The Eocene ( IPA : / ˈ iː ə s iː n , ˈ iː oʊ -/ EE -ə-seen, EE -oh- ) is a geological epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period in the modern Cenozoic Era . The name Eocene comes from the Ancient Greek Ἠώς ( Ēṓs , " Dawn ") and καινός ( kainós , "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch.
156-542: The pecan ( / p ɪ ˈ k æ n / pih- KAN , also US : / p ɪ ˈ k ɑː n , ˈ p iː k æ n / pih- KAHN , PEE -kan , UK : / ˈ p iː k ən / PEE -kən ; Carya illinoinensis ) is a species of hickory native to the Southern United States and northern Mexico in the region of the Mississippi River . The tree is cultivated for its seed primarily in
312-707: A cot–caught merger , which is rapidly spreading throughout the whole country. However, the South, Inland North, and a Northeastern coastal corridor passing through Rhode Island, New York City, Philadelphia, and Baltimore typically preserve an older cot–caught distinction. For that Northeastern corridor, the realization of the THOUGHT vowel is particularly marked , as depicted in humorous spellings, like in tawk and cawfee ( talk and coffee ), which intend to represent it being tense and diphthongal : [oə] . A split of TRAP into two separate phonemes , using different
468-520: A pronunciations for example in gap [æ] versus gas [eə] , further defines New York City as well as Philadelphia–Baltimore accents. Most Americans preserve all historical /r/ sounds, using what is known as a rhotic accent . The only traditional r -dropping (or non-rhoticity) in regional U.S. accents variably appears today in eastern New England , New York City , and some of the former plantation South primarily among older speakers (and, relatedly, some African-American Vernacular English across
624-631: A complex phenomenon of "both convergence and divergence": some accents are homogenizing and leveling , while others are diversifying and deviating further away from one another. Having been settled longer than the American West Coast, the East Coast has had more time to develop unique accents, and it currently comprises three or four linguistically significant regions, each of which possesses English varieties both different from each other as well as quite internally diverse: New England ,
780-1135: A complex practice, based on the Alternate Bearing Index (ABI) and their period of pollinating. Commercial growers are most concerned with the ABI, which describes a cultivar's likelihood to bear on alternating years (index of 1.0 signifies the highest likelihood of bearing little to nothing every other year). The period of pollination groups all cultivars into two families: those that shed pollen before they can receive pollen ( protandrous ) and those that shed pollen after becoming receptive to pollen ( protogynous ). State-level resources provide recommended varieties for specific regions. Native pecans in Mexico are adapted from zones 9 to 11. Little or no breeding work has been done with these populations. A few selections from native stands have been made, such as Frutosa and Norteña, which are recommended for cultivation in Mexico. Improved varieties recommended for cultivation in Mexico are USDA-developed cultivars. This represents
936-447: A consonant, such as in pearl , car and fort . Non-rhotic American accents, those that do not pronounce ⟨r⟩ except before a vowel, such as some accents of Eastern New England , New York City , and African-Americans , and a specific few (often older ones) spoken by Southerners , are often quickly noticed by General American listeners and perceived as sounding especially ethnic, regional, or antiquated. Rhoticity
1092-543: A crop in low-chill zones. Active breeding and selection is carried out by the USDA Agricultural Research Service with growing locations at Brownwood and College Station, Texas . University of Georgia has a breeding program at the Tifton campus working on selecting pecan varieties adapted to subtropical Southeastern U.S. growing conditions. While selection work has been done since
1248-555: A delicacy, the commercial growth of pecans in the United States did not begin until the 1880s. As of 2014, the United States produced an annual crop of 119.8 million kilograms (264.2 million pounds), with 75% of the total crop produced in Georgia , New Mexico , and Texas . They can be grown from USDA hardiness zones approximately 5 to 9, and grow best where summers are long, hot and humid. The nut harvest for growers
1404-541: A gap in breeding development given that native pecans can be cultivated at least down to the Yucatán peninsula while the USDA cultivars have chilling hour requirements greater than those occurring in much of the region. Some regions of the U.S. such as parts of Florida and Puerto Rico are zone 10 or higher, and these regions have limited options for pecan cultivation. 'Western' is the only commonly available variety that can make
