1.
North American beaver
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The North American beaver is one of two extant beaver species. It is native to North America and introduced to Patagonia in South America, other vernacular names, including American beaver and Canadian beaver, distinguish this species from the other extant beaver species, Castor fiber, which is native to Eurasia. The North American beaver is an animal symbol of Canada. Adults usually weigh from 11 to 32 kg, with 20 kg being typical, the head-and-body length is 74–90 cm, with the tail adding a further 20–35 cm. Very old individuals can exceed normal sizes, weighing more than 40 kg or even as much as 50 kg. Like the capybara, the beaver is semiaquatic, the beaver has many traits suited to this lifestyle. It has a large, flat, paddle-shaped tail and large, the unwebbed front paws are smaller, with claws. The eyes are covered by a membrane which allows the beaver to see under water. The nostrils and ears are sealed while submerged, a thick layer of fat under its skin insulates the beaver from its coldwater environment. The beavers fur consists of long, coarse hairs and short. The fur has a range of colours, but usually is dark brown, scent glands near the genitals secrete an oily substance known as castoreum, which the beaver uses to waterproof its fur. Physician naturalist Edgar Alexander Mearns 1907 report of beaver on the Sonora River may be the southernmost extent of the range of this North American aquatic mammal. However, beavers have also been reported both historically and contemporaneously in Mexico on the Colorado River, Bavispe River, and San Bernardino River, beavers are active mainly at night. They are excellent swimmers and may remain submerged up to 15 minutes, more vulnerable on land, they tend to remain in the water as much as possible. They use their flat, scaly tail both to signal danger by slapping the surface of the water and as a location for fat storage. They construct their homes, or lodges, out of sticks, twigs, rocks, and mud in lakes, streams and these lodges may be surrounded by water, or touching land, including burrows dug into river banks. Beavers are well known for building dams across streams and constructing their lodges in the ponds which form. When building in a pond, the beavers first make a pile of sticks and then eat out one or more underwater entrances, the first is used for drying off
2.
Eurasian beaver
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The Eurasian beaver or European beaver is a species of beaver which was once widespread in Eurasia. It was hunted to near-extinction for both its fur and castoreum, and by 1900, only 1200 beavers survived in eight relict populations in Europe and Asia. Reintroduced through much of its range, it now occurs from Great Britain to China and Mongolia, although it is absent from Italy, Portugal, the southern Balkans. The fur color of Eurasian beavers varies geographically, light, chestnut-rust is the dominant colour in Belarus. In Russia, the beavers of the Sozh River basin are predominantly blackish brown, Eurasian beavers are one of the largest living species of rodents and are the largest rodent native to Eurasia. They weigh around 11–30 kg, with an average of 18 kg, while the largest specimen confirmed on record weighed 31.7 kg, the Smithsonian has reported that this species can exceptionally exceed 40 kg. Typically, the length is 80–100 cm and the tail length is 25–50 cm. The Eurasian beaver also has nasal bones, with the widest point being at the end of the snout, in the case of the North American beaver. The Eurasian beaver has a triangular opening, unlike those of the North American beavers. Furthermore, the foramen magnum is rounded in the Eurasian beaver, the anal glands of the Eurasian beaver are larger, and thin-walled, with a large internal volume, relative to that of the North American beaver. The guard hairs of the Eurasian beaver have longer hollow medullae at their tips, the two species are not genetically compatible. The North American beaver has 40 chromosomes, while the Eurasian beaver has 48, after more than 27 attempts in Russia to hybridize the two species, the result was one stillborn kit that was bred from the pairing of a male North American beaver and a female Eurasian beaver. The aforementioned factor makes interspecific breeding unlikely in areas where the two species ranges overlap, historically, eight subspecies of Castor fiber were described, one for each of the eight 19th– to 20th-century refugia where the species never became extinct. The basis of the differentiation was morphological, largely based on small differences in cranial morphology. In 2005, Durka et al. showed that only two evolutionarily significant units exist based on mitochondrial DNA studies, a western phylogroup and an eastern phylogroup. Eurasian beavers have one litter per year, coming into estrus for only 12 to 24 hours, unlike most other rodents, beaver pairs are monogamous, staying together for multiple breeding seasons. Gestation averages 107 days and they average three kits per litter with a range of two to six kits, most beavers do not reproduce until they are three years of age, but about 20% of two-year-old females reproduce. The Eurasian beaver is recovering from near extinction, after depredation by humans for its fur and for castoreum, the estimated population was only 1,200 by the early 20th century
3.
Mountain beaver
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The mountain beaver is a North American rodent. It has several names, including, aplodontia, mountain boomer, ground bear. The name sewellel beaver comes from sewellel or suwellel, the Chinookan term for a made from its pelts. This species is the only living member of its genus, Aplodontia and it should not be confused with true North American and Eurasian beavers, to which it is not closely related. Mountain beavers are brown, but their fur can range from slightly more reddish to more blackish depending on subspecies, the animals have distinctively short tails. Adults weigh about 500–900 g, with a few specimens topping 1,000 g, total length is about 30–50 cm, with a tail length of 1–4 cm. The skull is protrogomorphous, it has no specialized attachments for the muscles as seen in other rodents. It is flattened and lacks a postorbital process, the baculum is thin and distinctly forked. The penis is about 4.5 cm in length, the male does not have a true scrotum, but the testes move into a position called semiscrotal during the breeding season. Mountain beavers have a projection on each molar and premolar tooth. This projection points toward the cheek on the tooth row. The cheek teeth lack the complex folds of other rodents and instead consist of single basins. Two upper and one lower premolars are present, along all the molars. Their karyotype is 2n =46 and they range from sea level to the tree line. They can be found in deciduous and coniferous forests, but throughout most of the range appear to prefer the former. These animals appear to be limited to moist microenvironments, with most subspecies occurring only in regions with minimal snowfall. They do not appear to be able to body heat or warmth as efficiently as other rodents. They exhibit coprophagy and eat soft fecal pellets to obtain maximum nutrients, food includes fleshy herbs and young shoots of more woody plants
4.
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
5.
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
6.
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
7.
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
8.
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
9.
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
10.
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
11.
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
12.
