1.
Megaannum
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A year is the orbital period of the Earth moving in its orbit around the Sun. Due to the Earths axial tilt, the course of a year sees the passing of the seasons, marked by changes in weather, the hours of daylight, and, consequently, vegetation and soil fertility. In temperate and subpolar regions around the globe, four seasons are recognized, spring, summer, autumn. In tropical and subtropical regions several geographical sectors do not present defined seasons, but in the seasonal tropics, a calendar year is an approximation of the number of days of the Earths orbital period as counted in a given calendar. The Gregorian, or modern, calendar, presents its calendar year to be either a common year of 365 days or a year of 366 days, as do the Julian calendars. For the Gregorian calendar the average length of the year across the complete leap cycle of 400 years is 365.2425 days. The ISO standard ISO 80000-3, Annex C, supports the symbol a to represent a year of either 365 or 366 days, in English, the abbreviations y and yr are commonly used. In astronomy, the Julian year is a unit of time, it is defined as 365.25 days of exactly 86400 seconds, totalling exactly 31557600 seconds in the Julian astronomical year. The word year is used for periods loosely associated with, but not identical to, the calendar or astronomical year, such as the seasonal year, the fiscal year. Similarly, year can mean the period of any planet, for example. The term can also be used in reference to any long period or cycle, west Saxon ġēar, Anglian ġēr continues Proto-Germanic *jǣran. Cognates are German Jahr, Old High German jār, Old Norse ár and Gothic jer, all the descendants of the Proto-Indo-European noun *yeh₁rom year, season. Cognates also descended from the same Proto-Indo-European noun are Avestan yārǝ year, Greek ὥρα year, season, period of time, Old Church Slavonic jarŭ, Latin annus is from a PIE noun *h₂et-no-, which also yielded Gothic aþn year. Both *yeh₁-ro- and *h₂et-no- are based on verbal roots expressing movement, *h₁ey- and *h₂et- respectively, the Greek word for year, ἔτος, is cognate with Latin vetus old, from the PIE word *wetos- year, also preserved in this meaning in Sanskrit vat-sa- yearling and vat-sa-ras year. Derived from Latin annus are a number of English words, such as annual, annuity, anniversary, etc. per annum means each year, anno Domini means in the year of the Lord. No astronomical year has an number of days or lunar months. Financial and scientific calculations often use a 365-day calendar to simplify daily rates, in the Julian calendar, the average length of a year is 365.25 days. In a non-leap year, there are 365 days, in a year there are 366 days
2.
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
3.
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
4.
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
5.
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
6.
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
7.
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
8.
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
9.
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
10.
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
11.
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
12.
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
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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
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Pliocene
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The Pliocene Epoch is the epoch in the geologic timescale that extends from 5.333 million to 2.58 million years BP. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era, the Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch.588 to 1.806 million years ago, and is now included in the Pleistocene. As with other geologic periods, the geological strata that define the start and end are well identified but the exact dates of the start. The boundaries defining the Pliocene are not set at an easily identified worldwide event, the upper boundary was set at the start of the Pleistocene glaciations. The Pliocene was named by Sir Charles Lyell, the name comes from the Greek words πλεῖον and καινός and means roughly continuation of the recent, referring to the essentially modern marine mollusc faunas. H. W. Fowler called the term a regrettable barbarism, in the official timescale of the ICS, the Pliocene is subdivided into two stages. From youngest to oldest they are, Piacenzian Zanclean The Piacenzian is sometimes referred to as the Late Pliocene, in the system of North American Land Mammal Ages include Hemphillian, and Blancan. The Blancan extends forward into the Pleistocene, South American Land Mammal Ages include Montehermosan, Chapadmalalan and Uquian. In the Paratethys area the Pliocene contains the Dacian and Romanian stages, as usual in stratigraphy, there are many other regional and local subdivisions in use. In Britain the Pliocene is divided into the stages, Gedgravian, Waltonian, Pre-Ludhamian, Ludhamian, Thurnian, Bramertonian or Antian, Pre-Pastonian or Baventian, Pastonian and Beestonian. The exact correlations between these stages and the ICS stages is still a matter of detail. The formation of an Arctic ice cap is signaled by a shift in oxygen isotope ratios and ice-rafted cobbles in the North Atlantic. Mid-latitude glaciation was probably underway before the end of the epoch, the global cooling that occurred during the Pliocene may have spurred on the disappearance of forests and the spread of grasslands and savannas. Continents continued to drift, moving from positions possibly as far as 250 km from their present locations to positions only 70 km from their current locations, africas collision with Europe formed the Mediterranean Sea, cutting off the remnants of the Tethys Ocean. The border between the Miocene and the Pliocene is also the time of the Messinian salinity crisis, Sea level changes exposed the land-bridge between Alaska and Asia. Pliocene marine rocks are exposed in the Mediterranean, India. Elsewhere, they are exposed largely near shores, the change to a cooler, dry, seasonal climate had considerable impacts on Pliocene vegetation, reducing tropical species worldwide. Deciduous forests proliferated, coniferous forests and tundra covered much of the north, tropical forests were limited to a tight band around the equator, and in addition to dry savannahs, deserts appeared in Asia and Africa
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Pleistocene
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The Pleistocene is the geological epoch which lasted from about 2,588,000 to 11,700 years ago, spanning the worlds most recent period of repeated glaciations. The end of the Pleistocene corresponds with the end of the last glacial period, the Pleistocene is the first epoch of the Quaternary Period or sixth epoch of the Cenozoic Era. In the ICS timescale, the Pleistocene is divided into four stages or ages, all of these stages were defined in southern Europe. In addition to this subdivision, various regional subdivisions are often used. Charles Lyell introduced the term pleistocene in 1839 to describe strata in Sicily that had at least 70% of their molluscan fauna still living today and this distinguished it from the older Pliocene Epoch, which Lyell had originally thought to be the youngest fossil rock layer. The Pleistocene has been dated from 2.588 million to 11,700 years before present and it covers most of the latest period of repeated glaciation, up to and including the Younger Dryas cold spell. The end of the Younger Dryas has been dated to about 9640 BC, the IUGS has yet to approve a type section, Global Boundary Stratotype Section and Point, for the upper Pleistocene/Holocene boundary. The proposed section is the North Greenland Ice Core Project ice core 75°06 N 42°18 W, the lower boundary of the Pleistocene Series is formally defined magnetostratigraphically as the base of the Matuyama chronozone, isotopic stage 103. Above this point there are notable extinctions of the calcareous nanofossils, Discoaster pentaradiatus, the Pleistocene covers the recent period of repeated glaciations. The name Plio-Pleistocene has, in the past, been used to mean the last ice age. The revised definition of the Quaternary, by pushing back the date of the Pleistocene to 2.58 Ma. Pleistocene climate was marked by repeated glacial cycles in which continental glaciers pushed to the 40th parallel in some places and it is estimated that, at maximum glacial extent, 30% of the Earths surface was covered by ice. In addition, a zone of permafrost stretched southward from the edge of the sheet, a few hundred kilometres in North America. The mean annual temperature at the edge of the ice was −6 °C, during interglacial times, such as at present, drowned coastlines were common, mitigated by isostatic or other emergent motion of some regions. The effects of glaciation were global, antarctica was ice-bound throughout the Pleistocene as well as the preceding Pliocene. The Andes were covered in the south by the Patagonian ice cap, there were glaciers in New Zealand and Tasmania. The current decaying glaciers of Mount Kenya, Mount Kilimanjaro, glaciers existed in the mountains of Ethiopia and to the west in the Atlas mountains. In the northern hemisphere, many glaciers fused into one, the Cordilleran ice sheet covered the North American northwest, the east was covered by the Laurentide
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Australopithecus afarensis