1560-431: A large body of water is also present. In an attempt to try to mitigate the cooling polar temperatures, large lakes were proposed to mitigate seasonal climate changes. To replicate this case, a lake was inserted into North America and a climate model was run using varying carbon dioxide levels. The model runs concluded that while the lake did reduce the seasonality of the region greater than just an increase in carbon dioxide,
1716-699: A large enough scale to significantly affect production. Varieties that are available and adapted (e.g., 'Major', 'Martzahn', 'Witte', 'Greenriver', 'Mullahy', and 'Posey') in zones 6 and farther north are almost entirely selections from wild stands. 'Kanza', a northern-adapted release from the USDA breeding program, is a grafted pecan having high productivity and quality, and cold tolerance. Pecans are subject to various diseases, pests, and physiological disorders that can limit tree growth and fruit production. These range from scab to hickory shuckworm to shuck decline. Pecans are prone to infection by bacteria and fungi such as pecan scab , especially in humid conditions. Scab
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#17327805404571872-591: A merger with the THOUGHT ( caught ) set. Having taken place prior to the unrounding of the cot vowel, it results in lengthening and perhaps raising, merging the more recently separated vowel into the THOUGHT vowel in the following environments: before many instances of /f/ , /θ/ , and particularly /s/ (as in Austria, cloth, cost, loss, off, often, etc.), a few instances before /ŋ/ (as in strong, long, wrong ), and variably by region or speaker in gone , on , and certain other words. Unlike American accents,
2028-636: A nice day , for sure); many are now distinctly old-fashioned (swell, groovy). Some English words now in general use, such as hijacking, disc jockey , boost, bulldoze and jazz , originated as American slang. American English has always shown a marked tendency to use words in different parts of speech and nouns are often used as verbs . Examples of nouns that are now also verbs are interview, advocate, vacuum, lobby, pressure, rear-end, transition, feature, profile, hashtag, head, divorce, loan, estimate, X-ray, spearhead, skyrocket, showcase, bad-mouth, vacation , major, and many others. Compounds coined in
2184-400: A pecan genome showed that DNA introgressed from C. aquatica (water hickory), C. myristiciformis (nutmeg hickory), and C. cordiformis (bitternut hickory) is present in commercial pecan varieties grown today. In 1919, the 36th Texas Legislature made the pecan tree the state tree of Texas ; in 2001, the pecan was declared the state's official "health nut", and in 2013, pecan pie was made
2340-480: A process of extensive dialect mixture and leveling in which English varieties across the colonies became more homogeneous compared with the varieties in Britain. English thus predominated in the colonies even by the end of the 17th century's first immigration of non-English speakers from Western Europe and Africa. Additionally, firsthand descriptions of a fairly uniform American English (particularly in contrast to
2496-511: A role in triggering the ETM2 and ETM3. An enhancement of the biological pump proved effective at sequestering excess carbon during the recovery phases of these hyperthermals. These hyperthermals led to increased perturbations in planktonic and benthic foraminifera , with a higher rate of fluvial sedimentation as a consequence of the warmer temperatures. Unlike the PETM, the lesser hyperthermals of
2652-680: A series of other vowel shifts in the same region, known by linguists as the " Inland North ". The Inland North shares with the Eastern New England dialect (including Boston accents ) a backer tongue positioning of the GOOSE /u/ vowel (to [u] ) and the MOUTH /aʊ/ vowel (to [ɑʊ~äʊ] ) in comparison to the rest of the country. Ranging from northern New England across the Great Lakes to Minnesota, another Northern regional marker
2808-533: A significant amount of water vapor is released. Another requirement for polar stratospheric clouds is cold temperatures to ensure condensation and cloud production. Polar stratospheric cloud production, since it requires the cold temperatures, is usually limited to nighttime and winter conditions. With this combination of wetter and colder conditions in the lower stratosphere, polar stratospheric clouds could have formed over wide areas in Polar Regions. To test