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
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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
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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
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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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Miocene
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The Miocene is the first geological epoch of the Neogene Period and extends from about 23.03 to 5.333 million years ago. The Miocene was named by Sir Charles Lyell and its name comes from the Greek words μείων and καινός and means less recent because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene Epoch and is followed by the Pliocene Epoch, the earth went from the Oligocene through the Miocene and into the Pliocene, with the climate slowly cooling towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event, the apes arose and diversified during the Miocene, becoming widespread in the Old World. By the end of this epoch, the ancestors of humans had split away from the ancestors of the chimpanzees to follow their own evolutionary path, as in the Oligocene before it, grasslands continued to expand and forests to dwindle in extent. In the Miocene seas, kelp forests made their first appearance, the plants and animals of the Miocene were fairly modern. The Miocene faunal stages from youngest to oldest are typically named according to the International Commission on Stratigraphy, Two subdivisions each form the lower, middle, continents continued to drift toward their present positions. Mountain building took place in western North America, Europe, both continental and marine Miocene deposits are common worldwide with marine outcrops common near modern shorelines. Well studied continental exposures occur in the North American Great Plains, India continued to collide with Asia, creating dramatic new mountain ranges. The Tethys Seaway continued to shrink and then disappeared as Africa collided with Eurasia in the Turkish–Arabian region between 19 and 12 Ma. The subsequent uplift of mountains in the western Mediterranean region and a fall in sea levels combined to cause a temporary drying up of the Mediterranean Sea near the end of the Miocene. The global trend was towards increasing aridity caused primarily by global cooling reducing the ability of the atmosphere to absorb moisture, climates remained moderately warm, although the slow global cooling that eventually led to the Pleistocene glaciations continued. Although a long-term cooling trend was well underway, there is evidence of a period during the Miocene when the global climate rivalled that of the Oligocene. The Miocene warming began 21 million years ago and continued until 14 million years ago, by 8 million years ago, temperatures dropped sharply once again, and the Antarctic ice sheet was already approaching its present-day size and thickness. Greenland may have begun to have large glaciers as early as 7 to 8 million years ago, life during the Miocene Epoch was mostly supported by the two newly formed biomes, kelp forests and grasslands. This allows for more grazers, such as horses, rhinoceroses, ninety five percent of modern plants existed by the end of this epoch. The higher organic content and water retention of the deeper and richer grassland soils, with long term burial of carbon in sediments, produced a carbon and this, combined with higher surface albedo and lower evapotranspiration of grassland, contributed to a cooler, drier climate. The expansion of grasslands and radiations among terrestrial herbivores correlates to fluctuations in CO2
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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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Rodent
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Rodents are mammals of the order Rodentia, which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all species are rodents, they are found in vast numbers on all continents except Antarctica. They are the most diversified mammalian order and live in a variety of terrestrial habitats, Species can be arboreal, fossorial, or semiaquatic. Well-known rodents include mice, rats, squirrels, prairie dogs, porcupines, beavers, guinea pigs, hamsters, and capybaras. Other animals such as rabbits, hares, and pikas, whose incisors also grow continually, were included with them, but are now considered to be in a separate order. Nonetheless, Rodentia and Lagomorpha are sister groups, sharing a most recent common ancestor, most rodents are small animals with robust bodies, short limbs, and long tails. They use their incisors to gnaw food, excavate burrows. Most eat seeds or other plant material, but some have more varied diets and they tend to be social animals and many species live in societies with complex ways of communicating with each other. Mating among rodents can vary from monogamy, to polygyny, to promiscuity, many have litters of underdeveloped, altricial young, while others are precocial at birth. The rodent fossil record back to the Paleocene on the supercontinent of Laurasia. Rodents greatly diversified in the Eocene, as spread across continents. Rodents reached both South America and Madagascar from Africa, and were the only placental mammals to reach. Rodents have been used as food, for clothing, as pets, some species, in particular the brown rat, the black rat, and the house mouse, are serious pests, eating and spoiling food stored by humans, and spreading diseases. The distinguishing feature of the rodents is their pairs of continuously growing and these incisors have thick layers of enamel on the front and little enamel on the back. Because they do not stop growing, the animal must continue to wear them down so that they do not reach and pierce the skull. As the incisors grind against each other, the softer dentine on the rear of the teeth wears away, most species have up to 22 teeth with no canines or anterior premolars. A gap, or diastema, occurs between the incisors and the teeth in most species. This allows rodents to suck in their cheeks or lips to shield their mouth and throat from wood shavings and other inedible material, chinchillas and guinea pigs have a high-fiber diet, their molars have no roots and grow continuously like their incisors
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Castoridae
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The family Castoridae contains the two living species of beavers and their fossil relatives. This was once a diverse group of rodents, but is now restricted to a single genus. Castorids are medium-sized mammals, although compared with most other rodents. They are semiaquatic, with bodies and webbed hind feet. Their tails are flattened and scaly, adaptations that help them manoeuvre in the water, castorids live in small family groups that each occupy a specific territory, based around a lodge and dam constructed from sticks and mud. They are herbivores, feeding on leaves and grasses in the summer and they have powerful incisors and the typical rodent dental formula, The earliest castorids belong to the genus Agnotocastor, known from the late Eocene and Oligocene of North America and Asia. Their teeth were not well suited to gnawing wood, suggesting this habit evolved at a later point, later, such early species evolved into forms such as Palaeocastor from the Miocene of Nebraska. Palaeocastor was about the size of a muskrat, and dug corkscrew-shaped burrows up to 2.5 m deep, giant forms evolved in the Pleistocene, including Trogontherium in Europe, and Castoroides in North America. The latter animal was as large as a bear, yet had a brain only marginally larger than that of modern beavers. Its shape suggests it would have been a swimmer. McKenna and Bell divided Castoridae into two subfamilies, Castoroidinae and Castorinae, more recent studies have recognized two additional subfamilies of basal castorids, Agnotocastorinae and Palaeocastorinae, which is followed here. Within the family, Castorinae and Castoroidinae are sister taxa, they share a more recent common ancestor with other than with members of the other two subfamilies. Both subfamilies include semiaquatic species capable of constructing dams, the Palaeocastorinae include beavers that are interpreted as fossorial, as are nothodipoidins and Migmacastor. The following taxonomy is based on Korth and Rybczynski, with preference given to the latter where these differ
