1.
Precambrian
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The Precambrian is the earliest period of Earths history, set before the current Phanerozoic Eon. The Precambrian is a supereon that is subdivided into three eons of the time scale. It spans from the formation of Earth about 4.6 billion years ago to the beginning of the Cambrian Period, about 541 million years ago, the Precambrian accounts for 89% of geologic time. Relatively little is known about the Precambrian, despite it making up roughly seven-eighths of the Earths history, the Precambrian fossil record is poorer than that of the succeeding Phanerozoic, and fossils from that time are of limited biostratigraphic use. This is because many Precambrian rocks have been metamorphosed, obscuring their origins, while others have been destroyed by erosion. A stable crust was apparently in place by 4,412 Ma, the term Precambrian is recognized by the International Commission on Stratigraphy as a general term including the Archean and Proterozoic eons. It is still used by geologists and paleontologists for general discussions not requiring the more specific eon names and it was briefly called the Cryptozoic eon. A specific date for the origin of life has not been determined, carbon found in 3.8 billion year old rocks from islands off western Greenland may be of organic origin. Well-preserved microscopic fossils of bacteria older than 3.46 billion years have found in Western Australia. Probable fossils 100 million years older have been found in the same area, there is a fairly solid record of bacterial life throughout the remainder of the Precambrian. The oldest fossil evidence from that era of such complex life comes from the Lantian formation of the Ediacarian period, a very diverse collection of soft-bodied forms is found in a variety of locations worldwide and date to between 635 and 542 Ma. These are referred to as Ediacaran or Vendian biota, hard-shelled creatures appeared toward the end of that time span, marking the beginning of the Phanerozoic era. By the middle of the following Cambrian period, a diverse fauna is recorded in the Burgess Shale. The explosion in diversity of lifeforms during the early Cambrian is called the Cambrian explosion of life, while land seems to have been devoid of plants and animals, cyanobacteria and other microbes formed prokaryotic mats that covered terrestrial areas. Evidence of the details of plate motions and other activity in the Precambrian has been poorly preserved. It is generally believed that small proto-continents existed prior to 4280 Ma, the supercontinent, known as Rodinia, broke up around 750 Ma. A number of glacial periods have been identified going as far back as the Huronian epoch, one of the best studied is the Sturtian-Varangian glaciation, around 850–635 Ma, which may have brought glacial conditions all the way to the equator, resulting in a Snowball Earth. The atmosphere of the early Earth is not well understood, most geologists believe it was composed primarily of nitrogen, carbon dioxide, and other relatively inert gases, and was lacking in free oxygen
2.
Cambrian
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The Cambrian Period was the first geological period of the Paleozoic Era, of the Phanerozoic Eon. The Cambrian lasted 55.6 million years from the end of the preceding Ediacaran Period 541 million years ago to the beginning of the Ordovician Period 485.4 mya and its subdivisions, and its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latinised form of Cymru, the Welsh name for Wales, as a result, our understanding of the Cambrian biology surpasses that of some later periods. The rapid diversification of lifeforms in the Cambrian, known as the Cambrian explosion, most of the continents were probably dry and rocky due to a lack of vegetation. Shallow seas flanked the margins of several continents created during the breakup of the supercontinent Pannotia, the seas were relatively warm, and polar ice was absent for much of the period. The United States Federal Geographic Data Committee uses a barred capital C ⟨Є⟩ character similar to the capital letter Ukrainian Ye ⟨Є⟩ to represent the Cambrian Period, the proper Unicode character is U+A792 Ꞓ LATIN CAPITAL LETTER C WITH BAR. Despite the long recognition of its distinction from younger Ordovician Period rocks and older Supereon Precambrian rocks, the base of the Cambrian lies atop a complex assemblage of trace fossils known as the Treptichnus pedum assemblage. Pedum in Namibia, Spain and Newfoundland, and possibly, in the western USA, the stratigraphic range of T. pedum overlaps the range of the Ediacaran fossils in Namibia, and probably in Spain. The Cambrian Period followed the Ediacaran Period and was followed by the Ordovician Period, the Cambrian is divided into four epochs and ten ages. Currently only two series and five stages are named and have a GSSP, because the international stratigraphic subdivision is not yet complete, many local subdivisions are still widely used. In some of these subdivisions the Cambrian is divided into three epochs with locally differing names – the Early Cambrian, Middle Cambrian and Furongian, rocks of these epochs are referred to as belonging to the Lower, Middle, or Upper Cambrian. Trilobite zones allow biostratigraphic correlation in the Cambrian, each of the local epochs is divided into several stages. The International Commission on Stratigraphy list the Cambrian period as beginning at 541 million years ago, the lower boundary of the Cambrian was originally held to represent the first appearance of complex life, represented by trilobites. The recognition of small shelly fossils before the first trilobites, and Ediacara biota substantially earlier and this formal designation allowed radiometric dates to be obtained from samples across the globe that corresponded to the base of the Cambrian. Early dates of 570 million years ago quickly gained favour, though the used to obtain this number are now considered to be unsuitable. A more precise date using modern radiometric dating yield a date of 541 ±0.3 million years ago, most continental land was clustered in the Southern Hemisphere at this time, but was drifting north. Large, high-velocity rotational movement of Gondwana appears to have occurred in the Early Cambrian, the sea levels fluctuated somewhat, suggesting there were ice ages, associated with pulses of expansion and contraction of a south polar ice cap. In Baltoscandia a Lower Cambrian transgression transformed large swathes of the Sub-Cambrian peneplain into a epicontinental sea, the Earth was generally cold during the early Cambrian, probably due to the ancient continent of Gondwana covering the South Pole and cutting off polar ocean currents
3.
Ordovician
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The Ordovician is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.2 million years from the end of the Cambrian Period 485.4 million years ago to the start of the Silurian Period 443.8 Mya. Lapworth recognized that the fauna in the disputed strata were different from those of either the Cambrian or the Silurian periods. It received international sanction in 1960, when it was adopted as a period of the Paleozoic Era by the International Geological Congress. Life continued to flourish during the Ordovician as it did in the earlier Cambrian period, invertebrates, namely molluscs and arthropods, dominated the oceans. The Great Ordovician Biodiversification Event considerably increased the diversity of life, fish, the worlds first true vertebrates, continued to evolve, and those with jaws may have first appeared late in the period. Life had yet to diversify on land, about 100 times as many meteorites struck the Earth during the Ordovician compared with today. The Ordovician Period began with a major extinction called the Cambrian–Ordovician extinction event and it lasted for about 42 million years and ended with the Ordovician–Silurian extinction event, about 443.8 Mya which wiped out 60% of marine genera. The dates given are recent radiometric dates and vary slightly from those found in other sources and this second period of the Paleozoic era created abundant fossils that became major petroleum and gas reservoirs. The boundary chosen for the beginning of both the Ordovician Period and the Tremadocian stage is highly significant and it correlates well with the occurrence of widespread graptolite, conodont, and trilobite species. The base of the Tremadocian allows scientists to relate these species not only to each other and this makes it easier to place many more species in time relative to the beginning of the Ordovician Period. A number of terms have been used to subdivide the Ordovician Period. In 2008, the ICS erected an international system of subdivisions. There exist Baltoscandic, British, Siberian, North American, Australian, the Ordovician Period in Britain was traditionally broken into Early, Middle and Late epochs. The corresponding rocks of the Ordovician System are referred to as coming from the Lower, Middle, the Floian corresponds to the lower Arenig, the Arenig continues until the early Darriwilian, subsuming the Dapingian. The Llanvirn occupies the rest of the Darriwilian, and terminates with it at the base of the Late Ordovician. The Sandbian represents the first half of the Caradoc, the Caradoc ends in the mid-Katian, during the Ordovician, the southern continents were collected into Gondwana. Gondwana started the period in equatorial latitudes and, as the period progressed, drifted toward the South Pole, the small continent Avalonia separated from Gondwana and began to move north towards Baltica and Laurentia, opening the Rheic Ocean between Gondwana and Avalonia
4.
Silurian
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The Silurian is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at 443.8 million years ago, to the beginning of the Devonian Period,419.2 Mya. As with other periods, the rock beds that define the periods start and end are well identified. The base of the Silurian is set at a major Ordovician-Silurian extinction event when 60% of marine species were wiped out, a significant evolutionary milestone during the Silurian was the diversification of jawed and bony fish. However, terrestrial life would not greatly diversify and affect the landscape until the Devonian, the Silurian system was first identified by British geologist Sir Roderick Impey Murchison, who was examining fossil-bearing sedimentary rock strata in south Wales in the early 1830s. He named the sequences for a Celtic tribe of Wales, the Silures, inspired by his friend Adam Sedgwick and this naming does not indicate any correlation between the occurrence of the Silurian rocks and the land inhabited by the Silures. As it was first identified, the Silurian series when traced farther afield quickly came to overlap Sedgwicks Cambrian sequence, however, charles Lapworth resolved the conflict by defining a new Ordovician system including the contested beds. An early alternative name for the Silurian was Gotlandian after the strata of the Baltic island of Gotland, the French geologist Joachim Barrande, building on Murchisons work, used the term Silurian in a more comprehensive sense than was justified by subsequent knowledge. He divided the Silurian rocks of Bohemia into eight stages and his interpretation was questioned in 1854 by Edward Forbes, and the later stages of Barrande, F, G and H, have since been shown to be Devonian. Despite these modifications in the groupings of the strata, it is recognized that Barrande established Bohemia as a classic ground for the study of the earliest fossils. The epoch is named for the town of Llandovery in Carmarthenshire, the Wenlock, which lasted from 433.4 ±1.5 to 427.4 ±2.8 mya, is subdivided into the Sheinwoodian and Homerian ages. It is named after Wenlock Edge in Shropshire, England, during the Wenlock, the oldest known tracheophytes of the genus Cooksonia, appear. The first terrestrial animals also appear in the Wenlock, represented by air-breathing millipedes from Scotland. The Ludlow, lasting from 427.4 ±1.5 to 423 ±2.8 mya, comprises the Gorstian stage, lasting until 425.6 million years ago, and it is named for the town of Ludlow in Shropshire, England. The Pridoli, lasting from 423 ±1.5 to 419.2 ±2.8 mya, is the final and it is named after one locality at the Homolka a Přídolí nature reserve near the Prague suburb Slivenec in the Czech Republic. Přídolí is the old name of a field area. The high sea levels of the Silurian and the flat land resulted in a number of island chains. The southern continents remained united during this period, the melting of icecaps and glaciers contributed to a rise in sea level, recognizable from the fact that Silurian sediments overlie eroded Ordovician sediments, forming an unconformity. The continents of Avalonia, Baltica, and Laurentia drifted together near the equator and this event is the Caledonian orogeny, a spate of mountain building that stretched from New York State through conjoined Europe and Greenland to Norway
5.