2964-462: A survey, completed in 2003, polling English speakers across the United States about their specific everyday word choices, hoping to identify regionalisms. The study found that most Americans prefer the term sub for a long sandwich, soda (but pop in the Great Lakes region and generic coke in the South) for a sweet and bubbly soft drink , you or you guys for the plural of you (but y'all in
3120-509: A traditional Southern U.S. dish . Butter pecan is also a common flavor in cookies, cakes, and ice creams. Pecans are a significant ingredient in American praline candy. Other applications of cooking with pecans include pecan oil and pecan butter. Pecan wood is used in making furniture and wood flooring, as well as flavoring fuel for smoking meats , giving grilled foods a sweet and nutty flavor stronger than many fruit woods. A pecan nut
3276-453: A variation of American English in these islands. In 2021, about 245 million Americans, aged 5 or above, spoke English at home: a majority of the United States total population of roughly 330 million people. The United States has never had an official language at the federal level, but English is commonly used at the federal level and in states without an official language. 32 of the 50 states, in some cases as part of what has been called
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#17327805404573432-775: A wide variety of climate conditions that includes the warmest climate in the Cenozoic Era , and arguably the warmest time interval since the Permian-Triassic mass extinction and Early Triassic, and ends in an icehouse climate. The evolution of the Eocene climate began with warming after the end of the Paleocene–Eocene Thermal Maximum (PETM) at 56 Ma to a maximum during the Eocene Optimum at around 49 Ma. During this period of time, little to no ice
3588-554: Is 3–4 mm ( 1 ⁄ 8 – 5 ⁄ 32 in) thick, starts out green, and turns brown at maturity, at which time it splits off in four sections to release the thin-shelled seed. Carya illinoinensis , is a member of the Juglandaceae family. Juglandaceae are represented worldwide by seven and ten extant genera and more than 60 species. Most of these species are concentrated in the Northern Hemisphere of
3744-562: Is 4% water, 72% fat, 9% protein , and 14% carbohydrates . In a 100 g reference amount, pecans provide 690 calories and are a rich source (20% or more of the Daily Value , DV) of dietary fiber (38% DV), manganese (214% DV), magnesium (34% DV), phosphorus (40% DV), zinc (48% DV), and thiamine (57% DV). Pecans are a moderate source (10–19% DV) of iron and B vitamins . Pecan fat content consists principally of monounsaturated fatty acids, mainly oleic acid (57% of total fat), and
3900-501: Is a dynamic epoch that represents global climatic transitions between two climatic extremes, transitioning from the hot house to the cold house. The beginning of the Eocene is marked by the Paleocene–Eocene Thermal Maximum , a short period of intense warming and ocean acidification brought about by the release of carbon en masse into the atmosphere and ocean systems, which led to a mass extinction of 30–50% of benthic foraminifera (single-celled species which are used as bioindicators of
4056-654: Is also associated with the United States, perhaps mostly in the Midwest and the South. American accents that have not undergone the cot–caught merger (the lexical sets LOT and THOUGHT ) have instead retained a LOT – CLOTH split : a 17th-century distinction in which certain words (labeled as the CLOTH lexical set ) separated away from the LOT set. The split, which has now reversed in most British English, simultaneously shifts this relatively recent CLOTH set into
4212-664: Is also home to a creole language known commonly as Hawaiian Pidgin , and some Hawaii residents speak English with a Pidgin-influenced accent. American English also gave rise to some dialects outside the country, for example, Philippine English , beginning during the American occupation of the Philippines and subsequently the Insular Government of the Philippine Islands ; Thomasites first established
4368-459: Is an important factor in the creation of the primary Type II polar stratospheric clouds that were created in the early Eocene. Since water vapor is the only supporting substance used in Type II polar stratospheric clouds, the presence of water vapor in the lower stratosphere is necessary where in most situations the presence of water vapor in the lower stratosphere is rare. When methane is oxidized,
4524-538: Is common in most American accents despite being now rare in England because, during the 17th-century British colonization, nearly all dialects of English were rhotic, and most North American English simply remained that way. The preservation of rhoticity in North America was also supported by continuing waves of rhotic-accented Scotch-Irish immigrants, most intensely during the 18th century (and moderately during