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Australopithecus afarensis is an extinct hominin that lived between 3.9 and 2.9 million years ago. A. afarensis was slenderly built, like the younger Australopithecus africanus, a. afarensis is thought to be more closely related to the genus Homo, whether as a direct ancestor or a close relative of an unknown ancestor, than any other known primate from the same time. Some researchers include A. afarensis in the genus Praeanthropus, the most famous fossil is the partial skeleton named Lucy found by Donald Johanson and colleagues, who, in celebration of their find, repeatedly played the Beatles song Lucy in the Sky with Diamonds. Australopithecus afarensis fossils have only been discovered within Eastern Africa, despite Laetoli being the type locality for A. Other localities bearing A. afarensis remains include Omo, Maka, Fejej, and Belohdelie in Ethiopia, compared to the modern and extinct great apes, A. afarensis has reduced canines and molars, although they are still relatively larger than in modern humans. A. afarensis also has a small brain size and a prognathic face. Considerable debate surrounds the locomotor behaviour of A. afarensis, some studies suggest that A. afarensis was almost exclusively bipedal, while others propose that the creatures were partly arboreal. The anatomy of the hands, feet, and shoulder joints in many ways favour the latter interpretation, in particular, the morphology of the scapula appears to be ape-like and very different from modern humans. The curvature of the finger and toe bones approaches that of modern-day apes, alternatively, the loss of an abductable great toe and therefore the ability to grasp with the foot suggests A. afarensis was no longer adapted to climbing. A number of traits in the A. afarensis skeleton strongly reflect bipedalism, in overall anatomy, the pelvis is far more human-like than ape-like. The iliac blades are short and wide, the sacrum is wide and positioned directly behind the hip joint, importantly, the femur also angles in toward the knee from the hip. This trait would have allowed the foot to have closer to the midline of the body. The feet also feature adducted big toes, making it difficult if not impossible to grasp branches with the hindlimbs. The loss of a grasping hindlimb also increases the risk of an infant being dropped or falling, without the second set of grasping limbs, the infant cannot maintain as strong a grip, and likely had to be held with help from the mother. The problem of holding the infant would be multiplied if the mother also had to climb trees, bones of the foot also indicate bipedality. The upright gait would have much more efficient than the bent knee and hip walking. Yet, this can be questioned, as finds of Australopithecus foot bones indicate the Laetoli footprints may not have made by Australopithecus. Many scientists also doubt the suggestion of bipedalism, and argue that even if Australopithecus really did walk on two legs, it did not walk in the way as humans
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San Diego Museum of Man
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The San Diego Museum of Man is a museum of anthropology located in Balboa Park, San Diego, California and housed in the historic landmark buildings of the California Quadrangle. The museum traces its origins to the Panama-California Exposition, which opened in 1915 on the occasion of the inauguration of the Panama Canal. The central exhibit of the exposition, The Story of Man through the Ages, was assembled under the direction of noted archaeologist Dr. Edgar Lee Hewett of the School of American Archaeology. Hewett organized expeditions to gather pre-Columbian pottery from the American Southwest and to Guatemala for objects, osteological remains and trepanated crania from Peruvian sites were also obtained. Between 1935 and 1936, the name briefly changed to the Palace of Science in order to correspond with other exhibit buildings participating in the California-Pacific International Exposition. During this exposition, the museum housed several exhibitions from a variety of sources, such as the Monte Alban exhibit. The name was changed to Museum of Man in 1942 to emphasize the museums concentration on anthropology, San Diego was added in 1978. The museum was converted into a hospital during World War II, following the war, the museum began to focus its collections on the peoples of the Western Americas. The museum’s collections grew substantially from the 1980s through the early 1990s, the museum is housed in four original buildings from the 1915 Exposition. Those include the California Quadrangle, which was designed for the Exposition by American architect Bertram G. Goodhue, the Quadrangle and Tower are listed on the National Register of Historic Places. The exterior sculpture on the building was created by the Piccirilli Brothers, the main museum, including exhibits and gift shop, is housed in the ornate California Building with its landmark tower. The tower, closed to the public for nearly 80 years, reopened on January 1,2015, the tower contains a carillon and quarterly-hour chimes which can be heard all over Balboa Park. The museum also occupies three other original 1915 buildings, administrative offices and an auditorium are housed in the Gill Administration Building, immediately adjacent to the Museum on the west. Originally known as the Balboa Park Administration Building, it was built in 1911 and it was the first building erected in Balboa Park. On the opposite side of the California Quadrangle, housed in what was originally the Fine Arts Building, is Evernham Hall, immediately adjacent is the Saint Francis Chapel, a non-denominational Spanish-style chapel available for private events such as weddings. The most extraordinary of these is an extremely rare Ptolemaic childs coffin — only six others are known to exist worldwide, total holdings include more than 100,000 documented ethnographic items, more than 30,000 books and journals, and 25,000 photographic images. The exhibit explores ancient and modern beer types and brewing practices, as well as their connections to agriculture, religion. The exhibit also includes a full, hand-crafted bar, which provides the space for regular beer tasting events and this exhibit will be open through summer 2016
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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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Mammal
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Mammals are any vertebrates within the class Mammalia, a clade of endothermic amniotes distinguished from reptiles by the possession of a neocortex, hair, three middle ear bones and mammary glands. All female mammals nurse their young with milk, secreted from the mammary glands, Mammals include the largest animals on the planet, the great whales. The basic body type is a quadruped, but some mammals are adapted for life at sea, in the air, in trees. The largest group of mammals, the placentals, have a placenta, Mammals range in size from the 30–40 mm bumblebee bat to the 30-meter blue whale. With the exception of the five species of monotreme, all modern mammals give birth to live young, most mammals, including the six most species-rich orders, belong to the placental group. The largest orders are the rodents, bats and Soricomorpha, the next three biggest orders, depending on the biological classification scheme used, are the Primates, the Cetartiodactyla, and the Carnivora. Living mammals are divided into the Yinotheria and Theriiformes There are around 5450 species of mammal, in some classifications, extant mammals are divided into two subclasses, the Prototheria, that is, the order Monotremata, and the Theria, or the infraclasses Metatheria and Eutheria. The marsupials constitute the group of the Metatheria, and include all living metatherians as well as many extinct ones. Much of the changes reflect the advances of cladistic analysis and molecular genetics, findings from molecular genetics, for example, have prompted adopting new groups, such as the Afrotheria, and abandoning traditional groups, such as the Insectivora. The mammals represent the only living Synapsida, which together with the Sauropsida form the Amniota clade, the early synapsid mammalian ancestors were sphenacodont pelycosaurs, a group that produced the non-mammalian Dimetrodon. At the end of the Carboniferous period, this group diverged from the line that led to todays reptiles. Some mammals are intelligent, with some possessing large brains, self-awareness, Mammals can communicate and vocalize in several different ways, including the production of ultrasound, scent-marking, alarm signals, singing, and echolocation. Mammals can organize themselves into fission-fusion societies, harems, and hierarchies, most mammals are polygynous, but some can be monogamous or polyandrous. They provided, and continue to provide, power for transport and agriculture, as well as commodities such as meat, dairy products, wool. Mammals are hunted or raced for sport, and are used as model organisms in science, Mammals have been depicted in art since Palaeolithic times, and appear in literature, film, mythology, and religion. Defaunation of mammals is primarily driven by anthropogenic factors, such as poaching and habitat destruction, Mammal classification has been through several iterations since Carl Linnaeus initially defined the class. No classification system is accepted, McKenna & Bell and Wilson & Reader provide useful recent compendiums. Though field work gradually made Simpsons classification outdated, it remains the closest thing to a classification of mammals
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Primate