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Carl Linnaeus
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Carl Linnaeus, also known after his ennoblement as Carl von Linné, was a Swedish botanist, physician, and zoologist, who formalised the modern system of naming organisms called binomial nomenclature. He is known by the father of modern taxonomy. Many of his writings were in Latin, and his name is rendered in Latin as Carolus Linnæus, Linnaeus was born in the countryside of Småland, in southern Sweden. He received most of his education at Uppsala University. He lived abroad between 1735 and 1738, where he studied and also published a first edition of his Systema Naturae in the Netherlands and he then returned to Sweden, where he became professor of medicine and botany at Uppsala. In the 1740s, he was sent on journeys through Sweden to find and classify plants. In the 1750s and 1760s, he continued to collect and classify animals, plants, and minerals, at the time of his death, he was one of the most acclaimed scientists in Europe. The philosopher Jean-Jacques Rousseau sent him the message, Tell him I know no man on earth. The German writer Johann Wolfgang von Goethe wrote, With the exception of Shakespeare and Spinoza, Swedish author August Strindberg wrote, Linnaeus was in reality a poet who happened to become a naturalist. Among other compliments, Linnaeus has been called Princeps botanicorum, The Pliny of the North and he is also considered as one of the founders of modern ecology. In botany, the abbreviation used to indicate Linnaeus as the authority for species names is L. In older publications, sometimes the abbreviation Linn. is found, Linnæus was born in the village of Råshult in Småland, Sweden, on 23 May 1707. He was the first child of Nicolaus Ingemarsson and Christina Brodersonia and his siblings were Anna Maria Linnæa, Sofia Juliana Linnæa, Samuel Linnæus, and Emerentia Linnæa. One of a line of peasants and priests, Nils was an amateur botanist, a Lutheran minister. Christina was the daughter of the rector of Stenbrohult, Samuel Brodersonius, a year after Linnæus birth, his grandfather Samuel Brodersonius died, and his father Nils became the rector of Stenbrohult. The family moved into the rectory from the curates house, even in his early years, Linnæus seemed to have a liking for plants, flowers in particular. Whenever he was upset, he was given a flower, which calmed him. Nils spent much time in his garden and often showed flowers to Linnaeus, soon Linnæus was given his own patch of earth where he could grow plants
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10th edition of Systema Naturae
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The 10th edition of Systema Naturae is a book written by Carl Linnaeus and published in two volumes in 1758 and 1759, which marks the starting point of zoological nomenclature. In it, Linnaeus introduced binomial nomenclature for animals, something he had already done for plants in his 1753 publication of Species Plantarum, before 1758, most biological catalogues had used polynomial names for the taxa included, including earlier editions of Systema Naturae. The first work to consistently apply binomial nomenclature across the kingdom was the 10th edition of Systema Naturae. Names published before that date are unavailable, even if they would otherwise satisfy the rules, during Linnaeus lifetime, Systema Naturae was under continuous revision. The Animal Kingdom, Animals enjoy sensation by means of an organization, animated by a medullary substance, perception by nerves. They have members for the different purposes of life, organs for their different senses and they all originate from an egg. Their external and internal structure, their anatomy, habits, instincts. The list has been broken down into the six classes Linnaeus described for animals, Mammalia, Aves, Amphibia, Pisces, Insecta. These classes were created by studying the internal anatomy, as seen in his key. Warm, red blood Viviparous, Mammalia Oviparous, Aves Heart with 1 auricle,1 ventricle, cold, red blood Lungs voluntary, Amphibia External gills, Pisces Heart with 1 auricle,0 ventricles. Linnaeus described mammals as, Animals that suckle their young by means of lactiferous teats, in external and internal structure they resemble man, most of them are quadrupeds, and with man, their natural enemy, inhabit the surface of the Earth. The largest, though fewest in number, inhabit the ocean and they are areal, vocal, swift and light, and destitute of external ears, lips, teeth, scrotum, womb, bladder, epiglottis, corpus callosum and its arch, and diaphragm. They breathe by means of gills, which are united by a bony arch, swim by means of radiate fins. Many of them are without a head, and most of them without feet. They are principally distinguished by their tentacles, by the Ancients they were not improperly called imperfect animals, as being destitute of ears, nose, head, eyes and legs, and are therefore totally distinct from Insects. In addition to repeating the species he had listed in his Species Plantarum. The species from Species Plantarum were numbered sequentially, while the new species were labelled with letters, new plant species described in the 10th edition of Systema Naturae include, The original 1758 Systema Naturae Linnaeus 1758 Classification of Animals on the Taxonomicon
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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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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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Nocturnality
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Nocturnality is an animal behavior characterized by activity during the night and sleeping during the day. The common adjective is nocturnal, versus diurnal meaning the opposite, nocturnal creatures generally have highly developed senses of hearing, smell, and specially adapted eyesight. Such traits can help such as the Helicoverpa zea moths avoid predators. Some animals, such as cats and ferrets, have eyes that can adapt to both lowlevel and bright day levels of illumination, others, such as bushbabies and bats, can function only at night. Many nocturnal creatures including tarsiers and some owls have large eyes in comparison to their size to compensate for the lower light levels at night. More specifically, they have found to have a larger cornea relative to their eye size than diurnal creatures to increase their visual sensitivity in the low-light conditions. Nocturnality helps wasps, such as Apoica flavissima, avoid hunting in intense sunlight, diurnal animals, including squirrels and songbirds, are active during the daytime. Crepuscular species, such as rabbits, skunks, cats, tigers, cathemeral species, such as fossas and lions, are active both in the day and at night. While most humans are diurnal, for personal and social/cultural reasons some people are temporarily or habitually nocturnal. The most known creatures to be nocturnal include cats, rodents, and owls, while it is difficult to say which came first, nocturnality or diurnality, there is a leading hypothesis out in the evolutionary biology community. A recent study attempts to answer the question as to why so many modern day mammals retain these nocturnal characteristics even though they are not active at night, the anomaly to this theory were anthropoids, who appeared to have the most divergence from nocturnality than all organisms examined. While most mammals didnt exhibit the characteristics expected of a nocturnal creature, reptiles. A larger cornea and pupil correlated well with whether these two classes of organisms were nocturnal or not, being active at night is a form of niche differentiation, where a species niche is partitioned not by the amount of resources but by the amount of time. Hawks and owls can hunt the same field or meadow for the same rodents without conflict because hawks are diurnal and this means they are not in competition for each others prey. Nocturnality is a form of crypsis, an adaptation to avoid or enhance predation, one of the reasons that lions prefer to hunt at night is that many of their prey species have poor night vision. Many species of rodents, such as the Large Japanese Field Mouse, are active at night because most of the dozen or so birds of prey that hunt them are diurnal. There are many species that exhibit some nocturnal behaviors. For example, many seabirds and sea turtles only gather at breeding sites or colonies at night to reduce the risk of predation to themselves and/or their offspring, another reason for nocturnality is avoiding the heat of the day