4680-638: Is considered to be primarily due to carbon dioxide increases, because carbon isotope signatures rule out major methane release during this short-term warming. A sharp increase in atmospheric carbon dioxide was observed with a maximum of 4,000 ppm: the highest amount of atmospheric carbon dioxide detected during the Eocene. Other studies suggest a more modest rise in carbon dioxide levels. The increase in atmospheric carbon dioxide has also been hypothesised to have been driven by increased seafloor spreading rates and metamorphic decarbonation reactions between Australia and Antarctica and increased amounts of volcanism in
4836-594: Is conventionally divided into early (56–47.8 Ma), middle (47.8–38 Ma), and late (38–33.9 Ma) subdivisions. The corresponding rocks are referred to as lower, middle, and upper Eocene. The Ypresian Stage constitutes the lower, the Priabonian Stage the upper; and the Lutetian and Bartonian stages are united as the middle Eocene. The Western North American floras of the Eocene were divided into four floral "stages" by Jack Wolfe ( 1968 ) based on work with
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4992-494: Is known in linguistics as General American ; it covers a fairly uniform accent continuum native to certain regions of the U.S. but especially associated with broadcast mass media and highly educated speech. However, historical and present linguistic evidence does not support the notion of there being one single mainstream American accent . The sound of American English continues to evolve, with some local accents disappearing, but several larger regional accents having emerged in
5148-537: Is little agreement in the United States regarding the "correct" pronunciation, even regionally. In 1927, the National Pecan Growers Association acknowledged variant pronunciations while designating one as official and correct: "pronounced as though spelled pea-con ... those in the habit of using any other pronunciation therefore be requested henceforth to adopt exclusively the pronunciation above specified above and hereby adopted by
5304-455: Is now Louisiana , Texas , and Mexico. These Spanish explorers called the pecan, nuez de la arruga , which roughly translates to "wrinkle nut". Because of their familiarity with the genus Juglans , these early explorers referred to the nuts as nogales and nueces , the Spanish terms for "walnut trees" and "fruit of the walnut". They noted the particularly thin shell and acorn-like shape of
5460-420: Is often identified by Americans as a "country" accent, and is defined by the /aɪ/ vowel losing its gliding quality : [aː] , the initiation event for a complicated Southern vowel shift, including a " Southern drawl " that makes short front vowels into distinct-sounding gliding vowels . The fronting of the vowels of GOOSE , GOAT , MOUTH , and STRUT tends to also define Southern accents as well as
5616-720: Is short lived, as benthic oxygen isotope records indicate a return to cooling at ~40 Ma. At the end of the MECO, the MLEC resumed. Cooling and the carbon dioxide drawdown continued through the late Eocene and into the Eocene–Oligocene transition around 34 Ma. The post-MECO cooling brought with it a major aridification trend in Asia, enhanced by retreating seas. A monsoonal climate remained predominant in East Asia. The cooling during
5772-547: Is the common language at home, in public, and in government. Eocene 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 brief period in which the concentration of the carbon isotope C in the atmosphere was exceptionally low in comparison with the more common isotope C . The average temperature of Earth at
5928-408: Is the most destructive disease affecting pecan trees untreated with fungicides. Recommendations for preventive spray materials and schedules are available from state-level resources. Various insects feed on the leaves, stems, and developing nuts. These include ambrosia beetles , twig girdlers, pecan nut casebearer , hickory shuckworm, phylloxera , curculio , weevils, and several aphid species. In
6084-535: Is the period of time when the Antarctic ice sheet began to rapidly expand. Greenhouse gases, in particular carbon dioxide and methane , played a significant role during the Eocene in controlling the surface temperature. The end of the PETM was met with very large sequestration of carbon dioxide into the forms of methane clathrate , coal , and crude oil at the bottom of the Arctic Ocean , that reduced