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A primate is a mammal of the order Primates. In taxonomy, primates include two distinct lineages, strepsirrhines and haplorhines, Primates arose from ancestors that lived in the trees of tropical forests, many primate characteristics represent adaptations to life in this challenging three-dimensional environment. Most primate species remain at least partly arboreal, with the exception of humans, who inhabit every continent except for Antarctica, most primates live in tropical or subtropical regions of the Americas, Africa and Asia. Based on fossil evidence, the earliest known true primates, represented by the genus Teilhardina, an early close primate relative known from abundant remains is the Late Paleocene Plesiadapis, c. Molecular clock studies suggest that the branch may be even older. The order Primates was traditionally divided into two groupings, prosimians and anthropoids. Prosimians have characteristics more like those of the earliest primates, and include the lemurs of Madagascar, lorisoids, simians include monkeys, apes and hominins. Simians are divided into two groups, catarrhine monkeys and apes of Africa and Southeast Asia and platyrrhine or New World monkeys of South, catarrhines consist of Old World monkeys, gibbons and great apes, New World monkeys include the capuchin, howler and squirrel monkeys. Humans are the only extant catarrhines to have spread successfully outside of Africa, South Asia, New primate species are still being discovered. More than 25 species were described in the decade of the 2000s. Considered generalist mammals, primates exhibit a range of characteristics. Some primates are primarily terrestrial rather than arboreal, but all species possess adaptations for climbing trees, locomotion techniques used include leaping from tree to tree, walking on two or four limbs, knuckle-walking, and swinging between branches of trees. Primates are characterized by large brains relative to other mammals, as well as a reliance on stereoscopic vision at the expense of smell. These features are developed in monkeys and apes and noticeably less so in lorises. Three-color vision has developed in some primates, most also have opposable thumbs and some have prehensile tails. Many species are dimorphic, differences include body mass, canine tooth size. Primates have slower rates of development than other similarly sized mammals and reach maturity later, depending on the species, adults may live in solitude, in mated pairs, or in groups of up to hundreds of members. The relationships among the different groups of primates were not clearly understood until relatively recently, for example, ape has been used either as an alternative for monkey or for any tailless, relatively human-like primate
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Haplorhini
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Haplorrhini is a clade containing the tarsiers and the simians. The name is also spelt Haplorrhini, the simians include catarrhines, and the platyrrhines. The extinct omomyids, which are considered to be the most basal haplorhines, are believed to be closely related to the tarsiers than to other haplorhines. Haplorhines share a number of derived features that distinguish them from the strepsirrhine wet-nosed primates, the haplorhine upper lip, which has replaced the ancestral rhinarium found in strepsirrhines, is not directly connected to their nose or gum, allowing a large range of facial expressions. Their brain-to-body mass ratio is greater than the strepsirrhines. Haplorhines have a plate, unlike the postorbital bar found in strepsirrhines. All anthropoids have a uterus, tarsiers have a bicornate uterus like the strepsirrhines. Most species typically have single births, although twins and triplets are common for marmosets, despite similar gestation periods, haplorhine newborns are relatively much larger than strepsirrhine newborns, but have a longer dependence period on their mother. This difference in size and dependence is credited to the complexity of their behavior. The taxonomic name Haplorhini derives from the Ancient Greek haploûs and rhinos and it refers to the lack of a rhinarium or wet nose, which is found in many mammals, including strepsirrhine primates. Haplorhini and its sister clade, Strepsirrhini, diverged about 65 million years ago, the fossil Archicebus may be similar to the most recent common ancestor at this time. The other major clade within Haplorhini, the simians, is divided into two parvorders, Platyrrhini and Catarrhini, the New World monkeys split from catarrhines about 40 mya, while the apes diverged from Old World monkeys about 25 mya. The available fossil evidence indicates both the hominoid and cercopithecoid clades originated in Africa. The following is the listing of the living families, and their placement in the Order Primates, ORDER PRIMATES Suborder Strepsirrhini, lemurs, lorises
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Simian
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The simians are the monkeys, cladistically including the apes, the New World monkeys or platyrrhines, and the catarrhine clade consisting of the Old World monkeys and apes. The simian line and the line diverged about 60 million years ago. Forty million years ago, simians from Africa colonized South America, the remaining simians split 25 million years ago into apes and Old World monkeys. Under modern classification, the tarsiers and simians are grouped under the suborder Haplorhini while the strepsirrhines are placed in suborder Strepsirrhini, in anthropoidea, evidences indicate that the Old and the New World primates went through parallel evolution. Primatology, paleoanthropology, and other related fields are split on their usage of the synonymous infraorder names, Simiiformes and Anthropoidea. According to Robert Hoffstetter, the term Simiiformes has priority over Anthropoidea because of the taxonomic term Simii by van der Hoeven, from which it is constructed, dates to 1833. In contrast, Anthropoidea by Mivart dates to 1864, while Simiiformes by Haeckel dates to 1866, Hoffstetter also argued that Simiiformes is also constructed like a proper infraorder name, whereas Anthropoidea ends in -oidea, which is reserved for superfamilies. He also noted that Anthropoidea is too easily confused with anthropoïdes, the simians are split into three distinct groups. The New World monkeys in parvorder Platyrrhini split from the rest of the line about 40 mya. This group split about 25 mya between the Old World monkeys and the apes
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Hominidae
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Several revisions in classifying the great apes have caused the use of the term hominid to vary over time. Its original meaning referred only to humans and their closest non-extant relatives and that restrictive meaning has now been largely assumed by the term hominin, which comprises all members of the human clade after the split from the chimpanzees. The current, 21st-century meaning of hominid includes all the great apes including humans, the most recent common ancestor of all Hominidae lived roughly 14 million years ago, when the ancestors of the orangutans speciated from the ancestral line of the other three genera. Those ancestors of the family Hominidae had already speciated from the family Hylobatidae, in the early Miocene, about 22 million years ago, there were many species of arboreally adapted primitive catarrhines from East Africa, the variety suggests a long history of prior diversification. Fossils at 20 million years ago include fragments attributed to Victoriapithecus, the most recent of these far-flung Miocene apes is Oreopithecus, from the fossil-rich coal beds in northern Italy and dated to 9 million years ago. Species close to the last common ancestor of gorillas, chimpanzees and humans may be represented by Nakalipithecus fossils found in Kenya and Ouranopithecus found in Greece. Molecular evidence suggests that between 8 and 4 million years ago, first the gorillas, and then the split off from the line leading to the humans. Human DNA is approximately 98. 4% identical to that of chimpanzees when comparing single nucleotide polymorphisms, the earliest fossils argued by some to belong to the human lineage are Sahelanthropus tchadensis and Orrorin tugenensis, followed by Ardipithecus, with species Ar. kadabba and Ar. ramidus. The classification of the apes has been revised several times in the last few decades. The original meaning of the referred to only humans and their closest relatives—what is now the modern meaning of the term hominin. And the meaning of the taxon Hominidae changed gradually, leading to a different usage of hominid that today all the great apes including humans. A hominid is a member of the family Hominidae, the apes, orangutans, gorillas, chimpanzees. A hominine is a member of the subfamily Homininae, gorillas, chimpanzees, a hominin is a member of the tribe Hominini, Chimpanzees and humans. A homininan is a member of the subtribe Hominina of the tribe Hominini, a human is a member of the genus Homo, of which Homo sapiens is the only extant species, and within that Homo sapiens sapiens is the only surviving subspecies. For each clade it is indicated approximately when newer extant clades emerged, some texts will refer to Homonini as the Hominina branch. Many scientists, including paleoanthropologists, continue to use the term hominid to mean humans, as mentioned, Hominidae was originally the name given to the family of humans and their close relatives, with the other great apes all being placed in a separate family, the Pongidae. However, that eventually made Pongidae paraphyletic because at least one great ape species proved to be more closely related to humans than to other great apes. Most taxonomists today encourage monophyletic groups—this would require, in this case, thus, many biologists now assign Pongo to the family Hominidae
26.