Devonian
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The Devonian is a geologic period and system of the Paleozoic, spanning 60 million years from the end of the Silurian,419.2 million years ago, to the beginning of the Carboniferous,358.9 Mya. It is named after Devon, England, where rocks from this period were first studied, the first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents, by the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. Various terrestrial arthropods also became well-established, Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fish. The first ray-finned and lobe-finned bony fish appeared, while the placodermi began dominating almost every aquatic environment. The ancestors of all four-limbed vertebrates began adapting to walking on land, as their strong pectoral, in the oceans, primitive sharks became more numerous than in the Silurian and Late Ordovician. The first ammonites, species of molluscs, appeared, trilobites, the mollusk-like brachiopods and the great coral reefs, were still common. The Late Devonian extinction which started about 375 million years ago severely affected marine life, killing off all placodermi, and all trilobites, save for a few species of the order Proetida. The palaeogeography was dominated by the supercontinent of Gondwana to the south, the continent of Siberia to the north, while the rock beds that define the start and end of the Devonian period are well identified, the exact dates are uncertain. According to the International Commission on Stratigraphy, the Devonian extends from the end of the Silurian 419.2 Mya, another common term is Age of the Fishes, referring to the evolution of several major groups of fish that took place during the period. Older literature on the Anglo-Welsh basin divides it into the Downtonian, Dittonian, Breconian and Farlovian stages, in the Late Devonian, by contrast, arid conditions were less prevalent across the world and temperate climates were more common. The Devonian Period is formally broken into Early, Middle and Late subdivisions, the rocks corresponding to those epochs are referred to as belonging to the Lower, Middle and Upper parts of the Devonian System. Early Devonian The Early Devonian lasted from 419.2 ±2.8 to 393.3 ±2.5 and began with the Lochkovian stage, which lasted until the Pragian. It spanned from 410.8 ±2.8 to 407.6 ±2.5, and was followed by the Emsian, which lasted until the Middle Devonian began,393. 3±2.7 million years ago. Middle Devonian The Middle Devonian comprised two subdivisions, first the Eifelian, which gave way to the Givetian 387. 7±2.7 million years ago. Late Devonian Finally, the Late Devonian started with the Frasnian,382.7 ±2.8 to 372.2 ±2.5, during which the first forests took shape on land. The first tetrapods appeared in the record in the ensuing Famennian subdivision. This lasted until the end of the Devonian,358. 9±2.5 million years ago, the Devonian was a relatively warm period, and probably lacked any glaciers
6.
Carboniferous
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The Carboniferous is a geologic period and system that spans 60 million years from the end of the Devonian Period 358.9 million years ago, to the beginning of the Permian Period,298.9 Mya. The name Carboniferous means coal-bearing and derives from the Latin words carbō and ferō, and was coined by geologists William Conybeare and William Phillips in 1822. Based on a study of the British rock succession, it was the first of the system names to be employed. The Carboniferous is often treated in North America as two periods, the earlier Mississippian and the later Pennsylvanian. Terrestrial life was established by the Carboniferous period. Amphibians were the dominant land vertebrates, of one branch would eventually evolve into amniotes. Arthropods were also common, and many were much larger than those of today. Vast swaths of forest covered the land, which would eventually be laid down, the atmospheric content of oxygen also reached their highest levels in geological history during the period, 35% compared with 21% today, allowing terrestrial invertebrates to evolve to great size. A major marine and terrestrial extinction event, the Carboniferous rainforest collapse, occurred in the middle of the period, the later half of the period experienced glaciations, low sea level, and mountain building as the continents collided to form Pangaea. In the United States the Carboniferous is usually broken into Mississippian and Pennsylvanian subperiods, the Silesian is roughly contemporaneous with the late Mississippian Serpukhovian plus the Pennsylvanian. In Britain the Dinantian is traditionally known as the Carboniferous Limestone, the Namurian as the Millstone Grit, and the Westphalian as the Coal Measures and Pennant Sandstone. There was also a drop in south polar temperatures, southern Gondwanaland was glaciated throughout the period and these conditions apparently had little effect in the deep tropics, where lush swamps, later to become coal, flourished to within 30 degrees of the northernmost glaciers. Mid-Carboniferous, a drop in sea level precipitated a major extinction, one that hit crinoids. This sea level drop and the unconformity in North America separate the Mississippian subperiod from the Pennsylvanian subperiod. This happened about 323 million years ago, at the onset of the Permo-Carboniferous Glaciation, the Carboniferous was a time of active mountain-building, as the supercontinent Pangaea came together. The southern continents remained tied together in the supercontinent Gondwana, which collided with North America–Europe along the present line of eastern North America, in the same time frame, much of present eastern Eurasian plate welded itself to Europe along the line of the Ural mountains. Most of the Mesozoic supercontinent of Pangea was now assembled, although North China, the Late Carboniferous Pangaea was shaped like an O. There were two major oceans in the Carboniferous—Panthalassa and Paleo-Tethys, which was inside the O in the Carboniferous Pangaea, other minor oceans were shrinking and eventually closed - Rheic Ocean, the small, shallow Ural Ocean and Proto-Tethys Ocean
7.
Permian
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The Permian is a geologic period and system which spans 46.7 million years from the end of the Carboniferous Period 298.9 million years ago, to the beginning of the Triassic Period 252.2 Mya. It is the last period of the Paleozoic Era, the following Triassic Period belongs to the Mesozoic Era, the concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the city of Perm. The Permian witnessed the diversification of the early amniotes into the groups of the mammals, turtles, lepidosaurs. The world at the time was dominated by two known as Pangaea and Siberia, surrounded by a global ocean called Panthalassa. The Carboniferous rainforest collapse left behind vast regions of desert within the continental interior, amniotes, who could better cope with these drier conditions, rose to dominance in place of their amphibian ancestors. The Permian ended with the Permian–Triassic extinction event, the largest mass extinction in Earths history, in which nearly 90% of marine species and it would take well into the Triassic for life to recover from this catastrophe. Recovery from the Permian-Triassic extinction event was protracted, on land, the term Permian was introduced into geology in 1841 by Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil, the region now lies in the Perm Krai of Russia. This could have in part caused the extinctions of marine species at the end of the period by severely reducing shallow coastal areas preferred by many marine organisms. During the Permian, all the Earths major landmasses were collected into a supercontinent known as Pangaea. The Cimmeria continent rifted away from Gondwana and drifted north to Laurasia, a new ocean was growing on its southern end, the Tethys Ocean, an ocean that would dominate much of the Mesozoic Era. Large continental landmass interiors experience climates with extreme variations of heat and cold, deserts seem to have been widespread on Pangaea. Such dry conditions favored gymnosperms, plants with seeds enclosed in a cover, over plants such as ferns that disperse spores in a wetter environment. The first modern trees appeared in the Permian, the climate in the Permian was quite varied. At the start of the Permian, the Earth was still in an Ice Age, glaciers receded around the mid-Permian period as the climate gradually warmed, drying the continents interiors. In the late Permian period, the drying continued although the temperature cycled between warm and cool cycles, Permian marine deposits are rich in fossil mollusks, echinoderms, and brachiopods. By the close of the Permian, trilobites and a host of other groups became extinct. Terrestrial life in the Permian included diverse plants, fungi, arthropods, the period saw a massive desert covering the interior of Pangaea
8.
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
9.