6240-469: Is the variable fronting of /ɑ/ before /r/ , for example, appearing four times in the stereotypical Boston shibboleth Park the car in Harvard Yard . Several other phenomena serve to distinguish regional U.S. accents. Boston , Pittsburgh , Upper Midwestern , and Western U.S. accents have fully completed a merger of the LOT vowel with the THOUGHT vowel ( /ɑ/ and /ɔ/ , respectively):
6396-507: Is typically around mid-October. Outside the U.S., Mexico produces nearly half of the world's total, similar in volume to that of the U.S., together accounting for 93% of global production. Pecan trees require large quantities of water during the growing season, and most orchards in the region use flood irrigation to optimize consumptive water use and production of mature pecans. Generally, two or more trees of different cultivars must be present to pollinate each other. Choosing cultivars can be
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6552-740: The Cenozoic in 1840 in place of the Tertiary, and Austrian paleontologist Moritz Hörnes introduced the Paleogene for the Eocene and Neogene for the Miocene and Pliocene in 1853. After decades of inconsistent usage, the newly formed International Commission on Stratigraphy (ICS), in 1969, standardized stratigraphy based on the prevailing opinions in Europe: the Cenozoic Era subdivided into
6708-482: The English-only movement , have adopted legislation granting official or co-official status to English. Typically only "English" is specified, not a particular variety like American English. (From 1923 to 1969, the state of Illinois recognized its official language as "American", meaning American English.) Puerto Rico is the largest example of a United States territory in which another language – Spanish –
6864-502: The Eocene . The fruits of the pecan genus Carya differ from those of the walnut genus Juglans only in the formation of the husk of the fruit. The husks of walnuts develop from the bracts, bracteoles and sepals, or sepals only. The husks of pecans develop from the bracts and the bracteoles only. Pecans are one of the most recently domesticated of the major crops . Although wild pecans were well known among native and colonial Americans as
7020-622: The Mid-Atlantic states (including a New York accent as well as a unique Philadelphia–Baltimore accent ), and the South . As of the 20th century, the middle and eastern Great Lakes area , Chicago being the largest city with these speakers, also ushered in certain unique features, including the fronting of the LOT /ɑ/ vowel in the mouth toward [a] and tensing of the TRAP /æ/ vowel wholesale to [eə] . These sound changes have triggered
7176-642: The Middle Eocene Climatic Optimum (MECO). At around 41.5 Ma, stable isotopic analysis of samples from Southern Ocean drilling sites indicated a warming event for 600,000 years. A similar shift in carbon isotopes is known from the Northern Hemisphere in the Scaglia Limestones of Italy. Oxygen isotope analysis showed a large negative change in the proportion of heavier oxygen isotopes to lighter oxygen isotopes, which indicates an increase in global temperatures. The warming
7332-551: The Native American languages . Examples of such names are opossum , raccoon , squash , moose (from Algonquian ), wigwam , and moccasin . American English speakers have integrated traditionally non-English terms and expressions into the mainstream cultural lexicon; for instance, en masse , from French ; cookie , from Dutch ; kindergarten from German , and rodeo from Spanish . Landscape features are often loanwords from French or Spanish, and
7488-761: The Puget Group fossils of King County, Washington . The four stages, Franklinian , Fultonian , Ravenian , and Kummerian covered the Early Eocene through early Oligocene, and three of the four were given informal early/late substages. Wolfe tentatively deemed the Franklinian as Early Eocene, the Fultonian as Middle Eocene, the Ravenian as Late, and the Kummerian as Early Oligocene. The beginning of
7644-458: The amount of oxygen in the Earth's atmosphere more or less doubled. During the warming in the early Eocene between 55 and 52 Ma, there were a series of short-term changes of carbon isotope composition in the ocean. These isotope changes occurred due to the release of carbon from the ocean into the atmosphere that led to a temperature increase of 4–8 °C (7.2–14.4 °F) at the surface of
7800-722: The francophile tastes of the 19th century Victorian era Britain (for example they preferred programme for program , manoeuvre for maneuver , cheque for check , etc.). AmE almost always uses -ize in words like realize . BrE prefers -ise , but also uses -ize on occasion (see: Oxford spelling ). There are a few differences in punctuation rules. British English is more tolerant of run-on sentences , called " comma splices " in American English, and American English prefers that periods and commas be placed inside closing quotation marks even in cases in which British rules would place them outside. American English also favors