Homininae
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Homininae is a subfamily of Hominidae. It includes two tribes, with their extant as well as species, the Hominini tribe. It comprises all hominids that arose after orangutans split from the line of great apes, the Homininae cladogram has three main branches, which lead to gorillas, and to humans and chimpanzees via the tribe Hominini and subtribes Hominina and Panina. There are two living species of Panina and two living species of gorillas, but only one extant human species, traces of hypothetical Homo species, including Homo floresiensis and Homo denisova, have been found with dates as recent as 12,000 years ago. Organisms in this class are described as hominine or hominines, until 1980, the family Hominidae meant humans only, the non-human great apes were assigned to the family Pongidae. The subfamily Homininae can be subdivided into three branches, the tribe Gorillini, and the tribe Hominini with subtribes Panina and Hominina. Their existence suggests that the Homininae tribes diverged not earlier than about 8 million years ago, today, chimpanzees and gorillas live in tropical forests with acid soils that rarely preserve fossils. This shows that some chimpanzees lived close to Homo at the time, australopithecus and early Paranthropus may have been bipedal. Very early hominins such as Ardipithecus ramidus may have possessed a type of bipedalism. It is proposed that they evolved from H. erectus as a case of insular dwarfism, in spite of their smaller brain, there is evidence that H. floresiensis used fire and made stone tools at least as sophisticated as those of their proposed ancestors H. erectus. In this case, it seems that for intelligence, the structure of the brain is more important than its size, sexuality is related to family structure and partly shapes it. The involvement of fathers in education is unique to humans. Concealed ovulation and menopause in women both also occur in a few other primates however, but are uncommon in other species, testis and penis size seems to be related to family structure, monogamy or promiscuity, or harem, in humans, chimpanzees or gorillas, respectively. The levels of sexual dimorphism are seen as a marker of sexual selection. Concealed ovulation means that the phase of fertility is not detectable in women, women can be partly aware of their ovulation along the menstrual phases, but men are essentially unable to detect ovulation in women. Menopause also occurs in rhesus monkeys, and possibly in chimpanzees, chimpanzee-human last common ancestor List of human evolution fossils Human Timeline – Smithsonian, National Museum of Natural History
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Hominini
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Members of the human clade, that is, the Hominina, including Homo and those species of the australopithecines that arose after the split from the chimpanzees, are called homininans. Not all homininans are directly related to the emergence of early Homo and this is a modern cladogram, For each clade, the cladogram above shows approximately when newer extant clades emerged. Some texts refer to Homonini as the Hominina branch, the subtribe Hominina is the human branch, that is, it contains only the genus Homo. Researchers proposed the taxon Hominini on the basis that the least similar species of a trichotomy should be separated from the other two. The common chimpanzee and the bonobo of the genus Pan are the closest living relatives to humans. All the extinct genera listed to the right are ancestral to, or offshoots of, however, both Orrorin and Sahelanthropus existed around the time of the split, and so may be ancestral to both Pan and Homo. In the proposal of Mann and Weiss, the tribe Hominini includes Pan as well as Homo, Homo and all bipedal apes are referred to the subtribe Hominina, while Pan is assigned to the subtribe Panina. Wood discusses the different views of this taxonomy, the assumption of late hybridization was in particular based on the similarity of the X chromosome in humans and chimpanzees, suggesting a divergence as late as some 4 million years ago. Sahelanthropus tchadensis is an extinct species that lived seven million years ago. Human Timeline – Smithsonian, National Museum of Natural History
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Australopithecine
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Australopithecines are generally all species in the related Australopithecus and Paranthropus genera, and it typically includes Kenyanthropus, Ardipithecus, and Praeanthropus. All these related species are now sometimes collectively classified as a subtribe of the Hominini tribe called Australopithecina and they are the extinct, close relatives of humans and, with the extant genus Homo, comprise the human clade. Members of the clade, i. e. the Hominini after the split from the chimpanzees, are now called homonina. The terms australopithecine, et al. come from a classification as members of a distinct subfamily. Members of Australopithecus are sometimes referred to as the gracile australopithecines, humans may have descended from australopithecine ancestors and the genus Ardipithecus is a possible ancestor of the australopithecines. Phylogeny of subtribe Australopithecina according to Briggs & Crowther 2008, p.124 and they have a high brachial index when compared to other hominins, and they exhibit greater sexual dimorphism than members of Homo or Pan but less so than Gorilla or Pongo. It is thought that they averaged heights of 1. 2–1.5 metres, the brain size may have been 350 cc to 600 cc. Most scientists maintain that one of the species evolved into the Homo genus in Africa around two million years ago. Nearly every possible species has been suggested as a likely candidate, presently, it appears that A. garhi has the potential to occupy this coveted place in paleoanthropology, but the lack of fossil evidence is a serious problem. Another problem presents itself in the fact that it has very difficult to assess which hominid represents the first member of the genus Homo. Without knowing this, it is not possible to determine which species of australopithecine may have been ancestral to Homo, marc Verhaegen has argued that an australopithecine species could have also been ancestral to the Pan genus. A minority held viewpoint among palaeoanthropologists is that australopithecines moved outside of Africa, a notable proponent of this theory is Jens Lorenz Franzen, formerly Head of Paleoanthropology at the Research Institute Senckenberg. In 1957, an Early Pleistocene Chinese fossil tooth of unknown province was described as resembling P. robustus, three fossilized molars from Jianshi, China were later identified as belonging to an Australopithecus species. However further examination questioned this interpretation, Zhang argued the Jianshi teeth, but, Wolpoff notes that in China persistent claims of australopithecine or australopithecine-like remains continue. Dawn of Humanity Human taxonomy Informative lecture on Australopithecines
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Raymond Dart
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Raymond Dart was born in Toowong, a suburb of Brisbane, Queensland, Australia, the fifth of nine children and son of a farmer and tradesman. His birth occurred during the 1893 flood which filled his parents home, the family moved alternately between their country property near Laidley and their shop in Toowong. The young Dart attended Toowong State School, Blenheim State School and he was a member of the first intake of students to the University in 1911 and studied geology under H. C. Richards and zoology, taking his B. Sc. in 1913, Dart became the first student to graduate with honours from the University of Queensland in 1914 and took his M. Sc. with honours from UQ in 1916. He studied medicine at the University of Sydney taking his MB and M. Surgery in 1917 and he would be awarded his M. D. from the University of Sydney in 1927. Dart served as a captain and medic in the Australian Army in England and this would be followed by a year on a Rockefeller Foundation Fellowship at Washington University, St Louis, Missouri. In 1924, Dart discovered the first Australopithecus africanus fossil, an extinct hominin closely related to humans. His colleague, Professor Robert Burns Young from the Buxton Limeworks, had sent Dart two crates of fossils from the town of Taung in the North West Province of South Africa. Upon seeing the fossils, Dart immediately recognized one as being a human because its brain dimensions were too large for a baboon or chimpanzee. Blasting had exposed a cave and the childs skull had come to light together with several fossilized monkeys. M. de Bruyn had noticed their unusual nature in November 1924 and informed the Limeworks manager, Mr. A. E. Spiers. Darts closest ally was Robert Broom whose discoveries of further Australopithecines eventually vindicated Dart, so much so that in 1947 Sir Arthur Keith said. Dart was right, not all of Darts theories would in the end be vindicated. A number of his theories including that of the Killer Ape, have called into question. His work was influenced by the mentors he worked with in his early career. Raymond Dart proposed the idea of dual origins of the neocortex. During his research in 1930s in Africa, he studied the architecture of reptilian brains and he was able to identify a premordial neocortex, the oldest structure that can be considered as a neocortex, in a reptile. He identified a distinction between the cytoarchitecture in an area which split it into a Para-Hippocampal and a Para-Pyriform region, Dart married Dora Tyree, a medical student from Virginia, in 1921 in Woods Hole, Massachusetts and they divorced in 1934. He married Marjorie Frew, head librarian at the University of Witwatersrand in Johannesburg, South Africa in 1936, the Institute for the Study of Man in Africa was established in 1956 at Witwatersrand in his honor
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Type species
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A similar concept is used for suprageneric groups called a type genus. In botanical nomenclature, these terms have no standing under the code of nomenclature. In botany, the type of a name is a specimen which is also the type of a species name. The species name that has that type can also be referred to as the type of the genus name, names of genus and family ranks, the various subdivisions of those ranks, and some higher-rank names based on genus names, have such types. In bacteriology, a species is assigned for each genus. Every named genus or subgenus in zoology, whether or not currently recognized as valid, is associated with a type species. In practice, however, there is a backlog of untypified names defined in older publications when it was not required to specify a type, a type species is both a concept and a practical system that is used in the classification and nomenclature of animals. The type species represents the species and thus definition for a particular genus name. In the Glossary, type species is defined as The nominal species that is the type of a nominal genus or subgenus. The type species permanently attaches a formal name to a genus by providing just one species within that genus to which the name is permanently linked. The species name in turn is fixed, in theory, to a type specimen, for example, the type species for the land snail genus Monacha is Monacha cartusiana. That genus is placed within the family Hygromiidae. The type genus for that family is the genus Hygromia, the concept of the type species in zoology was introduced by Pierre André Latreille. The International Code of Zoological Nomenclature states that the name of the type species should always be cited. It gives an example in Article 67.1, Astacus marinus Fabricius,1775 was later designated as the type species of the genus Homarus, thus giving it the name Homarus marinus. However, the species of Homarus should always be cited using its original name. 3, the type of the genus name Elodes is quoted as the type of the species name Hypericum aegypticum, Glossary of scientific naming Genetypes – genetic sequence data from type specimens. Holotype Paratype Principle of Typification Type Type genus