Jurassic
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The Jurassic is a geologic period and system that spans 56.3 million years from the end of the Triassic Period 201.3 million years ago to the beginning of the Cretaceous Period 145 Mya. The Jurassic constitutes the middle period of the Mesozoic Era, also known as the Age of Reptiles, the start of the period is marked by the major Triassic–Jurassic extinction event. The Jurassic is named after the Jura Mountains within the European Alps, by the beginning of the Jurassic, the supercontinent Pangaea had begun rifting into two landmasses, Laurasia to the north and Gondwana to the south. This created more coastlines and shifted the continental climate from dry to humid, on land, the fauna transitioned from the Triassic fauna, dominated by both dinosauromorph and crocodylomorph archosaurs, to one dominated by dinosaurs alone. The first birds also appeared during the Jurassic, having evolved from a branch of theropod dinosaurs, other major events include the appearance of the earliest lizards, and the evolution of therian mammals, including primitive placentals. Crocodilians made the transition from a terrestrial to a mode of life. The oceans were inhabited by marine reptiles such as ichthyosaurs and plesiosaurs, the chronostratigraphic term Jurassic is directly linked to the Jura Mountains. The name Jura is derived from the Celtic root jor, which was Latinised into juria, the Jurassic period is divided into the Early Jurassic, Middle, and Late Jurassic epochs. The Jurassic System, in stratigraphy, is divided into the Lower Jurassic, Middle, the separation of the term Jurassic into three sections goes back to Leopold von Buch. The Jurassic North Atlantic Ocean was relatively narrow, while the South Atlantic did not open until the following Cretaceous period, the Tethys Sea closed, and the Neotethys basin appeared. Climates were warm, with no evidence of glaciation, as in the Triassic, there was apparently no land over either pole, and no extensive ice caps existed. In contrast, the North American Jurassic record is the poorest of the Mesozoic, the Jurassic was a time of calcite sea geochemistry in which low-magnesium calcite was the primary inorganic marine precipitate of calcium carbonate. Carbonate hardgrounds were thus very common, along with calcitic ooids, calcitic cements, the first of several massive batholiths were emplaced in the northern American cordillera beginning in the mid-Jurassic, marking the Nevadan orogeny. Important Jurassic exposures are found in Russia, India, South America, Japan, Australasia. As the Jurassic proceeded, larger and more groups of dinosaurs like sauropods and ornithopods proliferated in Africa. Middle Jurassic strata are well represented nor well studied in Africa. Late Jurassic strata are also poorly represented apart from the spectacular Tendaguru fauna in Tanzania, the Late Jurassic life of Tendaguru is very similar to that found in western North Americas Morrison Formation. During the Jurassic period, the primary living in the sea were fish
10.
Cretaceous
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The Cretaceous is a geologic period and system that spans 79 million years from the end of the Jurassic Period 145 million years ago to the beginning of the Paleogene Period 66 Mya. It is the last period of the Mesozoic Era, the Cretaceous Period is usually abbreviated K, for its German translation Kreide. The Cretaceous was a period with a warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites and rudists, during this time, new groups of mammals and birds, as well as flowering plants, appeared. The Cretaceous ended with a mass extinction, the Cretaceous–Paleogene extinction event, in which many groups, including non-avian dinosaurs, pterosaurs. The end of the Cretaceous is defined by the abrupt Cretaceous–Paleogene boundary, the name Cretaceous was derived from Latin creta, meaning chalk. The Cretaceous is divided into Early and Late Cretaceous epochs, or Lower and Upper Cretaceous series, in older literature the Cretaceous is sometimes divided into three series, Neocomian, Gallic and Senonian. A subdivision in eleven stages, all originating from European stratigraphy, is now used worldwide, in many parts of the world, alternative local subdivisions are still in use. As with other geologic periods, the rock beds of the Cretaceous are well identified. No great extinction or burst of diversity separates the Cretaceous from the Jurassic and this layer has been dated at 66.043 Ma. A140 Ma age for the Jurassic-Cretaceous boundary instead of the usually accepted 145 Ma was proposed in 2014 based on a study of Vaca Muerta Formation in Neuquén Basin. Víctor Ramos, one of the authors of the study proposing the 140 Ma boundary age sees the study as a first step toward formally changing the age in the International Union of Geological Sciences, due to the high sea level there was extensive space for such sedimentation. Because of the young age and great thickness of the system. Chalk is a type characteristic for the Cretaceous. It consists of coccoliths, microscopically small calcite skeletons of coccolithophores, the group is found in England, northern France, the low countries, northern Germany, Denmark and in the subsurface of the southern part of the North Sea. Chalk is not easily consolidated and the Chalk Group still consists of sediments in many places. The group also has other limestones and arenites, among the fossils it contains are sea urchins, belemnites, ammonites and sea reptiles such as Mosasaurus. In southern Europe, the Cretaceous is usually a marine system consisting of competent limestone beds or incompetent marls
11.
Paleogene
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The Paleogene is a geologic period and system that spans 43 million years from the end of the Cretaceous Period 66 million years ago to the beginning of the Neogene Period 23.03 Mya. It is the beginning of the Cenozoic Era of the present Phanerozoic Eon and this period consists of the Paleocene, Eocene and Oligocene epochs. The terms Paleogene System and lower Tertiary System are applied to the rocks deposited during the Paleogene Period. By dividing the Tertiary Period into two periods instead of directly into five epochs, the periods are more comparable to the duration of periods of the preceding Mesozoic and Paleozoic Eras. The trend was caused by the formation of the Antarctic Circumpolar Current. During the Paleogene, the continued to drift closer to their current positions. India was in the process of colliding with Asia, subsequently forming the Himalayas, the Atlantic Ocean continued to widen by a few centimeters each year. Africa was moving north to meet with Europe and form the Mediterranean, inland seas retreated from North America early in the period. Australia had also separated from Antarctica and was drifting towards Southeast Asia, mammals began a rapid diversification during this period. Some of these mammals would evolve into forms that would dominate the land, while others would become capable of living in marine, specialized terrestrial. Those that took to the oceans became modern cetaceans, while those that took to the trees became primates, the group to which humans belong. Birds, which were well established by the end of the Cretaceous. In comparison to birds and mammals, most other branches of life remained unchanged during this period. As the Earth cooled, tropical plants became less numerous and were now restricted to equatorial regions, deciduous plants, which could survive through the seasonal climates the world was now experiencing, became more common. The Paleogene is notable in the context of offshore oil drilling, and especially in Gulf of Mexico oil exploration and these rock formations represent the current cutting edge of deep-water oil discovery. Lower Tertiary explorations to date include, Kaskida Oil Field Tiber Oil Field Jack 2 Paleogene Microfossils, 180+ images of Foraminifera
12.
Neogene
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The Neogene is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period 23.03 million years ago to the beginning of the present Quaternary Period 2.58 Mya. The Neogene is sub-divided into two epochs, the earlier Miocene and the later Pliocene, some geologists assert that the Neogene cannot be clearly delineated from the modern geological period, the Quaternary. During this period, mammals and birds continued to evolve into modern forms. Early hominids, the ancestors of humans, appeared in Africa near the end of the period, some continental movement took place, the most significant event being the connection of North and South America at the Isthmus of Panama, late in the Pliocene. This cut off the ocean currents from the Pacific to the Atlantic ocean. The global climate cooled considerably over the course of the Neogene, the terms Neogene System and upper Tertiary System describe the rocks deposited during the Neogene Period. The continents in the Neogene were very close to their current positions, the Isthmus of Panama formed, connecting North and South America. The Indian subcontinent continued to collide with Asia, forming the Himalayas, sea levels fell, creating land bridges between Africa and Eurasia and between Eurasia and North America. The global climate became seasonal and continued an overall drying and cooling trend which began at the start of the Paleogene. The ice caps on both poles began to grow and thicken, and by the end of the period the first of a series of glaciations of the current Ice Age began, marine and continental flora and fauna have a modern appearance. The reptile group Choristodera became extinct in the part of the period. Mammals and birds continued to be the dominant terrestrial vertebrates, the first hominids, the ancestors of humans, appeared in Africa and spread into Eurasia. In response to the cooler, seasonal climate, tropical plant species gave way to deciduous ones, grasses therefore greatly diversified, and herbivorous mammals evolved alongside it, creating the many grazing animals of today such as horses, antelope, and bison. The Neogene traditionally ended at the end of the Pliocene Epoch, just before the definition of the beginning of the Quaternary Period. However, there was a movement amongst geologists to also include ongoing geological time in the Neogene, by dividing the Cenozoic Era into three periods instead of seven epochs, the periods are more closely comparable to the duration of periods in the Mesozoic and Paleozoic eras. The International Commission on Stratigraphy once proposed that the Quaternary be considered a sub-era of the Neogene, with a date of 2.58 Ma. In the 2004 proposal of the ICS, the Neogene would have consisted of the Miocene and Pliocene epochs, thus the Neogene Period ends bounding the succeeding Quaternary Period at 2.58 Mya. Digital Atlas of Neogene Life for the Southeastern United States — by San Jose State University via Web Archive
13.