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Eurasia
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Eurasia /jʊˈreɪʒə/ is a combined continental landmass of Europe and Asia. The term is a portmanteau of its constituent continents, in geology, Eurasia is often considered as a single rigid megablock. However, the rigidity of Eurasia is debated based on the paleomagnet data, Eurasia covers around 55,000,000 square kilometres, or around 36. 2% of the Earths total land area. The landmass contains around 5.0 billion people, equating to approximately 70% of the human population, humans first settled in Eurasia between 60,000 and 125,000 years ago. Physiographically, Eurasia is a single continent, the concepts of Europe and Asia as distinct continents date back to antiquity and their borders are geologically arbitrary. Eurasia is connected to Africa at the Suez Canal, and Eurasia is sometimes combined with Africa as the largest contiguous landmass on Earth called Afro-Eurasia. Eurasia formed 375 to 325 million years ago with the merging of Siberia, Kazakhstania, and Baltica, chinese cratons collided with Siberias southern coast. Eurasia has been the host of ancient civilizations, including those based in Mesopotamia. In the Axial Age, a belt of civilizations stretched through the Eurasian subtropical zone from the Atlantic to the Pacific. This belt became the mainstream of world history for two millennia, originally, “Eurasia” is a geographical notion, in this sense, it is simply the biggest continent, the combined landmass of Europe and Asia. However, geopolitically, the word has different meanings, reflecting the specific geopolitical interests of each nation. “Eurasia” is one of the most important geopolitical concepts, as Zbigniew Brzezinski observed, how America manages Eurasia is critical. A power that dominates “Eurasia” would control two of the three most advanced and economically productive regions. About 75 per cent of the people live in “Eurasia”. “Eurasia” accounts for about three-fourths of the known energy resources. ”At the moment one of the most prominent projects of the European Union is the Russia - EU Four Common Spaces Initiative. A political and economic union of former Soviet states named the Eurasian Economic Union was established in 2015, the Russian concept of “Eurasia” corresponded initially more or less to the land area of Imperial Russia in 1914, including parts of Eastern Europe. One of Russias main geopolitical interests lies in ever closer integration with those countries that it considers part of “Eurasia. ”Every two years since 1996 a meeting of most Asian and European countries is organised as the Asia-Europe Meeting. In ancient times, the Greeks classified Europe and Asia as separate lands, where to draw the dividing line between the two regions is still a matter of discussion
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Capybara
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The capybara is the largest rodent in the world. It is a member of the genus Hydrochoerus, of which the other extant member is the lesser capybara. Close relatives are guinea pigs and rock cavies, and it is distantly related to the agouti, chinchillas. Native to South America, the capybara inhabits savannas and dense forests and it is a highly social species and can be found in groups as large as 100 individuals, but usually lives in groups of 10–20 individuals. The capybara is not a species and is hunted for its meat and hide. Its common name is derived from Tupi kaapiûara, a complex agglutination of kaá + píi + ú + ara, meaning one who eats slender leaves, the scientific name, both hydrochoerus and hydrochaeris, comes from Greek ὕδρω + χοίρος. The capybara and the lesser capybara belong to the subfamily Hydrochoerinae along with the rock cavies, the living capybaras and their extinct relatives were previously classified in their own family Hydrochoeridae. Since 2002, molecular studies have recognized a close relationship between Hydrochoerus and Kerodon supporting placement of both genera in a subfamily of Caviidae. The taxonomy of fossil hydrochoerines is also in a state of flux, in recent years, the diversity of fossil hydrochoerines has been substantially reduced. This is largely due to the recognition that capybara molar teeth show strong variation in shape over the life of an individual, the capybara has a heavy, barrel-shaped body and short head, with reddish-brown fur on the upper part of its body that turns yellowish-brown underneath. Its sweat glands can be found in the surface of the portions of its skin. The animal lacks under hair, and guard hair differs little from over hair. Adult capybaras grow to 106 to 134 cm in length, stand 50 to 62 cm tall at the withers, the top recorded weights are 91 kg for a wild female from Brazil and 73.5 kg for a wild male from Uruguay. Capybaras have slightly webbed feet and vestigial tails and their hind legs are slightly longer than their forelegs, they have three toes on their rear feet and four toes on their front feet. Their muzzles are blunt, with nostrils, and the eyes, females are slightly heavier than males. Its karyotype has 2n =66 and FN =102, capybaras are semiaquatic mammals found throughout almost all countries of South America except Chile. They live in forested areas near bodies of water, such as lakes, rivers, swamps, ponds. Capybara have flourished in cattle ranches and they roam in home ranges averaging 10 hectares in high-density populations
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Gopher
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Pocket gophers, commonly referred to as gophers, are burrowing rodents of the family Geomyidae. About 35 species of live in Central and North America. They are commonly known for their extensive tunneling activities, Gophers are endemic to North and Central America. The name pocket gopher on its own may be used to refer to any of a number of genera within the family and these are the true gophers, however several ground squirrels in the distantly related family Sciuridae are often called gophers, as well. The origin of the word gopher is uncertain, french gaufre, meaning waffle, has been suggested, on account of the gophers tunnels resembling the honeycomb-like pattern of holes in a waffle. Another suggestion is that the word is of Muskogean origin, Gophers weigh around 0.5 lb, and are about 6–8 in long in body length, with a tail 1–2 in long. A few species reach weights approaching 1 kg, within any species, the males are larger than the females and can be nearly double their weight. Their lifespans are normally one to three years assuming no diseases or predation, the maximum lifespan for the pocket gopher is about five years. Some gophers, such as those in the genus Geomys, have lifespans that have been documented as up to seven years in the wild, most gophers have brown fur that often closely matches the color of the soil in which they live. Their most characteristic features are their large cheek pouches, from which the pocket in their name derives. These pouches are fur-lined, can be turned out. Gophers have small eyes and a short, hairy tail, which use to feel around tunnels when they walk backwards. Pocket gophers have been found to carry external parasites. Common predators of the gopher include weasels, snakes, and hawks, all pocket gophers create a network of tunnel systems that provide protection and a means of collecting food. They are larder hoarders, and their cheek pouches are used for transporting back to their burrows. Unlike ground squirrels, gophers do not live in large communities, tunnel entrances can be identified by small piles of loose soil covering the opening. Their burrows can be found in areas where the soil is softer. They often appear in gardens, lawns, or farms
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Heteromyidae