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Australopithecus africanus
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Australopithecus africanus is an extinct species of the australopithecines, the first of an early -form species to be classified as hominin. Recently it was dated as living between 3.3 and 2.1 million years ago, or in the late Pliocene and early Pleistocene times, it is debated as being a direct ancestor of modern humans. A. africanus was of slender, or gracile, build and has found only in southern Africa at four sites, Taung, Sterkfontein, Makapansgat. Dart assigned the specimen the name Australopithecus africanus, it was dubbed the Taung child. This was the first time the word ape was formally assigned to any hominin, Dart theorized the Taung child skull must represent an intermediate species between apes and humans. And the rejection was buttressed by the widespread belief then, especially in British academia and he dismissed Darts claim, suggesting instead that the Taung child skull belonged to a young ape, most likely an infant gorilla or chimpanzee. Keith immersed himself in defending the Piltdown man and his reputation suffered greatly after the hoax was exposed in 1953, phillip Tobias, in a lengthy essay published in Current Anthropology in 1992, detailed the history of the investigation of the hoax. As part of the essay Tobias debated the inconsistencies in Keiths statements, Darts theory—that the skull known as the Taung child was a human ancestor—was supported by Robert Broom, a paleontologist with the Transvaal Museum of natural history in Pretoria. In 1936, the Sterkfontein caves yielded the first adult australopithecine, later, Broom classified an adult endocranial cast having a brain capacity of 485 cc as Plesianthropus transvaalensis. In April 1947, while blasting at Sterkfontein, he and John T. Robinson discovered a skull belonging to a female which he also classified as Plesianthropus transvaalensis. Both fossils were classified as Australopithecus africanus. Mrs. Ples, whose capacity is only about 485 cubic centimetres, was one of the first fossils to reveal that upright walking had evolved well before any significant growth in brain size. And, in comparison to modern apes, Dart noted as with the Taung child the lack of facial projection and it has slightly human-like, advanced cranial features, but also presents primitive features including ape-like curved fingers adapted to tree climbing. Both P. robustus and A. africanus crania seem very alike despite the heavily built features of P. robustus. A. africanus had a pelvis that would enable more efficient bipedalism than that of A. afarensis, such a morphology would support an earlier time for making and using tools than previously had been thought likely. Evidence of human-like sexual dimorphism in the spine has recently been described in the primate A. africanus. Recent analysis of the Little Foot specimen dated it to about 3, the Makapansgat fossils have been dated to between 3.0 and 2.6 mya. Those at Sterkfontein currently are dated to between 2.6 and 2.0 mya with the Mrs Ples fossil dating to around 2.0 million years, and Gladysvale fossils were dated between about 2.4 and 2.0 mya
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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
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Australopithecus garhi
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The hominin remains are believed to be a human ancestor species and possibly the direct ancestor to the human genus, Homo. Tim White was the scientist to find the first of the key A. garhi fossils in 1996 in the Bouri Formation, the species was confirmed and established as A. garhi on November 20,1997 by the Ethiopian paleoanthropologist Yohannes Haile-Selassie. The species epithet garhi means surprise in the local Afar language, the traits of A. garhi fossils such as BOU-VP-12/130 are somewhat distinctive from traits typically seen in Australopithecus afarensis and Australopithecus africanus. An example of the distinction can be seen comparing the Hadar maxilla to the Bouri specimen of A. garhi. The cranial capacity of A. garhi measures 450cc, the size as other australopithecines. Studies made on the premolars and molar teeth have a few similarities with those of Paranthropus boisei since they are larger than any other form of australopithecine. It has been suggested that if A. garhi is ancestral to Homo the maxillary morphology would have undergone a rapid change in roughly 200,000 and 300,000 years. Few primitive shaped stone tool artifacts closely resembling Olduwan technology were discovered with the A. garhi fossils, the tools are suggested to be older than those acquired by Homo habilis, which is thought to be a possible direct ancestor of more modern hominins. For a long time assumed that only members of early genus Homo had the ability to produce sophisticated tools. However, the ancient tools lack several techniques that are generally seen in later forms Olduwan and Acheulean such as strong rock-outcroppings. In another site in Bouri, Ethiopia, roughly 3,000 stone artifacts had been found to be an estimated 2.5 million years old in age, List of fossil sites List of human evolution fossils Australopithecus garhi. The Smithsonian Institutions Human Origins Program, the Earliest Human Ancestors, New Finds, New Interpretations. Archived from the original on December 23,2010, Australopithecus garhi, A New Species of Early Hominid from Ethiopia. Archived from the original on June 7,2011, Human Timeline – Smithsonian, National Museum of Natural History
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Australopithecus sediba
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Australopithecus sediba is a species of Australopithecus of the early Pleistocene, identified based on fossil remains dated to about 2 million years ago. The fossils were found together at the bottom of the Malapa Cave, where they fell to their death. Over 220 fragments from the species have recovered to date. MH1 is disarticulated and 34% complete if skeletal elements known to be in a block are included while MH2 is 45. 6% complete. Australopithecus sediba may have lived in savannas but ate fruit and other foods from the similar to modern-day savanna chimpanzees. The conditions in which the individuals were buried and fossilized were extraordinary, the first specimen of A. sediba was found by paleoanthropologist Lee Bergers nine-year-old son, Matthew, on August 15,2008. While exploring near his fathers dig site in the hills north of Johannesburg, on the Malapa Nature Reserve. The boy alerted his father to the find, who could not believe what he saw — a hominid clavicle, upon turning the block over, sticking out of the back of the rock was a mandible with a tooth, a canine, sticking out. And I almost died, he later recalled, the fossil turned out to belong to a 4 ft 2 in juvenile male, whose skull was discovered in March 2009 by Bergers team. The find was announced to the public on April 8,2010, also found at the Malapa archeological site were a variety of animal fossils, including saber-toothed cats, mongooses, and antelopes. Berger and geologist Paul Dirks speculated that the animals might have fallen into a deep 100–150-foot death-trap, the bodies may have then been swept into a pool of water with a sandy bottom and rich with lime, allowing the remains to become fossilized. The fossil was dated using a combination of palaeomagnetism and uranium-lead dating which showed that the fossils are no older than ~2.0 Ma, the presence of animal species which became extinct at ~1.5 Ma indicates the deposit is no younger than 1.5 Ma. The sediments have a normal polarity and the only major period between 2.0 and 1.5 Ma when this occurred is the Olduvai sub-Chron between 1.95 and 1.78 Ma. Accordingly, the fossils were dated to ~1.95 Ma. Recent dating of a capping flowstone demonstrated this was not possible, however, the cusp spacing is more like Australopithecus. The femur and tibia are fragmentary, but the foot combines an advanced anklebone combined with a primitive heel and its cranial capacity is estimated at around 420–450 cm3, about one-third that of modern humans. A. sediba had a modern hand, whose precision grip suggests it might have been another tool-making Australopithecus. Evidence of the precision gripping and stone tool production can be seen from Homo-like features such as having a long thumb, the nearly complete wrist and hand of an adult female from Malapa, South Africa presents Australopithecus-like features, such as a strong flexor apparatus associated with arboreal locomotion
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Paranthropus
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Paranthropus is a genus of extinct hominins. Also known as robust australopithecines, they were bipedal hominids that probably descended from the gracile australopithecine hominids 2.7 million years ago, however, Paranthropus skulls lack the transverse cranial crests that are also present in modern gorillas. A partial cranium and mandible of Paranthropus robustus was discovered in 1938 by a schoolboy, Gert Terblanche and it was described as a new genus and species by Robert Broom of the Transvaal Museum. The site has been excavated since 1993 by Francis Thackeray of the Transvaal Museum, a date of at least 1.95 million years has been obtained for Kromdraai B. Paranthropus boisei was discovered by Mary Leakey on July 17,1959, Mary was working alone, as Louis Leakey was ill in camp. She rushed back to camp and, at the news, Louis made a remarkable recovery and they refrained from excavating until Des Bartlett had photographed the site. In his notes Louis recorded a first name, Titanohomo mirabilis, Louis and Mary began to call it Dear Boy. Recovery was halted on August 7, Dear Boy was found in context with Oldowan tools and animal bones. The fossil was published in Nature dated August 15,1959, in it Louis placed the fossil in Brooms Australopithecinae family, creating a new genus for it, Zinjanthropus, species boisei. Zinj is an ancient Arabic word for the coast of East Africa and boisei referred to Charles Watson Boise, Louis based his classification on twenty differences from Australopithecus. Broom had died in 1951 but Dart was still living and he is said to have wept for joy on Louis behalf on being personally shown Zinj, which Louis and Mary carried around in a tin. Louis had considered Brooms Paranthropus genus, but rejected it because he believed Zinj was in the Homo ancestral stock and he relied heavily on the larger size of Zinjs canines. At that time palaeoanthropology was in a mood to lump and was preaching against splitting. Dart rescued him with the now famous joke, what would have happened if Mrs. Ples had met Dear Boy one dark night. The battle of the name raged on for years and drove a wedge between Louis and Sir Wilfrid LeGros Clark, from 1955, who took the Paranthropus view. On the other hand, it brought the Leakeys and Dr. Melville Bell Grosvenor of the National Geographic Society together, the Leakeys became international figures and had no trouble finding funds from then on. The Zinj question ultimately became part of the Australopithecus/Paranthropus question, all species of Paranthropus were bipedal, and many lived during a time when species of the genus Homo, were prevalent. Paranthropus first appeared roughly 2.7 million years ago, most species of Paranthropus had a brain about 40 percent of the size of a modern human
36.