Taxonomy (biology)
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Taxonomy is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. The exact definition of taxonomy varies from source to source, but the core of the remains, the conception, naming. There is some disagreement as to whether biological nomenclature is considered a part of taxonomy, the broadest meaning of taxonomy is used here. The word taxonomy was introduced in 1813 by Candolle, in his Théorie élémentaire de la botanique, the term alpha taxonomy is primarily used today to refer to the discipline of finding, describing, and naming taxa, particularly species. In earlier literature, the term had a different meaning, referring to morphological taxonomy, ideals can, it may be said, never be completely realized. They have, however, a value of acting as permanent stimulants. Some of us please ourselves by thinking we are now groping in a beta taxonomy, turrill thus explicitly excludes from alpha taxonomy various areas of study that he includes within taxonomy as a whole, such as ecology, physiology, genetics, and cytology. He further excludes phylogenetic reconstruction from alpha taxonomy, thus, Ernst Mayr in 1968 defined beta taxonomy as the classification of ranks higher than species. This activity is what the term denotes, it is also referred to as beta taxonomy. How species should be defined in a group of organisms gives rise to practical and theoretical problems that are referred to as the species problem. The scientific work of deciding how to define species has been called microtaxonomy, by extension, macrotaxonomy is the study of groups at higher taxonomic ranks, from subgenus and above only, than species. While some descriptions of taxonomic history attempt to date taxonomy to ancient civilizations, earlier works were primarily descriptive, and focused on plants that were useful in agriculture or medicine. There are a number of stages in scientific thinking. Early taxonomy was based on criteria, the so-called artificial systems. Later came systems based on a complete consideration of the characteristics of taxa, referred to as natural systems, such as those of de Jussieu, de Candolle and Bentham. The publication of Charles Darwins Origin of Species led to new ways of thinking about classification based on evolutionary relationships and this was the concept of phyletic systems, from 1883 onwards. This approach was typified by those of Eichler and Engler, the advent of molecular genetics and statistical methodology allowed the creation of the modern era of phylogenetic systems based on cladistics, rather than morphology alone. Taxonomy has been called the worlds oldest profession, and naming and classifying our surroundings has likely been taking place as long as mankind has been able to communicate
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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
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Chordate
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Chordates are deuterostomes, as during the embryo development stage the anus forms before the mouth. They are also bilaterally symmetric coelomates, in the case of vertebrate chordates, the notochord is usually replaced by a vertebral column during development, and they may have body plans organized via segmentation. There are also additional extinct taxa, the Vertebrata are sometimes considered as a subgroup of the clade Craniata, consisting of chordates with a skull, the Craniata and Tunicata compose the clade Olfactores. Of the more than 65,000 living species of chordates, the worlds largest and fastest animals, the blue whale and peregrine falcon respectively, are chordates, as are humans. Fossil chordates are known from at least as early as the Cambrian explosion, Hemichordata, which includes the acorn worms, has been presented as a fourth chordate subphylum, but it now is usually treated as a separate phylum. The Hemichordata, along with the Echinodermata, form the Ambulacraria, the Chordata and Ambulacraria form the superphylum Deuterostomia, composed of the deuterostomes. Attempts to work out the relationships of the chordates have produced several hypotheses. All of the earliest chordate fossils have found in the Early Cambrian Chengjiang fauna. Because the fossil record of early chordates is poor, only molecular phylogenetics offers a prospect of dating their emergence. However, the use of molecular phylogenetics for dating evolutionary transitions is controversial and it has also proved difficult to produce a detailed classification within the living chordates. Attempts to produce family trees shows that many of the traditional classes are paraphyletic. While this has been known since the 19th century, an insistence on only monophyletic taxa has resulted in vertebrate classification being in a state of flux. Although the name Chordata is attributed to William Bateson, it was already in prevalent use by 1880, ernst Haeckel described a taxon comprising tunicates, cephalochordates, and vertebrates in 1866. Though he used the German vernacular form, it is allowed under the ICZN code because of its subsequent latinization, among the vertebrate sub-group of chordates the notochord develops into the spine, and in wholly aquatic species this helps the animal to swim by flexing its tail. In fish and other vertebrates, this develops into the spinal cord, the pharynx is the part of the throat immediately behind the mouth. In fish, the slits are modified to form gills, a muscular tail that extends backwards behind the anus. This is a groove in the wall of the pharynx. In filter-feeding species it produces mucus to gather food particles, which helps in transporting food to the esophagus and it also stores iodine, and may be a precursor of the vertebrate thyroid gland
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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
17.
John Latham (ornithologist)
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John Latham was an English physician, naturalist and author. Latham has been called the grandfather of Australian ornithology and his main works were A General Synopsis of Birds and General History of Birds. He was able to examine specimens of Australian birds which reached England in the last twenty years of the 18th century and these included the emu, sulphur-crested cockatoo, wedge-tailed eagle, superb lyrebird and Australian magpie. He was also the first to describe the hyacinth macaw, John Latham was born on 27 June 1740 at Eltham in south east London. He was the eldest son of John Latham, a surgeon there and he was educated at Merchant Taylors School and then studied anatomy under William Hunter and completed his medical education in London hospitals. In 1763 at the age of 23 he began working as a physician in the village of Darenth, in the same year he married Ann Porter. They had four children of whom a son John and a daughter Ann survived childhood, Latham retired from his medical practice aged 56 in 1796 and moved to live near his son at Romsey in Hampshire. His wife died in 1798 and Latham remarried the year to Ann Delamott. His son who had invested in a series of inns became heavily indebted and was declared bankrupt in 1817, Latham lost much of his wealth in supporting his son. In 1819 Latham sold his house in Romsey and moved with his wife to live with his daughters family in Winchester and his second wife died in 1821 and then in the following year his son committed suicide. Latham died aged 96 in Winchester on the 4 February 1837 and was buried in Romsey Abbey, a General Synopsis of Birds was Lathams first ornithological work and contained 106 illustrations by the author. It described many new species which Latham had discovered in various museums, in this work, like Georges-Louis Leclerc, Comte de Buffon, he did not attach importance to the names of the species which he described. Later, Latham realised that only the use of the Linnean binomial system would give him the honour of originating the species scientific names, thus he published in 1790, a Index Ornithologicus where he specified a binomial name for all the species which he had previously described. Nevertheless, there are around eighty bird species for which Lathams 1790 publication is cited as the authority and these include the emu, the black swan, the hyacinth macaw, the sulphur-crested cockatoo, and the noisy friarbird. Working from drawings, Latham appears to have had difficulty in distinguishing the different species and this has caused some confusion in the ornithological literature as to the correct scientific name. Lathams 1801 Latin supplement is the authority for around seventy species of birds and they include the Pacific gull, the barking owl, the noisy miner, the Australian magpie and the magpie-lark. Beginning in 1821, when Latham was in his eighties, he published a version in eleven volumes of his earlier work with the title A General History of Birds. The ornithologist Alfred Newton later wrote that, his defect as a compiler, which had manifest itself before, rather increased with age, Latham maintained a regular correspondence with Thomas Pennant, Joseph Banks, Ashton Lever and others
18.
William Elford Leach
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William Elford Leach, MD, FRS was an English zoologist and marine biologist. Elford Leach was born at Hoe Gate, Plymouth, the son of an attorney, at the age of twelve he began a medical apprenticeship at the Devonshire and Exeter Hospital, studying anatomy and chemistry. By this time he was already collecting marine animals from Plymouth Sound, at seventeen he began studying medicine at St Bartholomews Hospital in London, finishing his training at the University of Edinburgh before graduating MD from the University of St Andrews. Here he threw himself into the task of reorganising and modernising these collections, in 1815, he published the first bibliography of entomology in Brewsters Edinburgh Encyclopedia. He also worked and published on other invertebrates, amphibians, reptiles, mammals, and was the naturalist who separated the centipedes and millipedes from the insects, giving them their own group, the Myriapoda. In his day he was the leading expert on the Crustacea and was in contact with scientists in the United States. In 1816 he was elected a Fellow of the Royal Society at the age of 25, however, in 1821 he suffered a nervous breakdown due to overwork and became unable to continue his researches. He resigned from the museum in March 1822 and his elder sister Jane took him to continental Europe to convalesce and they lived in Italy and Malta and he died from cholera in San Sebastiano Curone, near Tortona, north of Genoa on 25 August 1836. He was one of the most laborious and successful, as well as one of the most universal, in Britain zoologists remained committed to the system of animal classification introduced by Linnaeus in the middle of the 18th century. This was a tool but its principles led to artificial groupings of species when creating larger groups such as genera. For example, Linnaeus had called all animals encased in an outer skeleton. The grouping does separate animals with hard outer skeletons from jellyfish, worms, snails, vertebrates, etc. in continental Europe in the late 18th century naturalists began to revise the way they grouped species. They used an array of characters, not just one or two, and began to discern groups of species that physically resembled one another, lived in similar ways. They created new genera to house these coherent groups and referred to these as natural genera and they named this approach the natural method or natural system of classification. Unlike many of his countrymen, Leach was aware of developments across the English Channel. He read the French literature and, despite the war with France and he applied the new principles to his own research and brought them to the attention of other British zoologists through his publications. Between the years 1813 and 1830 he produced more than 130 scientific articles, by applying the natural method in these works he created more than 380 new genera, many of which have stood the test of time and remain valid today. In 1834, at the meeting of the British Association for the Advancement of Science, Leonard Jenyns reported on The Recent Progress
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Raphinae