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Heteromyidae is a family of rodents consisting of kangaroo rats, kangaroo mice, pocket mice and spiny pocket mice. They feed mostly on seeds and other plant parts, which they carry in their cheek pouches to their burrows. Although they are different in physical appearance, the closest relatives of the heteromyids are pocket gophers in the family Geomyidae. There are about fifty-nine members of the family Heteromyidae divided among six genera and they are all small rodents, the largest being the giant kangaroo rat with a body length of 15 cm and a tail a little longer than this. In many species the tail is tufted and is used for balance. Other adaptations include partially fused vertebrae in the neck, short fore limbs, the skulls vary widely across the group but they are all thin and papery and do not have the robust cranial crests and ridges found on the skulls of members of the family Geomyidae. The dental formula is 1/1, 0/0, 1/1, 3/3 making twenty teeth in total, in the kangaroo rats, the teeth continue to grow all the time, being worn away as the animal chews. The upper incisors are grooved and the enamel on the molars is quickly worn away by chewing leaving the dentine exposed, in the kangaroo rats they are unrooted but in the pocket mice they have roots. Fur-lined cheek pouches are a feature across the family Heteromyidae and they have openings near the mouth and extend backwards along the sides of the neck. The fur on the body is in general short and fine and often matches in colour the soil of the region in which the animal lives, being some shade of buff. The spiny pocket mice have coarser fur and spiky bristles on the back near the tail, heteromyids are endemic to the western United States, Mexico, Central America and northwestern South America. During the Oligocene, the extent of arid lands across the United States was greater than it is today, fossils of kangaroo rats are known from the Pliocene. The kangaroo rats, kangaroo mice and pocket mice are adapted for life in deserts, kangaroo rats have no need to drink because they are able to extract sufficient water from metabolising their food, obtaining half a gram of water from each gram of seeds eaten. They carry most of the seeds they find back to their burrows in exterior cheek folds lined with fur rather than in cheek pouches inside the mouth as do hamsters. This is because carrying the food in the mouth would involve wetting it, most species store the seeds they gather in special chambers in the burrow where they absorb moisture from the humid air. Others, such as Merriams kangaroo rat, bury them in caches in the open air. It has been found there is little hoarding done in the winter but that food is most commonly stored in the autumn. Heteromyds use sight and olfactory clues to locate food and then use their fore-feet to manipulate objects
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Castorimorpha
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Castorimorpha is the suborder of rodents containing the beavers, the pocket gophers, and the kangaroo rats and mice. Carleton, M. D. and G. G. Musser, pp 745-752 in Mammal Species of the World A Taxonomic and Geographic Reference. McKenna, Malcolm C. and Bell, Susan K.1997, classification of Mammals Above the Species Level. Columbia University Press, New York,631 pp. ISBN 0-231-11013-8
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Eocene
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The Eocene Epoch, lasting from 56 to 33.9 million years ago, is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a period in which the concentration of the carbon isotope 13C in the atmosphere was exceptionally low in comparison with the more common isotope 12C. As with other periods, the strata that define the start and end of the epoch are well identified. The name Eocene comes from the Ancient Greek ἠώς and καινός, the Eocene epoch is conventionally divided into early, middle, and late subdivisions. The corresponding rocks are referred to as lower, middle, the Ypresian stage constitutes the lower, the Priabonian stage the upper, and the Lutetian and Bartonian stages are united as the middle Eocene. The Eocene Epoch contained a variety of different climate conditions that includes the warmest climate in the Cenozoic Era. During this period of time, little to no ice was present on Earth with a difference in temperature from the equator to the poles. Following the maximum was a descent into an icehouse climate from the Eocene Optimum to the Eocene-Oligocene transition at 34 million years ago. During this decrease ice began to reappear at the poles, greenhouse gases, in particular carbon dioxide and methane, played a significant role during the Eocene in controlling the surface temperature. For the early Eocene there is discussion on how much carbon dioxide was in the atmosphere. This is due to numerous proxies representing different atmospheric carbon dioxide content, for contrast, today the carbon dioxide levels are at 400 ppm or 0. 04%. At about the beginning of the Eocene Epoch the amount of oxygen in the atmosphere more or less doubled. During the early Eocene, methane was another gas that had a drastic effect on the climate. In comparison to carbon dioxide, methane has much effect on temperature as methane is ~34 times more effective per molecule than carbon dioxide on a 100-year scale. Most of the methane released to the atmosphere during this period of time would have been from wetlands, swamps, the atmospheric methane concentration today is 0. 000179% or 1.79 ppmv. Due to the climate and sea level rise associated with the early Eocene, more wetlands, more forests. Comparing the early Eocene production of methane to current levels of atmospheric methane, biogenic production of methane produces carbon dioxide and water vapor along with the methane, as well as yielding infrared radiation
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Castoroides
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Castoroides, or giant beaver, is an extinct genus of enormous beavers that lived in North America during the Pleistocene. C. leiseyorum and its sister species Castoroides ohioensis, were the largest beavers to ever exist. Species of Castoroides, also known as giant beavers, were larger than modern beavers. Their average length was approximately 1.9 m, and they could grow as large as 2.2 m, the weight of the giant beaver could vary from 90 kg to 125 kg. This makes it the largest known rodent in North America during the Pleistocene, the hind feet of the giant beaver were much larger than in modern beavers, while the hind legs were shorter. The tail was longer but may have been narrower, however, because soft tissues decay, it is not known whether its tail resembled the tails in modern beavers, and it can only be assumed that its feet were webbed like in modern species. The skull structure of the giant beaver shows that it participated in extended underwater activity. One of the characteristics of the giant beaver were their incisors. Modern beavers have chisel-like incisor teeth for gnawing on wood, while the teeth of the giant beaver were bigger and broader and these incisors were not as efficient at cutting wood, therefore it is possible that the giant beaver did not construct dams. One other major difference between the giant beaver and the beaver is that the size of its brain was proportionally smaller. As a result, giant beavers may have had inferior interactions in its environment as well as less complex patterns of thoughts, there are two known species, Castoroides leiseyorum Castoroides ohioensis, synonym Castoroides nebrascensis These two species of giant beaver are not close relatives to modern beavers. The Castoroides fossils were discovered in 1837 in a bog in Ohio. Castoroides had cutting teeth up to 15 cm-long with prominently-ridged outer surfaces and these strong enamel ridges would have acted as girders to support such long teeth. Further, the deep masseteric fossa of the jaw suggests a very powerful bite. Perhaps their teeth could have acted as both wood-cutters and gouges, there is no clear evidence that the giant beaver felled trees or built dams, but a possible lodge was discovered near New Knoxville, Ohio around 1912. Part of a giant beaver skull and the lodge were located in a peaty layer surrounded by loam, in Ohio, there have been claims of a possible giant beaver lodge four feet high and eight feet in diameter, formed from small saplings. The recent discovery of evidence for lodge building in the related genus Dipoides indicates that the giant beaver probably also built lodges. In Canada, fossils of species are commonly found in the Old Crow Basin, Yukon
