Europe in the Paleocene and Eocene, from where the first flightless paleognaths are known.
Ostriches were present in Asia as as the Holocene, although the genus is thought to have originated in Africa. However, the ostrich order may have evolved in Eurasia. A recent study posits a Laurasian origin for the clade; the African ostrich is the largest living ratite. A large member of this species can be nearly 2.8 metres tall, weigh as much as 156 kilograms, can outrun a horse. Of the living species, the Australian emu is next in height, reaching up to 1.9 metres tall and about 50 kilograms. Like the ostrich, it is a powerful bird of the open plains and woodlands. Native to Australia and the islands to the north are the three species of cassowary. Shorter than an emu, but heavier and solidly built, cassowaries prefer thickly vegetated tropical forest, they can be dangerous when surprised or cornered because of their razor sharp talons. In New Guinea, cassowary eggs are brought back to villages and the chicks raised for eating as a much-prized delicacy, despite the risk they pose to life and limb.
They reach up to 1.7 metres tall and weigh as much as 59 kilograms South America has two species of rhea, large fast-running birds of the Pampas. The larger American rhea grows to about 1.4 metres tall and weighs 15 to 40 kilograms. The smallest ratites are the five species of kiwi from New Zealand. Kiwi are chicken-sized and nocturnal, they nest in deep burrows and use a developed sense of smell to find small insects and grubs in the soil. Kiwi are notable for laying eggs that are large in relation to their body size. A kiwi egg may equal 15 to 20 percent of the body mass of a female kiwi; the smallest species of kiwi is the little spotted kiwi, at 0.9 to 1.9 kilograms and 35 to 45 centimetres. At least nine species of moa lived in New Zealand before the arrival of humans, ranging from turkey-sized to the giant moa Dinornis robustus with a height of 3.7 metres and weighing about 230 kilograms. They became extinct by A. D. 1400 due to hunting by Māori settlers, who arrived around A. D. 1280. Aepyornis maximus, the "elephant bird" of Madagascar, was the heaviest bird known.
Although shorter than the tallest moa, a large A. maximus could weigh over 400 kilograms and stand up to 3 metres tall. Accompanying it were three other species of Aepyornis as well as three species of the smaller genus Mullerornis. All these species went into decline following the arrival of humans on Madagascar around 2000 years ago, were gone by the 17th or 18th century if not earlier. There are two taxonomic approaches to ratite classification: the one applied here combines the groups as families in the order Struthioniformes, while the other supposes that the lineages evolved independently and thus elevates the families to order rank; the longstanding story of their evolution suggests that they share a common flightless ancestor that lived on Gondwana, whose descendants were carried by continental drift to their present locations. Supporting this idea, some studies based on morphology, immunology and DNA sequencing has indicated that ratites are monophyletic. Cracraft's biogeographic vicariance hypothesis suggests that ancestral flightless paleognaths, the ancestors of ratites, were present and widespread in Gondwana during the Late Cretaceous.
As the supercontinent fragmented due to plate tectonics, they were carried by plate movements to their current positions and evolved into the species present today. The earliest known ratite fossils date to the Paleocene epoch about 56 million years ago. However, more primitive paleognaths are known from several million years earlier, the classification and membership of the Ratitae itself is uncertain; some of the earliest ratites occur in Europe. Recent analyses of genetic variation between the ratites do not support this simple picture; the ratites may have diverged from one another too to share a common Gondwanan ancestor. The Middle Eocene ratites such as Palaeotis and Remiornis from Central Europe may imply that the "out-of-Gondwana" hypothesis is oversimplified. Furthermore, recent analysis of twenty nuclear genes has indicated that the flighted tinamous cluster within the ratites, thus demonstrating that ratites are a paraphyletic group; the authors say the data "unequivocally places tinamous within ratites".
A study using forty novel nuclear l
Anomalopteryx is an extinct bird genus known colloquially as the lesser moa, little bush moa, or bush moa. It weighed 30 kilograms, it inhabited small sections of the South Island of New Zealand. Its habitat was lowland conifer, broad-leafed, beech forests, it is a member of the order Dinornithiformes. The Dinornithiformes are flightless birds with a sternum without a keel, they have a distinctive palate. The most complete remains, a articulated skeleton with substantial mummified tissue were discovered in 1980 in Lake Echo Valley, east of Te Anau, Southland, it is now in Invercargill. Brands, Sheila. "Systema Naturae 2000 / Classification, Genus Anomalopteryx". Project: The Taxonomicon. Retrieved Feb 4, 2009. Davies, S. J. J. F.. "Moas". In Hutchins, Michael. Grzimek's Animal Life Encyclopedia. 8 Birds I Ratites to Hoatzins. Farmington Hills, MI: Gale Group. Pp. 95–98. ISBN 0-7876-5784-0. Little Bush Moa. Anomalopteryx didiformis. By Paul Martinson. Artwork produced for the book Extinct Birds of New Zealand by Alan Tennyson, Te Papa Press, Wellington, 2006