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The Raphinae are a clade of extinct flightless birds formerly called didines or didine birds. Historically, many different groups have been named for both the dodo and the Rodrigues solitaire, not all grouping them together, most recently, it is considered that the two birds can be classified in Columbidae, often under the subfamily Raphinae. The first person to suggest an affinity to the doves was Johannes Theodor Reinhardt, whose opinions were then supported by Hugh Edwin Strickland. Recent extractions of DNA from the dodo and Rodrigues solitaire, as well as 37 species of doves, has found where in Columbidae the raphines should be placed, a third raphine, Raphus solitarius, is now considered to be an ibis in the genus Threskiornis. Both the Rodrigues solitaire and the dodo are now extinct, a common threshold of the extinction of the dodo is 1662, but some possible sightings had been made as late as 1688. The last sighting with a description was in 1662, but an analysis by Roberts. The Rodrigues solitaire was killed off later than the dodo, the IUCN uses an extinction date of 1778 for the solitaire, although a more probable date would be in the 1750s or 1760s. Both birds became extinct as a consequence of human hunting and the introduction of mammals that ate the birds and this clade is part of the order Columbiformes and contains the monotypic genera Pezophaps and Raphus. The former contains the species Pezophaps solitaria, the latter the dodo and these birds reached an impressive size as a result of isolation on islands free of predators, in accordance with Fosters rule. Historically, the dodo was assigned the genus Didus, now a synonym of Raphus. In 1848, a new species within the now defunct genus Didus, D. nazarenus, was named by Hugh Edwin Strickland, to house their new species, as well as the other species known at the time, Strickland and Melville named the subfamily Didinae. In 1893 three species were assigned to the group Pezophaps solitarius, Didus ineptus, and the possible species Didus borbonicus, today, only two raphine species are known, with Didus ineptus becoming a junior subjective synonym of Raphus cucullatus, Didus. Borbonicus now classified as the ibis Threskiornis solitarius, and Didus nazarenus being identified as synonymous with Pezophaps solitarius. A suborder named in 1893 by Sharpe, Didi was defined as a group including only the birds, that were sister to Columbidae, from the Mascarene Islands of Mauritius, Réunion. Features grouping Didi with Columbidae were the angle of the mandible, in 1811, Johann Karl Wilhelm Illiger created a new family for the genus Didus. He named the family Inepti, and in it included only Didus ineptus, Illiger concluded that the dodo was related to ostriches and rheas, and so placed Inepti in the order Rasores, as the sister family to Gallinacei, Epollicati, Columbini, and Crypturi. In 1842, Johannes Theodor Reinhardt proposed they were ground doves, Strickland stated that although not identical, these birds shared many distinguishing features in the leg bones, features which were otherwise known only in pigeons. The raphines are sometimes separated as a distinct family Raphidae, and they were initially placed in the ratites due to their peculiar, flightlessness-related apomorphies, and a relationship to the Rallidae has also been suggested
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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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Species
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In biology, a species is the basic unit of biological classification and a taxonomic rank. A species is defined as the largest group of organisms in which two individuals can produce fertile offspring, typically by sexual reproduction. While this definition is often adequate, looked at more closely it is problematic, for example, with hybridisation, in a species complex of hundreds of similar microspecies, or in a ring species, the boundaries between closely related species become unclear. Other ways of defining species include similarity of DNA, morphology, all species are given a two-part name, a binomial. The first part of a binomial is the genus to which the species belongs, the second part is called the specific name or the specific epithet. For example, Boa constrictor is one of four species of the Boa genus, Species were seen from the time of Aristotle until the 18th century as fixed kinds that could be arranged in a hierarchy, the great chain of being. In the 19th century, biologists grasped that species could evolve given sufficient time, Charles Darwins 1859 book The Origin of Species explained how species could arise by natural selection. Genes can sometimes be exchanged between species by horizontal transfer, and species may become extinct for a variety of reasons. In his biology, Aristotle used the term γένος to mean a kind, such as a bird or fish, a kind was distinguished by its attributes, for instance, a bird has feathers, a beak, wings, a hard-shelled egg, and warm blood. A form was distinguished by being shared by all its members, Aristotle believed all kinds and forms to be distinct and unchanging. His approach remained influential until the Renaissance, when observers in the Early Modern period began to develop systems of organization for living things, they placed each kind of animal or plant into a context. Many of these early delineation schemes would now be considered whimsical, animals likewise that differ specifically preserve their distinct species permanently, one species never springs from the seed of another nor vice versa. In the 18th century, the Swedish scientist Carl Linnaeus classified organisms according to shared physical characteristics and he established the idea of a taxonomic hierarchy of classification based upon observable characteristics and intended to reflect natural relationships. At the time, however, it was widely believed that there was no organic connection between species, no matter how similar they appeared. However, whether or not it was supposed to be fixed, by the 19th century, naturalists understood that species could change form over time, and that the history of the planet provided enough time for major changes. Jean-Baptiste Lamarck, in his 1809 Zoological Philosophy, described the transmutation of species, proposing that a species could change over time, in 1859, Charles Darwin and Alfred Russel Wallace provided a compelling account of evolution and the formation of new species. Darwin argued that it was populations that evolved, not individuals and this required a new definition of species. Darwin concluded that species are what appear to be, ideas
22.
Indomalayan realm
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The Indomalayan realm is one of the eight biogeographic realms. It extends across most of South and Southeast Asia and into the parts of East Asia. Indomalaya also includes the Philippines, lowland Taiwan, and Japans Ryukyu Islands, the tropical moist forests of Indomalaya are mostly dominated by trees of the dipterocarp family. The Indian Subcontinent bioregion covers most of India, Bangladesh, Nepal, Bhutan, the Hindu Kush, Karakoram, and Himalaya are a major biogeographic boundary between the subtropical and tropical flora and fauna of the Indian subcontinent and the temperate-climate Palearctic realm. The Indochina bioregion includes most of mainland Southeast Asia, including Myanmar, Thailand, Laos, Vietnam, malesia is a botanical province which straddles the boundary between Indomalaya and Australasia. It includes the Malay Peninsula and the western Indonesian islands, the Philippines, the eastern Indonesian islands, the flora of Indomalaya blends elements from the ancient supercontinents of Laurasia and Gondwana. India collided with Asia 30-45 MYA, and exchanged species, two orders of mammals, the colugos and treeshrews, are endemic to the realm, as are families Craseonycteridae, Diatomyidae, Platacanthomyidae, Tarsiidae and Hylobatidae. Large mammals characteristic of Indomalaya include the leopard, tigers, water buffalos, Asian Elephant, Indian Rhinoceros, Javan Rhinoceros, Malayan Tapir, orangutans, Indomalaya has three endemic bird families, the Irenidae, Megalaimidae and Rhabdornithidae. Also characteristic are pheasants, pittas, Old World babblers, more information is available under Indomalayan realm fauna. Malesia Sundaland Ecoregions of India Ecoregions of the Philippines Map of the Indomalaya ecozone. Wikramanayake, E. E. Dinerstein, C. J. Loucks, D. M. Olson, J. Morrison, J. L. Lamoreux, M. McKnight, terrestrial ecoregions of the Indo-Pacific, a conservation assessment
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Australasian realm
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The Australasian realm is an biogeographic realm that is coincident, but not synonymous, with the geographical region of Australasia. The Australasian realm also includes several Pacific island groups, including the Bismarck Archipelago, Vanuatu, the Solomon Islands, New Zealand and its surrounding islands are a distinctive sub-region of the Australasian realm. The rest of Indonesia is part of the Indomalayan realm, from an ecological perspective the Australasian realm is a distinct region with a common geologic and evolutionary history and a great many unique plants and animals. In this context, Australasia is limited to Australia, New Guinea, New Zealand, New Caledonia, the biological dividing line from the Indomalayan realm of tropical Asia is the Wallace Line, Borneo and Bali lie on the western, Asian side. These three land masses have been separated from other continents, and from one another, for millions of years. All of Australasia shares the Antarctic flora, although the northern, Australia, New Guinea, and Tasmania are separated from one another by shallow continental shelves, and were linked together when the sea level was lower during ice ages. They share a similar fauna which includes marsupial and monotreme mammals, eucalypts are the predominant trees in much of Australia and New Guinea. New Zealand has no land mammals, but also had ratite birds, including the kiwi. Note that this zonation is based on flora, animals do not necessarily follow the same biogeographic boundaries, in the present case, many birds occur in both Indomalayan and Australasian regions, but not across the whole of either. On the other hand, there are few faunistic commonalities shared only by Australia and New Zealand, meanwhile, Australia, Melanesia and the Wallacea are united by a large share of similar animals, but few of these occur farther into the Pacific. On the other hand, much of the Polynesian fauna is related to that of Melanesia, Australasia Oceania Panda. org, Map of the Ecozones
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Biogeographic realm
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A biogeographic realm or ecozone is the broadest biogeographic division of the Earths land surface, based on distributional patterns of terrestrial organisms. They are subdivided in ecoregions, which are classified in biomes or habitat types, as such, biogeographic realms designations are used to indicate general groupings of organisms based on their shared biogeography. Biogeographic realms correspond to the kingdoms of botany or zoogeographic regions of zoology. Biogeographic realms are characterized by the history of the organisms they contain. Biomes are characterized by similar climax vegetation, each realm may include a number of different biomes. The biogeographic realms of Udvardy were defined based on taxonomic composition, the rank corresponds more or less to the floristic kingdoms and zoogeographic regions. The usage of the ecozone is more variable. It was used originally in stratigraphy, in Canadian literature, the term was used by Wiken in macro level land classification, with geographic criteria. Later, Schültz would use it with ecological and physiognomical criteria, in the Global 200/WWF scheme, originally the term biogeographic realm in Udvardy sense was used. However, in a scheme of BBC, it was replaced by the term ecozone, in the WWF system, The Australasia realm includes Australia, Tasmania, the islands of Wallacea, New Guinea, the East Melanesian islands, New Caledonia, and New Zealand. The Palearctic and Nearctic are sometimes grouped into the Holarctic realm, the drainage basins of the principal oceans and seas of the world are marked by continental divides. The grey areas are endorheic basins that do not drain to the ocean
25.