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Populus tremuloides
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Populus tremuloides is a deciduous tree native to cooler areas of North America, one of several species referred to by the common name aspen. It is commonly called quaking aspen, trembling aspen, American aspen, Quakies, mountain or golden aspen, trembling poplar, white poplar, popple, the trees have tall trunks, up to 25 meters tall, with smooth pale bark, scarred with black. The glossy green leaves, dull beneath, become golden to yellow, rarely red, the species often propagates through its roots to form large groves originating from a shared system of rhizomes. Populus tremuloides is the most widely distributed tree in North America and it is the defining species of the aspen parkland biome in the Prairie Provinces of Canada and extreme northwest Minnesota. The quaking or trembling of the leaves that is referred to in the names is due to the flexible flattened petioles. The specific epithet, tremuloides, evokes this trembling behavior and can be translated as like tremula. Some species of Populus have petioles flattened partially along their length, while the aspens and some other poplars have them flattened from side to side along the entire length of the petiole. Quaking aspen is a tall, fast growing tree, usually 20–25 m at maturity, with a trunk 20 to 80 cm in diameter, the bark is relatively smooth, colored greenish-white to gray, and is marked by thick black horizontal scars and prominent black knots. Parallel vertical scars are tell-tale signs of elk, which strip off bark with their front teeth. The leaves on trees are nearly round, 4–8 centimeters in diameter with small rounded teeth. Young trees and root sprouts have much larger nearly triangular leaves, aspens are dioecious, with separate male and female clones. The quaking aspen is the State Tree of Utah, quaking aspen occurs across Canada in all provinces and territories, with the possible exception of Nunavut. It occurs at low elevations as far south as northern Nebraska, in the western United States, this tree rarely survives at elevations lower than 1,500 feet due to hot summers experienced below that elevation, and is generally found at 5, 000–12,000 feet. It grows at altitudes as far south as Guanajuato, Mexico. Quaking aspen grows in a variety of climatic conditions. January and July average temperatures range from −30 °C and 16 °C in the Alaska Interior to −3 °C and 23 °C in Fort Wayne, average annual precipitation ranges from 1,020 mm in Gander, Newfoundland and Labrador to as little as 180 mm in the Alaska Interior. The southern limit of the range roughly follows the 24 °C mean July isotherm. Shrub-like dwarf clones exist in environments too cold and dry to be hospitable to full-size trees
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Populus sect. Aigeiros
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Populus section Aigeiros is a section of three species in the genus Populus, the poplars. Like some other species in the genus Populus, they are known as cottonwoods. The species are native to North America, Europe, and western Asia, in the past, as many as six species were recognized, but recent trends have been to accept just three species, treating the others as subspecies of P. deltoides. An important feature of the leaves is the petiole, which is flattened sideways so that the leaves have a type of movement in the wind. Male and female flowers are in catkins, appearing before the leaves in spring. The seeds are borne on cottony structures that allow them to be blown long distances in the air before settling to ground, the cottonwoods are exceptionally tolerant of flooding, erosion, and flood deposits filling around the trunk. Although each of the three species has a different leaf pattern, they all have the same general diamond leaf shape. Eastern cottonwood is one of the largest North American hardwood trees and it is a riparian zone tree. It occurs throughout the eastern United States and in extreme southern Canada, the leaves are alternate and simple, with coarsely toothed edges, and subcordate at the base. The leaf shape is triangular, hence the species name. In the typical subspecies P. d. deltoides, the leaves are broad and triangular, further west, the subspecies P. d. monilifera has somewhat narrower leaves, 5–10 cm wide at the base. This is also the tree of Nebraska, Wyoming. In West Texas, New Mexico, and Colorado, the subspecies P. d. wislizeni occurs, fremonts cottonwood is native to the southwestern United States and western Mexico. In the United States, the species can be found in California, Nevada, arizona, New Mexico, Texas and Colorado. In Mexico, it can be found in the states of Baja California, Baja California Sur, Sonora, Chihuahua, Coahuila, Nuevo León, Mexico State, and Puebla. It differs from the eastern cottonwood mainly in the leaves having fewer, larger serrations on the edge, some taxonomists formerly considered P. fremontii to be a subspecies of P. deltoides. Black poplar is native to Europe and Western Asia, is distinct in its smaller leaves, 5–11 centimetres across. Cottonwoods are widely grown for timber production along wet river banks, the wood is coarse and of fairly low value, used for pallet boxes, shipping crates, and similar purposes where a cheap but strong enough wood is suitable
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Willow
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Most species are known as willow, but some narrow-leaved shrub species are called osier, and some broader-leaved species are referred to as sallow. Some willows are low-growing or creeping shrubs, for example, the dwarf willow rarely exceeds 6 cm in height, though it spreads widely across the ground. Willows all have abundant watery bark sap, which is charged with salicylic acid, soft, usually pliant, tough wood, slender branches. The roots are remarkable for their toughness, size, and tenacity to life, the leaves are typically elongated, but may also be round to oval, frequently with serrated edges. Most species are deciduous, semievergreen willows with coriaceous leaves are rare, e. g. Salix micans, all the buds are lateral, no absolutely terminal bud is ever formed. The buds are covered by a single scale, usually, the bud scale is fused into a cap-like shape, but in some species it wraps around and the edges overlap. The leaves are simple, feather-veined, and typically linear-lanceolate, usually they are serrate, rounded at base, acute or acuminate. The leaf petioles are short, the often very conspicuous, resembling tiny, round leaves. On some species, however, they are small, inconspicuous, in color, the leaves show a great variety of greens, ranging from yellowish to bluish. Willows are dioecious, with male and female flowers appearing as catkins on separate plants and this scale is square, entire, and very hairy. The anthers are rose-colored in the bud, but orange or purple after the flower opens, they are two-celled, the filaments are threadlike, usually pale brown, and often bald. The ovary is one-celled, the style two-lobed, and the ovules numerous, almost all willows take root very readily from cuttings or where broken branches lie on the ground. The few exceptions include the willow and peachleaf willow. One famous example of such growth from cuttings involves the poet Alexander Pope and this twig was planted and thrived, and legend has it that all of Englands weeping willows are descended from this first one. Willows are often planted on the borders of streams so their interlacing roots may protect the bank against the action of the water, frequently, the roots are much larger than the stem which grows from them. Willows are very cross-compatible, and numerous hybrids occur, both naturally and in cultivation, a well-known ornamental example is the weeping willow, which is a hybrid of Peking willow from China and white willow from Europe. The hybrid cultivar Boydii has gained the Royal Horticultural Societys Award of Garden Merit, Willows are used as food plants by the larvae of some Lepidoptera species, such as the mourning cloak butterfly. Ants, such as ants, are common on willows inhabited by aphids, coming to collect aphid honeydew
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Alder