7956-415: The polyunsaturated fatty acid, linoleic acid (30% of total fat). Before European settlement, pecans were widely consumed and traded by Native Americans. As a wild forage, the fruit of the previous growing season is commonly still edible when found on the ground. Pecans first became known to Europeans in the 16th century. The first Europeans to come into contact with pecans were Spanish explorers in what
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#17327805404578112-417: The proxy data . Using all different ranges of greenhouse gasses that occurred during the early Eocene, models were unable to produce the warming that was found at the poles and the reduced seasonality that occurs with winters at the poles being substantially warmer. The models, while accurately predicting the tropics, tend to produce significantly cooler temperatures of up to 20 °C (36 °F) colder than
8268-603: The southeast United States . After the Paleocene–Eocene Thermal Maximum, members of the Equoidea arose in North America and Europe, giving rise to some of the earliest equids such as Sifrhippus and basal European equoids such as the palaeothere Hyracotherium . Some of the later equoids were especially species-rich; Palaeotherium , ranging from small to very large in size, is known from as many as 16 species. Established large-sized mammals of
8424-764: The 18th century; apartment , shanty in the 19th century; project, condominium , townhouse , mobile home in the 20th century; and parts thereof ( driveway , breezeway, backyard ) . Industry and material innovations from the 19th century onwards provide distinctive new words, phrases, and idioms through railroading (see further at rail terminology ) and transportation terminology, ranging from types of roads ( dirt roads , freeways ) to infrastructure ( parking lot , overpass , rest area ), to automotive terminology often now standard in English internationally. Already existing English words—such as store , shop , lumber —underwent shifts in meaning; others remained in
8580-546: The 20th century. The use of English in the United States is a result of British colonization of the Americas . The first wave of English-speaking settlers arrived in North America during the early 17th century, followed by further migrations in the 18th and 19th centuries. During the 17th and 18th centuries, dialects from many different regions of England and the British Isles existed in every American colony, allowing
8736-441: The 50 U.S. states . Since the late 20th century, American English has become the most influential form of English worldwide. Varieties of American English include many patterns of pronunciation, vocabulary, grammar and particularly spelling that are unified nationwide but distinct from other English dialects around the world. Any American or Canadian accent perceived as lacking noticeably local, ethnic, or cultural markers
8892-659: The Association." The pecan tree is a large deciduous tree, growing to 20–40 m (66–131 ft) in height, rarely to 44 m (144 ft). It typically has a spread of 12–23 m (39–75 ft) with a trunk up to 2 m (6 ft 7 in) diameter. A 10-year-old sapling grown in optimal conditions will stand about 5 m (16 ft) tall. The leaves are alternate, 30–45 cm (12–18 in) long, and pinnate with 9–17 leaflets, each leaflet 5–12 cm (2– 4 + 1 ⁄ 2 in) long and 2–6 cm (1– 2 + 1 ⁄ 2 in) broad. A pecan, like
9048-671: The Azolla Event. This cooling trend at the end of the EECO has also been proposed to have been caused by increased siliceous plankton productivity and marine carbon burial, which also helped draw carbon dioxide out of the atmosphere. Cooling after this event, part of a trend known as the Middle-Late Eocene Cooling (MLEC), continued due to continual decrease in atmospheric carbon dioxide from organic productivity and weathering from mountain building . Many regions of
9204-627: The British form is a back-formation , such as AmE burglarize and BrE burgle (from burglar ). However, while individuals usually use one or the other, both forms will be widely understood and mostly used alongside each other within the two systems. While written American English is largely standardized across the country and spoken American English dialects are highly mutually intelligible, there are still several recognizable regional and ethnic accents and lexical distinctions. The regional sounds of present-day American English are reportedly engaged in