Rock dove
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The rock dove or rock pigeon is a member of the bird family Columbidae. In common usage, this bird is often referred to as the pigeon. The species includes the domestic pigeon, including the fancy pigeon, escaped domestic pigeons have raised the populations of feral pigeons around the world. Wild rock doves are pale grey with two bars on each wing, while domestic and feral pigeons are very variable in colour. There are few differences between males and females. The species is monogamous, with two squabs per brood. Both parents care for the young for a time, habitats include various open and semi-open environments. Cliffs and rock ledges are used for roosting and breeding in the wild, originally found wild in Europe, North Africa, and western Asia, pigeons have become established in cities around the world. The species is abundant, with a population of 17 to 28 million feral. The rock dove was first described by Gmelin in 1789, the genus name Columba is the Latin word meaning pigeon, dove, whose older etymology comes from the Ancient Greek κόλυμβος, a diver, from κολυμβάω, dive, plunge headlong, swim. Aristophanes and others use the word κολυμβίς, diver, for the name of the bird, the specific epithet is derived from the Latin livor, bluish. Its closest relative in the Columba genus is the pigeon, followed by the other rock pigeons. In common usage, this bird is often simply referred to as the pigeon. There are 12 subspecies recognised by Gibbs, some of these may be derived from feral stock. C. l. livia, the subspecies, occurs in western and southern Europe, northern Africa, and Asia to western Kazakhstan, the northern Caucasus, Georgia, Cyprus, Turkey, Iran. C. l. atlantis of Madeira, the Azores and Cape Verde, is a very variable population with chequered upperparts obscuring the black wingbars, C. l. canariensis of the Canary Islands, is smaller and averages darker than the nominate subspecies. C. l. gymnocyclus from Senegal and Guinea to Ghana, Benin and Nigeria is smaller and it is almost blackish on the head, rump and underparts with a white back and the iridescence of the nape extending onto the head. C. l. targia breeds in the mountains of the Sahara east to Sudan and it is slightly smaller than the nominate form, with similar plumage, but the back is concolorous with the mantle instead of white
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Domestic pigeon
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The domestic pigeon is a pigeon that was derived from the rock pigeon. The rock pigeon is the worlds oldest domesticated bird, mesopotamian cuneiform tablets mention the domestication of pigeons more than 5,000 years ago, as do Egyptian hieroglyphics. Research suggests that domestication of pigeons occurred as early as 10,000 years ago, pigeons have made contributions of considerable importance to humanity, especially in times of war. In war the homing ability of pigeons has been put to use by making them messengers, so-called war pigeons have carried many vital messages and some have been decorated for their services. Medals such as the Croix de guerre, awarded to Cher Ami, joe and Paddy, amongst 32 others, have been awarded to pigeons for their services in saving human lives. Domestic pigeons reproduce in a way to the wild rock pigeon. Generally humans will select breeding partners, crop milk produced by parent birds may occasionally be replaced with artificial substitutes. Baby pigeons are called squeakers or squabs, trained domestic pigeons are able to return to the home loft if released at a location that they have never visited before and that may be up to 1000 km away. The ability a pigeon has to return home from a strange location necessitates two sorts of information, the first, called map sense is their geographic location. The second, compass sense is the bearing they need to fly from their new location in order to reach their home, both of these senses, however, respond to a number of different cues in different situations. The most popular conception of how pigeons are able to do this is that they are able to sense the Earths magnetic field with tiny magnetic tissues in their head. This is all the more surprising as they are not a migratory species, another theory is that pigeons have compass sense, which uses the position of the sun, along with an internal clock, to work out direction. However, studies have shown that if magnetic disruption or clock changes disrupt these senses, pigeons grow to a very large size in the nest before they are fledged and able to fly, and in this stage of their development they are prized as food. For commercial meat production a breed of large pigeon, named King pigeon, has been developed by selective breeding. Breeds of pigeons developed for their meat are known as utility pigeons. Pigeon fanciers developed many forms of pigeon. These are generally classed as fancy pigeons, fanciers compete against each other at exhibitions or shows and the different forms or breeds are judged to a standard to decide who has the best bird. Among those breeds are the English carrier pigeons, a variety of pigeon with wattles, there are many ornamental breeds of pigeons, including the Duchess breed, which has as a prominent characteristic feet that are completely covered by a sort of fan of feathers
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Feral pigeon
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Feral pigeons, also called city doves, city pigeons, or street pigeons, are pigeons that are derived from the domestic pigeons that have returned to the wild. The domestic pigeon was originally bred from the rock dove. Rock, domestic, and feral pigeons are all the same species, Feral pigeons find the ledges of buildings to be a substitute for sea cliffs, have become adapted to urban life, and are abundant in towns and cities throughout much of the world. Current evidence suggests that wild, domestic and feral pigeons mate for life and they are socially monogamous, but extra-pair matings do occur, often initiated by males. Due to their ability to produce milk, pigeons can breed at any time of year. Courtship rituals can be observed in urban parks at any time of the year, the male on the ground or rooftops puffs up the feathers on his neck to appear larger and thereby impress or attract attention. He approaches the hen at a walking pace while emitting repetitive quiet notes. At first, the female invariably walks or flies a short distance away, at this point, he continues the bowing motion and very often makes full- or half-pirouettes in front of the female. The male then proceeds to feed the female by regurgitating food, the male then mounts the female, rearing backwards to be able to join their cloacae. The mating is very brief with the male flapping his wings to balance on top of the female. Abandoned buildings are favourite nesting areas, mass nesting is common as pigeons are a community flocking bird, often, dozens of birds share a building. Loose tiles and broken windows provide access, and pigeons are adept at spotting new access points, nests and droppings tend to stay clustered and remain dry when out of the weather. Pigeons are particularly fond of roof spaces, any water tank or cistern on a roof must, therefore, be secured and sealed off to keep the pigeons out of them. The popularity of an area does not seem to be affected by the pigeons population density. On undamaged property, the gutters, window air conditioners and empty air conditioner containers, chimney pots, many building owners try to limit roosting by using bird control spikes and netting to cover ledges and potential nesting places on buildings. This has little effect on the size of the pigeon population, in the UK, only the larger and more wary common wood pigeon, which often shares the same territory and food supply, builds nests in trees, usually close to roads. In Wendell Levis The Pigeon, he describes the crowing/cooing of pigeons as mostly being associated with strutting and fighting in male birds, hens also coo, but this is noticeably less guttural than the cooing of the cock. Cooing is also more frequent between couples during mating and nesting, both parents participate in the incubation of the eggs
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Dialect
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That happens, for example, across large parts of India or the Maghreb. Historically, it happened in various parts of Europe such as between Portugal, southern Belgium and southern Italy, and between Flanders and Austria. Leonard Bloomfield used the dialect area. It is analogous to a species in evolutionary biology. Dialect continua typically occur in long-settled agrarian populations, as innovations spread from their various points of origin as waves, in this situation, hierarchical classifications of varieties are impractical. Instead, dialectologists map variation of language features across a dialect continuum. The influential Atlas linguistique de la France pioneered the use of a trained fieldworker and these atlases typically consist of display maps, each showing local forms of a particular item at the survey locations. Secondary studies may include maps, showing the areal distribution of various variants. A common tool in these maps is an isogloss, a line separating areas where different variants of a particular feature predominate, in a dialect continuum, isoglosses for different features are typically spread out, reflecting the gradual transition between varieties. A bundle of coinciding isoglosses indicate a stronger dialect boundary, as might occur at geographical obstacles or long-standing political boundaries, in other cases, intersecting isoglosses and more complex patterns are found. Standard varieties may be developed and codified from one or more locations in a continuum, in such cases the local variety is said to be dependent on, or heteronomous with respect to, the standard variety. The Scandinavian languages, Danish, Norwegian and Swedish, are cited as examples. Conversely, a defined in this way may include local varieties that are mutually unintelligible. The choice of standard is determined by a political boundary. As a results, speakers on either side of the boundary may use almost identical varieties, but treat them as dependent on different standards, the choice may be a matter of national, regional or religious identity, and may be controversial. In the Yugoslav republic of Macedonia, a standard was developed from local varieties within a continuum with Serbia to the north, the standard was deliberately based on varieties from the west of the republic that were most different from standard Bulgarian. Now known as Macedonian, it is the standard of the independent Republic of Macedonia. Europe provides several examples of dialect continua, the largest of which involve the Germanic, Romance and Slavic branches of the Indo-European language family
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Crop milk
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Crop milk is a secretion from the lining of the crop of parent birds that is regurgitated to young birds. It is found among all pigeons and doves where it is referred to as pigeon milk, an analog to crop milk is also secreted from the esophagus of flamingos and some penguins. Crop milk bears little resemblance to mammalian milk, the former being a semi-solid substance somewhat like pale yellow cottage cheese. It is extremely high in protein and fat, containing higher levels than cow or human milk and it has also been shown to contain anti-oxidants and immune-enhancing factors. Like mammalian milk, crop milk contains IgA antibodies, unlike mammalian milk, which is an emulsion, pigeon crop milk consists of a suspension of protein-rich and fat-rich cells that proliferate and detach from the lining of the crop. In pigeons and flamingoes, both the male and female adult produce crop milk and share in the feeding and care of the young, in penguins, only the males lactate. Lactation in birds is also controlled by prolactin, which is the hormone that causes lactation in mammals. Pigeons milk begins to be produced a couple of days before the eggs are due to hatch. The parents may cease to eat at this point in order to be able to provide the squabs with milk uncontaminated by seeds, the baby squabs are fed on pure crop milk for the first week or so of life. If one egg fails to hatch, the surviving squab gets the advantage of a supply of crop milk sufficient for two squabs and grows at a faster rate. Research suggests that a pair of breeding pigeons cannot produce enough milk to adequately feed three squabs, which explains why clutches are limited to two. The very high nutrient concentration of pigeons milk makes it difficult to devise an artificial substitute for hand-rearing squabs, a good home-made mix can be made from equal quantities of dehydrated dried pure soy protein and soy-based dairy-free butter-substitute. This is made into a paste with a little water, a tiny crumb of a multivitamin tablet. The crop should be allowed to empty completely between feedings, with care and gentleness, it is possible to raise a pigeon on this mix from the moment of hatching. Soy based infant formula can be used as a substitute when other options are not available, the content of vitamins and minerals is very similar to crop milk. Soy based formula, nutritional value-> The soy based formula must not contain lactose because birds can not digest it, the infant formula mix is used in the same way as Nutribird A21, depending on age of the bird. Overfilling the crop may lead to fermentation and souring of the crop milk substitute, the crop should still feel *squishy* after a feed, not like a full water balloon or hard like a ball. If the content has once turned to fermentation, the needs to be emptied by a vet or experienced carer to avoid death
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Crop (anatomy)
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A crop is a thin-walled expanded portion of the alimentary tract used for the storage of food prior to digestion. This anatomical structure is found in a variety of animals. It has been found in birds, some non-avian dinosaurs, and in animals including gastropods, earthworms, leeches. Cropping is used by bees to store nectar of flowers. When bees suck nectar, it is stored in their crops, in a birds digestive system, the crop is an expanded, muscular pouch near the gullet or throat. It is a part of the tract, essentially an enlarged part of the esophagus. As with most other organisms that have a crop, the crop is used to store food. Not all birds have a crop, in adult doves and pigeons, the crop can produce crop milk to feed newly hatched birds. Scavenging birds, such as vultures, will gorge themselves when prey is abundant and they subsequently sit, sleepy or half torpid, to digest their food. Most raptors, including hawks, eagles and vultures, have a crop, however, similarly, all true quail have a crop, but the buttonquail or Turnicidae do not. While chickens and turkeys possess a crop, geese do not have one, the fact that geese do not have crops occasioned what many consider to be the great fictional detective Sherlock Holmes—or rather author Arthur Conan Doyles—biggest forensic blunder. In The Adventure of the Blue Carbuncle, a valuable gem is supposedly hidden in a gooses crop. Esophagus Gizzard Gular pouch, in bird anatomy, a generally used to store fish
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Family (biology)
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In biological classification, family is one of the eight major taxonomic ranks, it is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks above the rank of genus. In vernacular usage, a family may be named one of its common members, for example, walnuts and hickory trees belong to the family Juglandaceae. What does or does not belong to a family—or whether a family should be recognized at all—are proposed and determined by practicing taxonomists. There are no rules for describing or recognizing a family. Taxonomists often take different positions about descriptions of taxa, and there may be no broad consensus across the community for some time. Some described taxa are accepted broadly and quickly, but others only rarely, if at all, the naming of families is codified by various international codes. In zoological nomenclature, the names of animals end with the suffix -idae. The concept of rank at time was not yet settled, and in the preface to the Prodromus Magnol spoke of uniting his families into larger genera. Carolus Linnaeus used the word familia in his Philosophia botanica to denote groups of plants, trees, herbs, ferns, palms. He used this term only in the section of the book. In zoology, the family as an intermediate between order and genus was introduced by Pierre André Latreille in his Précis des caractères génériques des insectes. He used families in some but not in all his orders of insects, families can be used for evolutionary, palaeontological and generic studies because they are more stable than lower taxonomic levels such as genera and species
32.