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Alder is the common name of a genus of flowering plants belonging to the birch family Betulaceae. The common name alder evolved from Old English alor, which in turn is derived from Proto-Germanic root aliso, the generic name Alnus is the equivalent Latin name. With a few exceptions, alders are deciduous, and the leaves are alternate, simple and these trees differ from the birches in that the female catkins are woody and do not disintegrate at maturity, opening to release the seeds in a similar manner to many conifer cones. The largest species are red alder on the west coast of North America, by contrast, the widespread Alnus viridis is rarely more than a 5-m-tall shrub. Alders are commonly found near streams, rivers, and wetlands, Alder leaves and sometimes catkins are used as food by numerous butterflies and moths. A. glutinosa and A. viridis are classed as environmental weeds in New Zealand, Alder leaves and especially the roots are important to the ecosystem because they enrich the soil with nitrogen and other nutrients. Alder is particularly noted for its important symbiotic relationship with Frankia alni and this bacterium is found in root nodules, which may be as large as a human fist, with many small lobes, and light brown in colour. The bacterium absorbs nitrogen from the air and makes it available to the tree, Alder, in turn, provides the bacterium with sugars, which it produces through photosynthesis. Because of its abundance, red alder delivers large amounts of nitrogen to enrich forest soils, red alder stands have been found to supply between 120 and 290 pounds of nitrogen per acre annually to the soil. From Alaska to Oregon, Sitka alder characteristically pioneer fresh, gravelly sites at the foot of retreating glaciers, alders are common among the first species to colonize disturbed areas from floods, windstorms, fires, landslides, etc. Alder groves themselves often serve as natural firebreaks since these trees are much less flammable than conifers. Their foliage and leaf litter does not carry a fire well, in addition, the light weight of alder seeds allows for easy dispersal by the wind. Although it outgrows coastal Douglas-fir for the first 25 years, it is shade intolerant. Red alder is the Pacific Northwests largest alder and the most plentiful, alders largely help create conditions favorable for giant conifers that replace them. Alder root nodules Alder roots are parasitized by northern groundcone, the catkins of some alder species have a degree of edibility, and may be rich in protein. Reported to have a bitter and unpleasant taste, they are useful for survival purposes. The wood of certain species is often used to smoke various food items such as coffee, salmon. Most of the pilings that form the foundation of Venice were made from alder trees, Alder bark contains the anti-inflammatory salicin, which is metabolized into salicylic acid in the body
40.
Birch
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A birch is a thin-leaved deciduous hardwood tree of the genus Betula, in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech-oak family Fagaceae, the genus Betula contains 30 to 60 known taxa of which 11 are on the IUCN2011 Green List of Threatened Species. They are a typically rather short-lived pioneer species widespread in the Northern Hemisphere, particularly in northern temperate, Birch species are generally small to medium-sized trees or shrubs, mostly of northern temperate and boreal climates. The simple leaves are alternate, singly or doubly serrate, feather-veined and they often appear in pairs, but these pairs are really borne on spur-like, two-leaved, lateral branchlets. The fruit is a samara, although the wings may be obscure in some species. They differ from the alders in that the female catkins are not woody and disintegrate at maturity, falling apart to release the seeds, unlike the woody, cone-like female alder catkins. The bark of all birches is characteristically marked with long, horizontal lenticels and its decided color gives the common names gray, white, black, silver and yellow birch to different species. The buds form early and are grown by midsummer, all are lateral, no terminal bud is formed. The wood of all the species is close-grained with satiny texture, staminate aments are pendulous, clustered or solitary in the axils of the last leaves of the branch of the year or near the ends of the short lateral branchlets of the year. They form in autumn and remain rigid during the winter. The scales of the staminate aments when mature are broadly ovate, rounded, yellow or orange color below the middle, each scale bears two bractlets and three sterile flowers, each flower consisting of a sessile, membranaceous, usually two-lobed, calyx. Each calyx bears four short filaments with one-celled anthers or strictly, the pistillate aments are erect or pendulous, solitary, terminal on the two-leaved lateral spur-like branchlets of the year. The pistillate scales are oblong-ovate, three-lobed, pale yellow green often tinged with red and these scales bear two or three fertile flowers, each flower consisting of a naked ovary. The ovary is compressed, two-celled, and crowned with two styles, the ovule is solitary. Each scale bear a small, winged nut that is oval. Betula species are organised into five subgenera, pendula and B. pubescens confused, though they are distinct species with different chromosome numbers. This root is derived from *bʰreh₁ǵ- ‘to shine’, in reference to the birchs white bark. The Proto-Germanic rune berkanan is named after the birch, the generic name betula is from Latin, which is a diminutive borrowed from Gaulish betua
41.
Maple
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Acer /ˈeɪsər/ is a genus of trees or shrubs commonly known as maple. There are approximately 128 species, most of which are native to Asia, with a number appearing in Europe, northern Africa. Only one species, Acer laurinum, extends to the Southern Hemisphere, the type species of the genus is the sycamore maple, Acer pseudoplatanus, the most common maple species in Europe. Most maples are trees growing to 10–45 m height, others are shrubs less than 10 meters tall with a number of small trunks originating at ground level. Most species are deciduous, and many are renowned for their autumn colour, but a few in southern Asia. Most are shade-tolerant when young and are often riparian, understory, many of the root systems are typically dense and fibrous, inhibiting the growth of other vegetation underneath them. A few species, notably Acer cappadocicum, frequently produce root sprouts, maples are distinguished by opposite leaf arrangement. The leaves in most species are palmate veined and lobed, with 3 to 9 veins each leading to a lobe, a small number of species differ in having palmate compound, pinnate compound, pinnate veined or unlobed leaves. Several species, including Acer griseum, Acer mandshuricum, Acer maximowiczianum, one species, Acer negundo, has pinnately compound leaves that may be simply trifoliate or may have five, seven, or rarely nine leaflets. A few, such as Acer laevigatum and Acer carpinifolium, have pinnately veined simple leaves, the flowers are regular, pentamerous, and borne in racemes, corymbs, or umbels. They have four or five sepals, four or five petals about 1 –6 mm long, four to ten stamens about 6 –10 mm long, and two pistils or a pistil with two styles. The ovary is superior and has two carpels, whose wings elongate the flowers, making it easy to tell which flowers are female. Maples flower in winter or early spring, in most species with or just after the appearance of the leaves. Maple flowers are green, yellow, orange or red, though individually small, the effect of an entire tree in flower can be striking in several species. Some maples are a spring source of pollen and nectar for bees. The distinctive fruits are called samaras, maple keys, helicopters and these seeds occur in distinctive pairs each containing one seed enclosed in a nutlet attached to a flattened wing of fibrous, papery tissue. They are shaped to spin as they fall and to carry the seeds a considerable distance on the wind, people often call them helicopters due to the way that they spin as they fall. During World War II, the US Army developed an air drop supply carrier that could carry up to 65 pounds of supplies and was based on the Maple seed
42.