Paranthropus aethiopicus
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Paranthropus aethiopicus or Australopithecus aethiopicus is an extinct species of hominin, one of the robust australopithecines. The first specimen of Australopithecus aethiopicus that was discovered is known as Omo 18, Omo 18, also known as Paraustralopithecus aethiopicus was discovered in southern Ethiopia by French archeologists Camille Arambourg and Yves Coppens in 1967. Omo 18 serves as a predecessor to KNM-WT17000, which was discovered by Alan Walker, the finding discovered in 1985 by Alan Walker in West Turkana, Kenya, KNM WT17000, is one of the earliest examples of robust pliocene hominids. A key feature of Omo 18 is that it has a v-shaped jaw unlike the other Australopithecus species found, although Omo 18 was the first skull discovered of these species, many paleoanthropologists ignored the finding on the basis that it was similar to the other species of australopithecines. Once KNM-WT17000 was discovered, interest renewed in Omo 18, Australopithecus aethiopicus is categorized into a group known as the robust australopithecines. The robust australopithecines are split into three species, Australopithecus aethiopicus, Australopithecus robustus, and Australopithecus boisei, there has been an ongoing debate over the exact phyletic origins of each of these species. The robust australopithecines share many characteristics of the cranium and mandible, Australopithecus aethiopicus has notable features that differ from the other robust australopithecines, including a larger zygomatic arch, extended ramus of the mandible, and a more prognathic face. These differences may have developed during the evolution of aethiopicus. The skull is dated to 2.5 million years ago, anthropologists suggest that P. aethiopicus lived between 2.7 and 2.5 million years ago. The features are primitive and share many traits with Australopithecus afarensis. Lower jaw and teeth fragments have been uncovered, P. aethiopicus had a large sagittal crest and zygomatic arch adapted for heavy chewing. Not much is known about this species since the best evidence comes from the Black Skull, there is not enough material to make an assessment of how tall they were, but they may have been as tall as Australopithecus afarensis. Paranthropus aethiopicus is considered a megadont archaic hominin, the term megadont referring to the size of the postcanine tooth crowns. The initial discovery was an adult mandible in the Shungura formation of the Omo region of Ethiopia in 1967. The ash layers above and below the fossils give a date of 2. 3-2.5 mya. There is only one complete skull for this hominin, so it’s hard to make proper inferences about physical characteristics. However, it can be said that the skull is similar to P. boisei, although the incisors are larger, the face more prognathic. Not all anthropologists agree that P. aethiopicus evolved into both Paranthropus boisei and Paranthropus robustus, since the more closely resembles that of A. afarensis
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Paranthropus robustus
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Paranthropus robustus is an early hominin, originally discovered in Southern Africa in 1938. Particularly regarding cranial features, the development of P. robustus seemed to be in the direction of a heavy-chewing complex, on account of the definitive traits associated with this robust line of australopithecine, anthropologist Robert Broom established the genus Paranthropus and placed this species in it. Paranthropus robustus is generally dated to have lived between 2.0 and 1.2 million years ago and it had large jaws and jaw muscles with the accompanying sagittal crest, and post-canine teeth that were adapted to serve in the dry environment they lived in. After Raymond Dart’s discovery of Australopithecus africanus, Broom was in favour of Darts claim that Australopithecus africanus was an ancestor of Homo sapiens, however, there was a great deal of skepticism and criticism from the academic community. Many claimed that Dart had been premature in naming the species, as the type specimen and it was thought that such important claims should be based on a full skeleton of an adult. Robert Broom was a Scottish doctor then working in South Africa who began making his own excavations in Southern Africa to find specimens of A. africanus. It was his intent to find complete adult skeletons that would justify the species designation of A. africanus, the fossils included parts of a skull and teeth, all dated to 2 million years old. Sites with fossils of Paranthropus robustus are found only in South Africa, in the cave at Swartkrans, the remains of 130 individuals were discovered. The study made on the dentition of the revealed that the average P. robustus rarely lived past 17 years of age. Paranthropus robustus was the first discovery of a robust species of hominin, it was well before P. boisei. These three species have alternately been in their own or placed within the genus Australopithecus and this is partly because in many small details, the species robustus resembles A. africanus more than it does either of the other robust species, aethiopicus or boisei. Brooms discovery was the second australopithecine after Australopithecus africanus, typical of robust australopithecines, P. robustus had a head shaped a bit like a gorillas with a more massive built jaw and teeth in comparison to hominins within the Homo lineage. The sagittal crest that runs from the top of the acts as an anchor for large chewing muscles. The teeth of these primates were larger and thicker than any gracile australopithecine found, on the skull, a bony ridge is located above from the front to back indicating where the jaw muscles joined. P. robustus males may have stood only 1. 2m tall and weighed 54 kg while females stood just under 1 meter tall and weighed only 40 kg, the teeth found on P. robustus are almost as large as those of P. boisei. Broom analyzed his findings carefully and noted the differences in the molar teeth size which resembled a gorillas a bit more than a humans, other P. robustus remains have been found in Southern Africa. The average brain size of P. robustus measured to only 410 and 530 cc, some have argued that P robustus had a diet of hard gritty foods such as nuts and tubers since they lived in open woodland and savanna
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Paranthropus boisei
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Paranthropus boisei or Australopithecus boisei was an early hominin, described as the largest of the Paranthropus genus. It lived in Eastern Africa during the Pleistocene epoch from about 2.4 until about 1.4 million years ago, Paranthropus boisei proved to be a treasure, especially when the anthropologists son Richard Leakey suggested it was the first hominin species to use stone tools. Bernard Wood of the University of Liverpool, England, posits that tools discovered in Ethiopia, a well-preserved jaw, known as the Peninj Mandible, was found by Richards colleague Kamoya Kimeu in 1964 in Peninj, Tanzania. Another skull, specimen KNM ER406, was unearthed in 1969 by Richard at Koobi Fora near Lake Turkana, the brain volume is quite small, about 500 to 550 cm³, not much larger than Australopithecus afarensis and Australopithecus africanus or modern-day chimpanzees. In P. boisei the foramen magnum is much shorter than in P. robustus, in, addition, the cranial variation of P. boisei is remarkably high. The adult males were larger on average than females, as was the case in virtually all australopithecine species, males weighed some 49 kg and stood about 1.37 m tall, while females weighed about 34 kg and were 1.24 m tall. It had a highly specialized for heavy chewing and several traits seen in modern-day gorillas. The molar teeth were large, with an area over twice that of modern humans. The species is referred to as “Nutcracker Man” because it had the biggest, flattest cheek teeth. Boisei had large chewing muscles attached to a sagittal crest. To accommodate their enormous cheek teeth, P. boisei had a wide face, some argue that the craniodental morphology of this taxon is indicative of a diet of hard or tough foods such as ground tubers, nuts and seeds. This work suggests that hard foods were an infrequent part of P. boiseis diet, carbon isotope ratios suggest P. boisei had a diet dominated by C4 vegetation, unlike P. robustus in South Africa. In 1993, A. Amzaye found fossils of P. boisei at Konso, the partial skull is designated as KGA10-525 and is dated to 1.4 million years ago. It is the biggest skull specimen ever found of P. boisei, OH5 Zinjanthropus, Zinj or Nutcracker Man, was the first P. boisei specimen found by Mary Leakey at Olduvai Gorge, Tanzania, it belonged to an adult male. The name Nutcracker Man may be a misnomer as it may apply to Paranthropus robustus. KNM ER406 is a partial cranium discovered by Richard Leakey and H. Mutua in 1969, found at Koobi Fora, Kenya, which displays large zygomatic arches. KNM WT17000 is a cranium, with similar characteristics to KNM WT17000, Black skull, belonging to Paranthropus aethiopicus. Peninj Mandible is a jaw, found by Kamoya Kimeu in the Lake Natron region
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Australopithecus anamensis
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Australopithecus anamensis is a stem-human species that lived approximately four million years ago. Nearly one hundred specimens are known from Kenya and Ethiopia. It is accepted that A. anamensis is ancestral to A. afarensis, fossil evidence determines that the Australopithecus anamensis is the earliest hominin species in the Turkana Basin. Due to an inability to retrieve a collection of fossils researchers are not able to make enough observations to differentiate a lot of the early hominids. The specimen was assigned at the time to Australopithecus and dated about four million years old. One method used to determine the age of the Kanapoi fossils was based on faunal correlation data, based on the limited postcranial evidence available, A. anamensis appears to have been habitually bipedal, although it retained some primitive features of its upper limbs. Leakey determined that this species was independent of many others and it does not represent an intermediate species of any type. Although the excavation team did not find hips, feet or legs, tree climbing was one behavior retained by early hominins until the appearance of the first Homo species about 2.5 million years ago. A. anamensis shares many traits with Australopithecus afarensis and may well be its direct predecessor. Fossil records for A. anamensis have been dated to between 4.2 and 3.9 million years ago, with recent findings from stratigraphic sequences dating to about 4. 1–4. 2 million years ago. Specimens have been found two layers of volcanic ash, dated to 4.17 and 4.12 million years. The fossils include upper and lower jaws, cranial fragments, in addition to this, the aforementioned fragment of humerus found thirty years ago at the same site at Kanapoi has now been assigned to this species. In 2006, a new A. anamensis find was officially announced, specifically, one site known as Asa Issie provided 30 A. anamensis fossils. These new fossils, sampled from a context, include the largest hominid canine tooth yet recovered. Ardipithecus was a primitive hominid, considered the next known step below Australopithecus on the evolutionary tree. Australopithecus anamensis was found in Kenya, specifically at Allia Bay, through analysis of stable isotope data, it is believed that their environment had more closed woodland canopies surrounding Lake Turkana than are present today. The greatest density of woodlands at Allia Bay was along the ancestral Omo River, there was believed to be more open savanna in the basin margins or uplands. Similarly at Allia Bay, it is suggested that the environment was much wetter, while it is not definitive, it also could have been possible that nut or seed-bearing trees could have been present at Allia Bay, however more research is needed