British Museum
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The British Museum is dedicated to human history, art and culture, and is located in the Bloomsbury area of London. The British Museum was established in 1753, largely based on the collections of the physician, the museum first opened to the public on 15 January 1759, in Montagu House, on the site of the current building. Although today principally a museum of art objects and antiquities. Its foundations lie in the will of the Irish-born British physician, on 7 June 1753, King George II gave his formal assent to the Act of Parliament which established the British Museum. They were joined in 1757 by the Old Royal Library, now the Royal manuscripts, together these four foundation collections included many of the most treasured books now in the British Library including the Lindisfarne Gospels and the sole surviving copy of Beowulf. The British Museum was the first of a new kind of museum – national, belonging to neither church nor king, freely open to the public, sloanes collection, while including a vast miscellany of objects, tended to reflect his scientific interests. The addition of the Cotton and Harley manuscripts introduced a literary, the body of trustees decided on a converted 17th-century mansion, Montagu House, as a location for the museum, which it bought from the Montagu family for £20,000. The Trustees rejected Buckingham House, on the now occupied by Buckingham Palace, on the grounds of cost. With the acquisition of Montagu House the first exhibition galleries and reading room for scholars opened on 15 January 1759. During the few years after its foundation the British Museum received several gifts, including the Thomason Collection of Civil War Tracts. A list of donations to the Museum, dated 31 January 1784, in the early 19th century the foundations for the extensive collection of sculpture began to be laid and Greek, Roman and Egyptian artefacts dominated the antiquities displays. Gifts and purchases from Henry Salt, British consul general in Egypt, beginning with the Colossal bust of Ramesses II in 1818, many Greek sculptures followed, notably the first purpose-built exhibition space, the Charles Towneley collection, much of it Roman Sculpture, in 1805. In 1816 these masterpieces of art, were acquired by The British Museum by Act of Parliament. The collections were supplemented by the Bassae frieze from Phigaleia, Greece in 1815, the Ancient Near Eastern collection also had its beginnings in 1825 with the purchase of Assyrian and Babylonian antiquities from the widow of Claudius James Rich. The neoclassical architect, Sir Robert Smirke, was asked to draw up plans for an extension to the Museum. For the reception of the Royal Library, and a Picture Gallery over it, and put forward plans for todays quadrangular building, much of which can be seen today. The dilapidated Old Montagu House was demolished and work on the Kings Library Gallery began in 1823, the extension, the East Wing, was completed by 1831. The Museum became a site as Sir Robert Smirkes grand neo-classical building gradually arose
33.
Sandgrouse
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Sandgrouse is the common name for Pteroclididae, a family of sixteen species of bird, members of the order Pteroclidiformes. They are traditionally placed in two genera, the two central Asian species are classified as Syrrhaptes and the other fourteen species, from Africa and Asia, are placed in the genus Pterocles. They are ground dwelling birds restricted to treeless, open country, such as plains, savannahs and they are distributed across northern, southern and eastern Africa, Madagascar, the Middle East and India through to central Asia. Sandgrouse have small, pigeon-like heads and necks and sturdy compact bodies and they range in size from 24 to 40 centimetres in length and from 150 to 500 grams in weight. The adults are sexually dimorphic with the males being slightly larger and they have eleven strong primary feathers and long pointed wings giving them a fast direct flight. The muscles of the wings are powerful and the birds are capable of take off. In some species, the feathers in the tail are extended into long points. The plumage is cryptic, generally being in shades of brown, grey and buff, variously mottled and barred. There is a layer of under down which helps insulate the bird from extremes of heat. The feathers of the belly are specially adapted for absorbing water and retaining it, allowing adults, particularly males, the amount of water that can be carried in this way is 15 to 20 millilitres. Members of the genus Syrrhaptes are found in the steppes of central Asia and their range extends from the Caspian Sea through southern Siberia, Tibet and Mongolia to northern and central China. They are normally resident, but Pallass sandgrouse can be locally migratory and very occasionally is irruptive, appearing in areas well outside its normal range. This happened in 1863 and 1888, and a major irruption took place in 1908 when many birds were seen as far afield as Ireland and the United Kingdom where they bred in Yorkshire and Moray. Members of the genus Pterocles are mainly found in the parts of northern, eastern and southern Africa though the range of some species extends into the Middle East. The Madagascar sandgrouse is restricted to Madagascar, the black-bellied sandgrouse and the pin-tailed sandgrouse also occur in Spain, Portugal and southern France. Most species are sedentary though some make local migrations, typically to lower altitudes in winter, other food items eaten include green shoots and leaves, bulbs and berries. Insect food such as ants and termites may be eaten especially during the breeding season, the diet of many sandgrouse is highly specialised, with the seeds of a small number of plant species being dominant. This may depend on local availability but in cases it reflects actual selection of favoured seeds over others by the sandgrouse
34.
Pteroclidiformes
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Sandgrouse is the common name for Pteroclididae, a family of sixteen species of bird, members of the order Pteroclidiformes. They are traditionally placed in two genera, the two central Asian species are classified as Syrrhaptes and the other fourteen species, from Africa and Asia, are placed in the genus Pterocles. They are ground dwelling birds restricted to treeless, open country, such as plains, savannahs and they are distributed across northern, southern and eastern Africa, Madagascar, the Middle East and India through to central Asia. Sandgrouse have small, pigeon-like heads and necks and sturdy compact bodies and they range in size from 24 to 40 centimetres in length and from 150 to 500 grams in weight. The adults are sexually dimorphic with the males being slightly larger and they have eleven strong primary feathers and long pointed wings giving them a fast direct flight. The muscles of the wings are powerful and the birds are capable of take off. In some species, the feathers in the tail are extended into long points. The plumage is cryptic, generally being in shades of brown, grey and buff, variously mottled and barred. There is a layer of under down which helps insulate the bird from extremes of heat. The feathers of the belly are specially adapted for absorbing water and retaining it, allowing adults, particularly males, the amount of water that can be carried in this way is 15 to 20 millilitres. Members of the genus Syrrhaptes are found in the steppes of central Asia and their range extends from the Caspian Sea through southern Siberia, Tibet and Mongolia to northern and central China. They are normally resident, but Pallass sandgrouse can be locally migratory and very occasionally is irruptive, appearing in areas well outside its normal range. This happened in 1863 and 1888, and a major irruption took place in 1908 when many birds were seen as far afield as Ireland and the United Kingdom where they bred in Yorkshire and Moray. Members of the genus Pterocles are mainly found in the parts of northern, eastern and southern Africa though the range of some species extends into the Middle East. The Madagascar sandgrouse is restricted to Madagascar, the black-bellied sandgrouse and the pin-tailed sandgrouse also occur in Spain, Portugal and southern France. Most species are sedentary though some make local migrations, typically to lower altitudes in winter, other food items eaten include green shoots and leaves, bulbs and berries. Insect food such as ants and termites may be eaten especially during the breeding season, the diet of many sandgrouse is highly specialised, with the seeds of a small number of plant species being dominant. This may depend on local availability but in cases it reflects actual selection of favoured seeds over others by the sandgrouse
35.
Mesite
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The mesites are a family of birds that are part of a clade that include Columbiformes and Pterocliformes. They are smallish, near flightless birds endemic to Madagascar and they are the only family with more than two species in which every species is threatened. There are two genera, Mesitornis and Monias, while the latter is certainly incorrect, there is some indication that they might indeed be closer to the Columbiformes. The purported gruiforms kagu and sunbittern might also be not-too-distant relatives, still, the data hinting at a possible relationship between the odd gruiforms is by no means robust enough to draw a firm conclusion. Arguably, they might be considered an order of their own as has on occasion been done in the past, other researchers have been unable to confirm the Metaves. Recent phylogenomic studies support the grouping of mesites, sandgrouse and pigeons forming the sister taxon to Mirandornithes, the mesites are forest and scrubland birds that feed on insects and seeds. The brown and white-breasted mesites forage on the ground, gleaning insects from the leaves and under them, the subdesert mesite uses its long bill to probe in the soil. Other birds, such as drongos and flycatchers, will follow mesites to catch any insects they flush, mesites are vocal birds, with calls similar to passerine song, used for territorial defence. Two or three eggs are laid in a stick-nest located in a bush or low branch. The Mesitornis species are monogamous, Monias benschi is polygamous and unlike the two shows significant sexual dichromatism
36.