9360-404: The EECO. Relative to present-day values, bottom water temperatures are 10 °C (18 °F) higher according to isotope proxies. With these bottom water temperatures, temperatures in areas where deep water forms near the poles are unable to be much cooler than the bottom water temperatures. An issue arises, however, when trying to model the Eocene and reproduce the results that are found with
9516-548: The Early Eocene had negligible consequences for terrestrial mammals. These Early Eocene hyperthermals produced a sustained period of extremely hot climate known as the Early Eocene Climatic Optimum (EECO). During the early and middle EECO, the superabundance of the euryhaline dinocyst Homotryblium in New Zealand indicates elevated ocean salinity in the region. One of the unique features of
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#17327805404579672-440: The Earth including the poles. Tropical forests extended across much of modern Africa, South America, Central America, India, South-east Asia and China. Paratropical forests grew over North America, Europe and Russia, with broad-leafed evergreen and broad-leafed deciduous forests at higher latitudes. Polar forests were quite extensive. Fossils and even preserved remains of trees such as swamp cypress and dawn redwood from
9828-413: The East Coast (perhaps in imitation of 19th-century London speech), even the East Coast has gradually begun to restore rhoticity, due to it becoming nationally prestigious in the 20th century. The pronunciation of ⟨r⟩ is a postalveolar approximant [ ɹ̠ ] or retroflex approximant [ ɻ ] , but a unique "bunched tongue" variant of the approximant r sound
9984-566: The Eocene have been found on Ellesmere Island in the Arctic . Even at that time, Ellesmere Island was only a few degrees in latitude further south than it is today. Fossils of subtropical and even tropical trees and plants from the Eocene also have been found in Greenland and Alaska . Tropical rainforests grew as far north as northern North America and Europe . Palm trees were growing as far north as Alaska and northern Europe during
10140-619: The Eocene include the Uintatherium , Arsinoitherium , and brontotheres , in which the former two, unlike the latter, did not belong to ungulates but groups that became extinct shortly after their establishments. Large terrestrial mammalian predators had already existed since the Paleocene, but new forms now arose like Hyaenodon and Daphoenus (the earliest lineage of a once-successful predatory family known as bear dogs ). Entelodonts meanwhile established themselves as some of
10296-544: The Eocene's climate as mentioned before was the equable and homogeneous climate that existed in the early parts of the Eocene. A multitude of proxies support the presence of a warmer equable climate being present during this period of time. A few of these proxies include the presence of fossils native to warm climates, such as crocodiles , located in the higher latitudes, the presence in the high latitudes of frost-intolerant flora such as palm trees which cannot survive during sustained freezes, and fossils of snakes found in
10452-664: The Eocene, and compression was replaced with crustal extension that ultimately gave rise to the Basin and Range Province . The Kishenehn Basin, around 1.5 km in elevation during the Lutetian, was uplifted to an altitude of 2.5 km by the Priabonian. Huge lakes formed in the high flat basins among uplifts, resulting in the deposition of the Green River Formation lagerstätte . At about 35 Ma, an asteroid impact on
10608-399: The Eocene-Oligocene transition is the timing of the creation of the circulation is uncertain. For Drake Passage , sediments indicate the opening occurred ~41 Ma while tectonics indicate that this occurred ~32 Ma. Solar activity did not change significantly during the greenhouse-icehouse transition across the Eocene-Oligocene boundary. During the early-middle Eocene, forests covered most of
10764-510: The Inland North. Rather than one particular accent, General American is best defined as an umbrella covering an American accent that does not incorporate features associated with some particular region, ethnicity, or socioeconomic group. Typical General American features include rhoticity , the father–bother merger , Mary–marry–merry merger , pre-nasal "short a " tensing , and other particular vowel sounds . General American features are embraced most by Americans who are highly educated or in
10920-439: The Kummerian was refined by Gregory Retallack et al (2004) as 40 Mya, with a refined end at the Eocene-Oligocene boundary where the younger Angoonian floral stage starts. During the Eocene, the continents continued to drift toward their present positions. At the beginning of the period, Australia and Antarctica remained connected, and warm equatorial currents may have mixed with colder Antarctic waters, distributing