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Greek language
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Greek is an independent branch of the Indo-European family of languages, native to Greece and other parts of the Eastern Mediterranean. It has the longest documented history of any living language, spanning 34 centuries of written records and its writing system has been the Greek alphabet for the major part of its history, other systems, such as Linear B and the Cypriot syllabary, were used previously. The alphabet arose from the Phoenician script and was in turn the basis of the Latin, Cyrillic, Armenian, Coptic, Gothic and many other writing systems. Together with the Latin texts and traditions of the Roman world, during antiquity, Greek was a widely spoken lingua franca in the Mediterranean world and many places beyond. It would eventually become the official parlance of the Byzantine Empire, the language is spoken by at least 13.2 million people today in Greece, Cyprus, Italy, Albania, Turkey, and the Greek diaspora. Greek roots are used to coin new words for other languages, Greek. Greek has been spoken in the Balkan peninsula since around the 3rd millennium BC, the earliest written evidence is a Linear B clay tablet found in Messenia that dates to between 1450 and 1350 BC, making Greek the worlds oldest recorded living language. Among the Indo-European languages, its date of earliest written attestation is matched only by the now extinct Anatolian languages, the Greek language is conventionally divided into the following periods, Proto-Greek, the unrecorded but assumed last ancestor of all known varieties of Greek. The unity of Proto-Greek would have ended as Hellenic migrants entered the Greek peninsula sometime in the Neolithic era or the Bronze Age, Mycenaean Greek, the language of the Mycenaean civilisation. It is recorded in the Linear B script on tablets dating from the 15th century BC onwards, Ancient Greek, in its various dialects, the language of the Archaic and Classical periods of the ancient Greek civilisation. It was widely known throughout the Roman Empire, after the Roman conquest of Greece, an unofficial bilingualism of Greek and Latin was established in the city of Rome and Koine Greek became a first or second language in the Roman Empire. The origin of Christianity can also be traced through Koine Greek, Medieval Greek, also known as Byzantine Greek, the continuation of Koine Greek in Byzantine Greece, up to the demise of the Byzantine Empire in the 15th century. Much of the written Greek that was used as the language of the Byzantine Empire was an eclectic middle-ground variety based on the tradition of written Koine. Modern Greek, Stemming from Medieval Greek, Modern Greek usages can be traced in the Byzantine period and it is the language used by the modern Greeks, and, apart from Standard Modern Greek, there are several dialects of it. In the modern era, the Greek language entered a state of diglossia, the historical unity and continuing identity between the various stages of the Greek language is often emphasised. Greek speakers today still tend to regard literary works of ancient Greek as part of their own rather than a foreign language and it is also often stated that the historical changes have been relatively slight compared with some other languages. According to one estimation, Homeric Greek is probably closer to demotic than 12-century Middle English is to modern spoken English, Greek is spoken by about 13 million people, mainly in Greece, Albania and Cyprus, but also worldwide by the large Greek diaspora. Greek is the language of Greece, where it is spoken by almost the entire population
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Kenyanthropus
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Kenyanthropus platyops is a 3.5 to 3. 2-million-year-old hominin fossil discovered in Lake Turkana, Kenya in 1999 by Justus Erus, who was part of Meave Leakeys team. The species name “platyops” is derived from two Greek words, platus, which means flat, and opsis, which means face and this indicated that species were much more diverse in the distant past than previously thought. Even with the findings of a skull, their diet is still unknown at this time. Also, no evidence of culture or anything that would lead to its behavioral adaptations or lifestyle has been discovered at this time. Several aspects of the environment in which it may have lived have been proposed and it is believed that they lived in a “mosaic” environment, which had both grassland and some forested areas. In 1999, Meave Leakey led an expedition in Kenya to dig for fossils, the first expedition was in 1998 in which the paratype, KNM-WT38350 was discovered. They began to dig at a site that had yielded many other prominent hominin fossil specimens, Lake Turkana, a member of the team, Justus Erus, discovered a skull in the Nachukui Formation at Lomekwi, an area of specific geology right next to the lake. KNM-WT40000 and the bones were collected from a dark mudstone. The mudstone was located in between the Lokochot Tuff and the Tulu Bor Tuff in the Kataboi Member, beneath the Lokochot Tuff were the Moiti Tuff and the Topernawi Tuff. The KNM-WT40000 specimen was dated at 3.5 million years, directly beneath the bed was the KNM-WT38341 specimen, which was dated at 3.53 million years. Other specimens from various localities that were found above the b-Tulu Bor Tuff were dated at around 3.3 million years, the location of the mudstone was near a shallow lake, suggesting that the hominins lived near rivers or lakes. KNM-WT40000 is the holotype, the specimen of which the description, the fossils of Kenyanthropus platyops indicate that hominins were more taxonomically diverse during the middle Pliocene. The discovery of this fossil also dated non forward-projecting jaws further back than previous discoveries, the facial structure of the Kenyanthropus and its derived features were very different of that of the Paranthropus, including almost every cranial feature. This gave no reason to assign the new skull in the genus Paranthropus and it is still thought that the differences in cranial structure are too different for even that to be a possibility. The Kenyanthropus also shows many differences to Homo, as well as Ardipithecus, having smaller molars at the date they existed, it is possible that the previous sister taxon of all modern hominins, Preanthropus afarensis, should be replaced by Kenyanthropus. Fragmentary specimens which were having trouble being classified are now being assessed to see if they fit with the Kenyanthropus, the Kenyanthropus platyops was examined by Collard and Wood to have two types of characteristics categorized as craniometric and traditional. Craniometric characters represent size-adjusted linear measurements between standard cranial landmarks, traditional characters represent those most commonly used in systematic studies of apes and early hominids. These characters can be quantitative and qualitative, Kenyanthropus platyops was singled out by the morphology of the maxilla, characterized by a flat and relatively orthognathic subnasal region, an anteriorly placed zygomatic process and small molars
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Ardipithecus
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Ardipithecus is a genus of an extinct hominine that lived during Late Miocene and Early Pliocene in Afar Depression, Ethiopia. Two fossil species are described in the literature, A. ramidus, which lived about 4.4 million years ago during the early Pliocene, behavioral analysis showed that Ardipithecus could be very similar to chimpanzees, indicating that the early human ancestors were very chimpanzee-like in behaviour. A. ramidus was named in September 1994, the first fossil found was dated to 4.4 million years ago on the basis of its stratigraphic position between two volcanic strata, the basal Gaala Tuff Complex and the Daam Aatu Basaltic Tuff. The name Ardipithecus ramidus stems mostly from the Afar language, in which Ardi means ground/floor, the pithecus portion of the name is from the Greek word for ape. Like most hominids, but unlike all previously recognized hominins, it had a grasping hallux or big toe adapted for locomotion in the trees and it is not confirmed how much other features of its skeleton reflect adaptation to bipedalism on the ground as well. Like later hominins, Ardipithecus had reduced canine teeth, more fragments were recovered in 1994, amounting to 45% of the total skeleton. This fossil was described as a species of Australopithecus, but White. Between 1999 and 2003, a team led by Sileshi Semaw discovered bones. The fossils were dated to between 4.35 and 4.45 million years old, Ardipithecus ramidus had a small brain, measuring between 300 and 350 cm3. Like common chimpanzees, A. ramidus was much more prognathic than modern humans, the size of the upper canine tooth in A. ramidus males was not distinctly different from that of females. The features of the canine in A. ramidus contrast with the sexual dimorphism observed in common chimpanzees. The less pronounced nature of the canine teeth in A. ramidus has been used to infer aspects of the social behavior of the species. In particular, it has used to suggest that the last common ancestor of hominids. This is markedly different from social patterns in common chimpanzees, among which intermale, researchers in a 2009 study said that this condition compromises the living chimpanzee as a behavioral model for the ancestral hominid condition. A. ramidus existed more recently than the most recent common ancestor of humans and chimpanzees, nevertheless, it is in some ways unlike chimpanzees, suggesting that the common ancestor differs from the modern chimpanzee. After the chimpanzee and human lineages diverged, both underwent substantial evolutionary change, chimp feet are specialized for grasping trees, A. ramidus feet are better suited for walking. The canine teeth of A. ramidus are smaller, and equal in size between males and females, which suggests reduced male-to-male conflict, increased pair-bonding, and increased parental investment. Thus, fundamental reproductive and social behavioral changes probably occurred in long before they had enlarged brains and began to use stone tools