Mirandornithes
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Mirandornithes is a clade that consists of flamingos and grebes. Many scholars use the term Phoenicopterimorphae for the superorder containing flamingoes and grebes, determining the relationships of both groups has been problematic. Flamingos had been placed with numerous branches within Neognathae, such as ducks and storks, the grebes had been placed with the loons. However recent studies have confirmed these two branches as sister groups, both primitive phoenicopteriformes and their closest relatives, the grebes, were highly aquatic. This indicates that the entire group evolved from aquatic, probably swimming ancestors. Humerus with an oval depression at insertion site of musculus scapulohumeralis cranialis. At least four thoracic vertebrae fused to a notarium, distal end of ulna with marked oval depression radialis. Phalanx proximalis digiti majoris very elongate and narrow craniocaudally, distal rim of condylus medialis of tibiotarsus distinctly notched. Pars acetabularis of musculus iliotibialis lateralis absent, pars caudalis of musculus caudofemoralis absent. Wing with 12 primaries Left arteria carotis reduced or absent, eggs covered with a chalky layer of amorphous calcium phosphate
37.
Quail-dove
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Geotrygon is a bird genus in the pigeon and dove family. Its members are called quail-doves and all live in the Neotropics, the 11 species of this genus have ranges from southern Mexico and Central America to the West Indies and South America. Quail-doves are ground-dwelling birds that live, nest, and feed in dense forests and they are remarkable for their purple to brown coloration with light-and-dark facial markings. The species Starnoenas cyanocephala was previously referred to as a quail-dove, gibbs, David, Barnes, Eustace, Cox, John. Pigeons and Doves, A Guide to the Pigeons and Doves of the World
38.
Nucleic acid sequence
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A nucleic acid sequence is a succession of letters that indicate the order of nucleotides within a DNA or RNA molecule. By convention, sequences are presented from the 5 end to the 3 end. For DNA, the strand is used. Because nucleic acids are linear polymers, specifying the sequence is equivalent to defining the covalent structure of the entire molecule. For this reason, the nucleic acid sequence is also termed the primary structure, the sequence has capacity to represent information. Biological deoxyribonucleic acid represents the information which directs the functions of a living thing, nucleic acids also have a secondary structure and tertiary structure. Primary structure is sometimes referred to as primary sequence. Conversely, there is no concept of secondary or tertiary sequence. Nucleic acids consist of a chain of linked units called nucleotides, each nucleotide consists of three subunits, a phosphate group and a sugar make up the backbone of the nucleic acid strand, and attached to the sugar is one of a set of nucleobases. The nucleobases are important in base pairing of strands to form secondary and tertiary structure such as the famed double helix. The possible letters are A, C, G, and T, in the typical case, the sequences are printed abutting one another without gaps, as in the sequence AAAGTCTGAC, read left to right in the 5 to 3 direction. With regards to transcription, a sequence is on the strand if it has the same order as the transcribed RNA. One sequence can be complementary to sequence, meaning that they have the base on each position in the complementary. For example, the sequence to TTAC is GTAA. If one strand of the double-stranded DNA is considered the sense strand, then the other strand, considered the antisense strand, will have the complementary sequence to the sense strand. Apart from adenine, cytosine, guanine, thymine and uracil, in DNA, the most common modified base is 5-methylcytidine. In RNA, there are many modified bases, including pseudouridine, dihydrouridine, inosine, ribothymidine and 7-methylguanosine, hypoxanthine and xanthine are two of the many bases created through mutagen presence, both of them through deamination. Hypoxanthine is produced from adenine, xanthine from guanine, similarly, deamination of cytosine results in uracil
39.
Long branch attraction
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In phylogenetics, long branch attraction is a form of systematic error whereby distantly related lineages are incorrectly inferred to be closely related. Such bias is more common when the overall divergence of some results in long branches within a phylogeny. Long-branches are often attracted to the base of a phylogenetic tree, the frequency of true LBA is unclear and often debated. Although often viewed as a failing of parsimony-based methodology, LBA can result from a variety of scenarios, often this is because convergent evolution of one or more characters included in the analysis has occurred in multiple taxa. Although they were derived independently, these traits can be misinterpreted in the analysis as being shared due to common ancestry. A phylogenetic analysis will group these together as a clade unless other synapomorphies outweigh the homoplastic features to group together true sister taxa. The result of LBA in evolutionary analyses is that rapidly evolving lineages may be inferred to be closely related, for example, in DNA sequence-based analyses, the problem arises when sequences from two lineages evolve rapidly. There are only four possible nucleotides and when DNA substitution rates are high, when this happens, parsimony may erroneously interpret this homoplasy as a synapomorphy. The opposite effect may also be observed, in that if two branches exhibit particularly slow evolution among a wider, fast evolving group, those branches may be misinterpreted as closely related, as such, long branch attraction can in some ways be better expressed as branch length attraction. However, it is typically long branches that exhibit attraction, the recognition of long-branch attraction implies that there is some other evidence that suggests that the phylogeny is incorrect. For example, morphological data may suggest that taxa marked as closely related are not truly sister taxa, hennigs Auxiliary Principle suggests that synapomorphies should be viewed as de facto evidence of grouping unless there is specific contrary evidence. A simple and effective method for determining whether or not long branch attraction is affecting tree topology is the SAW method, named for Siddal, if long branch attraction is suspected in a pair of taxa, simply remove taxon A and re-run the analysis. Then remove A and replace B, running the analysis again, if either of the taxa appear at different branch points in the absence of the other, there is evidence of long branch attraction. Since long branches cant possibly attract one another when one is in the analysis. Assume for simplicity that we are considering a single binary character, because the distance from B to D is small, in the vast majority of all cases, B and D will be the same. Here, we assume that they are both +. If this is the case, there are four remaining possibilities, a and C can both be +, in which case all taxa are the same and all the trees have the same length. A can be + and C can be -, in which only one character is different
40.
Australasia
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Australasia, a region of Oceania, comprises Australia, New Zealand, the island of New Guinea, and neighbouring islands in the Pacific Ocean. Charles de Brosses coined the term in Histoire des navigations aux terres australes and he derived it from the Latin for south of Asia and differentiated the area from Polynesia and the southeast Pacific. The bulk of Australasia sits on the Indo-Australian Plate, together with India, physiographically, Australasia includes New Zealand, Australia, and Melanesia, New Guinea and neighbouring islands north and east of Australia in the Pacific Ocean. The designation is applied to all the lands and islands of the Pacific Ocean lying between the equator and latitude 47° south. Most of Australasia lies on the portion of the Indo-Australian Plate, flanked by the Indian Ocean to the west. Sometimes the term encompasses the island of New Guinea. Many organisations whose names include the prefix Australasian Society of, limit their scope of operation to just Australia and New Zealand. In the past, Australasia has been used as a name for combined Australia/New Zealand sporting teams, examples include tennis between 1905 and 1915, when New Zealand and Australia combined to compete in the Davis Cup international tournament, and at the Olympic Games of 1908 and 1912. From an ecological perspective the Australasia ecozone forms a region with a common geologic and evolutionary history. In this context, Australasia is limited to Australia, New Guinea, New Zealand, New Caledonia, the Wallace Line marks the biological divide from the Indomalaya ecozone of tropical Asia – Borneo and Bali lie on the western, Asian side. These three land masses have been separated from other continents, and from one another, for millions of years, all of Australasia shares the Antarctic flora, although the northern, tropical islands also share many plants with Southeast Asia. Mainland Australia, New Guinea and Tasmania are separated from one another by shallow continental shelves and they share a similar fauna which includes marsupial and monotreme mammals and ratite birds. Eucalypts are the predominant trees in much of Australia and New Guinea, New Zealand has no extant native land mammals aside from bats, but also had ratite birds, including the kiwi and the extinct moa. Media related to Australasia at Wikimedia Commons
41.
Pheasant pigeon
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The pheasant pigeon is a genus of large terrestrial pigeon found in the primary rainforests of New Guinea and nearby islands. It ranges primarily over hilly and lower areas, but can also be found in lowlands. There are four species, which differ primarily in the presence or absence of a small crest, the two best known are the western nominate with a greenish nape and O. aruensis from the Aru Islands with a white nape. The two remaining species, O. cervicalis from the part of its range and O. insularis from Fergusson Island, have a grey nape. The pheasant pigeon is a pigeon of uncertain affinities within the Columbidae, within the genus Otidiphaps. Its scientific name makes reference to its similarities to the bustard family, no galliform birds occur in New Guinea, and the pheasant pigeon has filled the ecological niche of a partridge or small pheasant. It is a secretive species, feeding on seeds and fallen fruits. It nests on the ground below trees and bushes, laying one egg that it incubates for around four weeks, the nominate subspecies and O. cervicalis are not considered threatened, although O. insularis qualifies as Endangered, and O. aruensis qualifies as Vulnerable. Because it is tied to primary forests, and is unique within the family, it is considered a genus that requires further investigation. Del Hoyo, Elliott and Sargatal, Handbook of the Birds of the World, ISBN 84-87334-22-9 Pheasant Pigeon is being split, list O. insularis as Endangered and O. aruensis as Vulnerable
. PMID 25504713.