Cherry
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A cherry is the fruit of many plants of the genus Prunus, and is a fleshy drupe. The cherry fruits of commerce usually are obtained from a number of species such as cultivars of the sweet cherry. The name cherry also refers to the tree, and is sometimes applied to almonds and visually similar flowering trees in the genus Prunus, as in ornamental cherry, cherry blossom. Wild cherry may refer to any of the species growing outside of cultivation. The subgenus is native to the regions of the Northern Hemisphere. Other cherry fruits are members of subgenus Padus, most eating cherries are derived from either Prunus avium, the sweet cherry, or from Prunus cerasus, the sour cherry. The indigenous range of the sweet cherry extends through most of Europe, western Asia, and parts of northern Africa, and the fruit has been consumed throughout its range since prehistoric times. A cultivated cherry is recorded as having brought to Rome by Lucius Licinius Lucullus from northeastern Anatolia, also known as the Pontus region. Cherries were introduced into England at Teynham, near Sittingbourne in Kent, by order of Henry VIII, cherries arrived in North America early in the settlement of Brooklyn, New York when the region was under Dutch sovereignty. Trades people leased or purchased land to plant orchards and produce gardens, behind the house sold by Anthony Jansen from Salee to Barent Dirksen. Both species originate in Europe and western Asia, they do not cross-pollinate, some other species, although having edible fruit, are not grown extensively for consumption, except in northern regions where the two main species will not grow. Irrigation, spraying, labor, and their propensity to damage from rain, nonetheless, demand is high for the fruit. In commercial production, cherries are harvested by using a mechanized shaker, hand picking is also widely used to harvest the fruit to avoid damage to both fruit and trees. Common rootstocks include Mazzard, Mahaleb, Colt, and Gisela Series, sour cherries require no pollenizer, while few sweet varieties are self-fertile. Like most temperate-latitude trees, cherry seeds require exposure to cold to germinate, the pits are planted in the autumn and seedlings emerge in the spring. A cherry tree will take three to four years in the field to produce its first crop of fruit, and seven years to attain full maturity, because of the cold-weather requirement, none of the Prunus genus can grow in tropical climates. Cherries have a growing season and can grow in most temperate latitudes. Cherries blossom in April and the season for the cherry harvest is in the summer
43.
Cyperaceae
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The Cyperaceae are a family of monocotyledonous graminoid flowering plants known as sedges, which superficially resemble grasses and rushes. The family is large, with some 5,500 known species described in about 90 genera and these species are widely distributed, with the centers of diversity for the group occurring in tropical Asia and tropical South America. While sedges may be growing in almost all environments, many are associated with wetlands. Ecological communities dominated by sedges are known as sedgelands, features distinguishing members of the sedge family from grasses or rushes are stems with triangular cross-sections and leaves that are spirally arranged in three ranks. Some well-known sedges include the chestnut and the papyrus sedge. This family also includes cotton-grass, spike-rush, sawgrass, nutsedge or nutgrass, and white star sedge
44.
Nymphaeaceae
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Nymphaeaceae /ˌnɪmfiːˈeɪsiː/ is a family of flowering plants, commonly called water lilies. They live as rhizomatous aquatic herbs in temperate and tropical climates around the world, the family contains five genera with about 70 known species. Water lilies are rooted in soil in bodies of water, with leaves, the leaves are round, with a radial notch in Nymphaea and Nuphar, but fully circular in Victoria and Euryale. Genera with more parts, Nuphar, Nymphaea, Victoria, have a beetle pollination syndrome, while genera with fewer parts are pollinated by flies or bees. Thus, the number of relatively unspecialized floral organs in the Nymphaeaceae is not an ancestral condition for the clade. Water lilies do not have leaves in the winter time. The leftover of internal pressure is embodied by the constant streams of bubbles that outbreak when rising leaves are ruptured in the spring. Methane is still penetrating the roots and rhizome in the summer, moving fast up the petioles, the Nymphaeaceae are aquatic, rhizomatous herbs. The family is characterized by scattered vascular bundles in the stems. Hairs are simple, usually producing mucilage, stipules are either present or absent. Flowers are solitary, bisexual, radial, with a pedicel and usually floating or raised above the surface of the water. Sepals are 4-12, distinct to connate, imbricate, and often petal-like, petals lacks or 8 to numerous, inconspicuous to showy, often intergrading with stamens. Stamens are 3 to numerous, the innermost sometimes represented by staminodes, carpels are 3 to numerous, distinct or connate. Fruit is an aggregate of nuts, a berry, or an irregularly dehiscent fleshy capsule, seeds are often arillate, more or less lacking sperm. Nymphaeaceae has been investigated systematically for decades because botanists considered their floral morphology to represent one of the earliest groups of angiosperms, modern genetic analyses by the Angiosperm Phylogeny Group researchers has confirmed its basal position among flowering plants. In addition, the Nymphaeaceae are more diverse and geographically dispersed than other basal angiosperms. Nymphaeaceae is placed in the order Nymphaeales, which is the second diverging group of angiosperms after Amborella in the most widely accepted flowering plant classification system, Nymphaeaceae is a small family of three to six genera, Barclaya, Euryale, Nuphar, Nymphaea, Ondinea, and Victoria. The genus Barclaya is sometimes given rank as its own family, Barclayaceae, on the basis of a perianth tube arising from the top of the ovary
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One or more of the preceding sentences incorporates text from a publication now in the public domain: Lydekker, Richard (1911). "Beaver". In Chisholm, Hugh. Encyclopædia Britannica. 3 (11th ed.). Cambridge University Press. p. 600.
. PMID 2178552. Retrieved 2011-03-05.
One or more of the preceding sentences incorporates text from a publication now in the 