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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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Paleontology
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Paleontology or palaeontology is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene Epoch. It includes the study of fossils to determine organisms evolution and interactions with each other, paleontological observations have been documented as far back as the 5th century BC. The science became established in the 18th century as a result of Georges Cuviers work on comparative anatomy, and developed rapidly in the 19th century. The term itself originates from Greek παλαιός, palaios, i. e. old, ancient, ὄν, on, i. e. being, creature and λόγος, logos, i. e. speech, thought, study. Paleontology lies on the border between biology and geology, but differs from archaeology in that it excludes the study of modern humans. It now uses techniques drawn from a range of sciences, including biochemistry, mathematics. The final quarter of the 20th century saw the development of molecular phylogenetics, molecular phylogenetics has also been used to estimate the dates when species diverged, but there is controversy about the reliability of the molecular clock on which such estimates depend. The simplest definition is the study of ancient life, paleontology is one of the historical sciences, along with archaeology, geology, astronomy, cosmology, philology and history itself. This means that it aims to describe phenomena of the past, hence it has three main elements, description of the phenomena, developing a general theory about the causes of various types of change, and applying those theories to specific facts. Sometimes the smoking gun is discovered by an accident during other research. Paleontology lies on the boundary between biology and geology since paleontology focuses on the record of past life but its source of evidence is fossils. In addition paleontology often uses techniques derived from other sciences, including biology, osteology, ecology, chemistry, techniques developed in engineering have been used to analyse how ancient organisms might have worked, for example how fast Tyrannosaurus could move and how powerful its bite was. As knowledge has increased, paleontology has developed specialised subdivisions, vertebrate paleontology concentrates on fossils of vertebrates, from the earliest fish to the immediate ancestors of modern mammals. Invertebrate paleontology deals with fossils of such as molluscs, arthropods. Paleobotany focuses on the study of plants, but traditionally includes the study of fossil algae. Palynology, the study of pollen and spores produced by plants and protists. Micropaleontology deals with all microscopic fossil organisms, regardless of the group to which they belong, one example is the development of oxygenic photosynthesis by bacteria, which hugely increased the productivity and diversity of ecosystems. This also caused the oxygenation of the atmosphere, together, these were a prerequisite for the evolution of the most complex eukaryotic cells, from which all multicellular organisms are built
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Archaeology
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Archaeology, or archeology, is the study of human activity through the recovery and analysis of material culture. The archaeological record consists of artifacts, architecture, biofacts or ecofacts, Archaeology can be considered both a social science and a branch of the humanities. In North America, archaeology is considered a sub-field of anthropology, archaeologists study human prehistory and history, from the development of the first stone tools at Lomekwi in East Africa 3.3 million years ago up until recent decades. Archaeology as a field is distinct from the discipline of palaeontology, Archaeology is particularly important for learning about prehistoric societies, for whom there may be no written records to study. Prehistory includes over 99% of the human past, from the Paleolithic until the advent of literacy in societies across the world, Archaeology has various goals, which range from understanding culture history to reconstructing past lifeways to documenting and explaining changes in human societies through time. The discipline involves surveying, excavation and eventually analysis of data collected to learn more about the past, in broad scope, archaeology relies on cross-disciplinary research. Archaeology developed out of antiquarianism in Europe during the 19th century, Archaeology has been used by nation-states to create particular visions of the past. Nonetheless, today, archaeologists face many problems, such as dealing with pseudoarchaeology, the looting of artifacts, a lack of public interest, the science of archaeology grew out of the older multi-disciplinary study known as antiquarianism. Antiquarians studied history with attention to ancient artifacts and manuscripts. Tentative steps towards the systematization of archaeology as a science took place during the Enlightenment era in Europe in the 17th and 18th centuries, in Europe, philosophical interest in the remains of Greco-Roman civilization and the rediscovery of classical culture began in the late Middle Age. Antiquarians, including John Leland and William Camden, conducted surveys of the English countryside, one of the first sites to undergo archaeological excavation was Stonehenge and other megalithic monuments in England. John Aubrey was a pioneer archaeologist who recorded numerous megalithic and other monuments in southern England. He was also ahead of his time in the analysis of his findings and he attempted to chart the chronological stylistic evolution of handwriting, medieval architecture, costume, and shield-shapes. Excavations were also carried out in the ancient towns of Pompeii and Herculaneum and these excavations began in 1748 in Pompeii, while in Herculaneum they began in 1738. The discovery of entire towns, complete with utensils and even human shapes, however, prior to the development of modern techniques, excavations tended to be haphazard, the importance of concepts such as stratification and context were overlooked. The father of archaeological excavation was William Cunnington and he undertook excavations in Wiltshire from around 1798, funded by Sir Richard Colt Hoare. Cunnington made meticulous recordings of neolithic and Bronze Age barrows, one of the major achievements of 19th century archaeology was the development of stratigraphy. The idea of overlapping strata tracing back to successive periods was borrowed from the new geological and paleontological work of scholars like William Smith, James Hutton, the application of stratigraphy to archaeology first took place with the excavations of prehistorical and Bronze Age sites
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Human evolution
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Human evolution from its first separation from the last common ancestor of humans and chimpanzees is characterized by a number of morphological, developmental, physiological, and behavioral changes. The most significant of these adaptations are bipedalism, increased size, lengthened ontogeny. The relationship between these changes is the subject of ongoing debate, other significant morphological changes included the evolution of a power and precision grip, a change first occurring in H. erectus. Bipedalism is the adaptation of the hominin and is considered the main cause behind a suite of skeletal changes shared by all bipedal hominins. The earliest hominin, of presumably primitive bipedalism, is considered to be either Sahelanthropus or Orrorin, Ardipithecus, a full biped, arose somewhat later. The early bipeds eventually evolved into the australopithecines and still later into the genus Homo, There are several theories of the adaptation value of bipedalism. A new study provides support for the hypothesis that walking on two legs, or bipedalism, evolved because it used less energy than quadrupedal knuckle-walking, however, recent studies suggest that bipedality without the ability to use fire would not have allowed global dispersal. This change in gait saw a lengthening of the legs proportionately when compared to the length of the arms, another change is the shape of the big toe. Recent studies suggest that Australopithecines still lived part of the time in trees as a result of maintaining a big toe. This was progressively lost in Habilines, anatomically, the evolution of bipedalism has been accompanied by a large number of skeletal changes, not just to the legs and pelvis, but also to the vertebral column, feet and ankles, and skull. The femur evolved into a more angular position to move the center of gravity toward the geometric center of the body. The knee and ankle joints became increasingly robust to support increased weight. To support the weight on each vertebra in the upright position, the human vertebral column became S-shaped. In the feet the big toe moved into alignment with the toes to help in forward locomotion. The arms and forearms shortened relative to the making it easier to run. The foramen magnum migrated under the skull and more anterior, during human birth, because of the variation in size of the pelvic region, the fetal head must be in a transverse position during entry into the birth canal and rotate about 90 degrees upon exit. The human species developed a much larger brain than that of other primates—typically 1,330 cm3 in modern humans. This pattern of brain increase happened through the pattern of human postnatal brain growth differs from that of other apes
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