11076-426: The MECO was responsible for a globally uniform 4° to 6°C warming of both the surface and deep oceans, as inferred from foraminiferal stable oxygen isotope records. The resumption of a long-term gradual cooling trend resulted in a glacial maximum at the late Eocene/early Oligocene boundary. The end of the Eocene was also marked by the Eocene–Oligocene extinction event , also known as the Grande Coupure . The Eocene
11232-679: The MECO. Both groups of modern ungulates (hoofed animals) became prevalent because of a major radiation between Europe and North America, along with carnivorous ungulates like Mesonyx . Early forms of many other modern mammalian orders appeared, including horses (most notably the Eohippus ), bats , proboscidians (elephants), primates, and rodents . Older primitive forms of mammals declined in variety and importance. Important Eocene land fauna fossil remains have been found in western North America, Europe, Patagonia , Egypt , and southeast Asia . Marine fauna are best known from South Asia and
11388-599: The New World, but some can be found on every continent except Antarctica . The first fossil examples of Juglandaceae appear during the Cretaceous . Differentiation between the subfamilies of Engelhardioideae and Juglandioideae occurred during the early Paleogene , about 64 million years ago. Extant examples of Engelhardioideae are generally tropical and evergreen, while those of Juglandioideae are deciduous and found in more temperate zones. The second major step in
11544-469: The North American continent, and it reduced the seasonal variation of temperature by up to 75%. While orbital parameters did not produce the warming at the poles, the parameters did show a great effect on seasonality and needed to be considered. Another method considered for producing the warm polar temperatures were polar stratospheric clouds . Polar stratospheric clouds are clouds that occur in
11700-415: The PETM event in the sea floor or wetland environments. For contrast, today the carbon dioxide levels are at 400 ppm or 0.04%. During the early Eocene, methane was another greenhouse gas that had a drastic effect on the climate. Methane has 30 times more of a warming effect than carbon dioxide on a 100-year scale (i.e., methane has a global warming potential of 29.8±11). Most of the methane released to
11856-596: The Pecan as its official state nut in 2023. In 1988, Oklahoma enacted an official state meal which included pecan pie. American English American English , sometimes called United States English or U.S. English , is the set of varieties of the English language native to the United States. English is the most widely spoken language in the United States ; the de facto common language used in government, education, and commerce; and an official language in 32 of
12012-573: The South), sneakers for athletic shoes (but often tennis shoes outside the Northeast), and shopping cart for a cart used for carrying supermarket goods. American English and British English (BrE) often differ at the levels of phonology, phonetics, vocabulary, and, to a much lesser extent, grammar and orthography. The first large American dictionary, An American Dictionary of the English Language , known as Webster's Dictionary ,
12168-575: The Southeastern U.S. due to increased disease pressure. Selection programs are ongoing at the state level, with Alabama, Arkansas, Florida, Georgia, Kansas, Missouri, New Mexico, and others having trial plantings. Varieties adapted from the southern tier of states north through some parts of Iowa and even into southern Canada are available from nurseries. Production potential drops significantly when planted further north than Tennessee. Most breeding efforts for northern-adapted varieties have not been on
12324-453: The Southeastern U.S., nickel deficiency in C. illinoinensis produces a disorder called "mouse-ear" in trees fertilized with urea . Similarly, zinc deficiency causes rosetting of the leaves. Various other disorders are documented, including canker disease and shuck decline complex. Pecan seeds are edible, with a rich, buttery flavor. They can be eaten fresh or roasted, or used in cooking, particularly in sweet desserts, such as pecan pie ,
12480-531: The Tertiary and Quaternary sub-eras, and the Tertiary subdivided into the Paleogene and Neogene periods. In 1978, the Paleogene was officially defined as the Paleocene, Eocene, and Oligocene epochs; and the Neogene as the Miocene and Pliocene epochs. In 1989, Tertiary and Quaternary were removed from the time scale due to the arbitrary nature of their boundary, but Quaternary was reinstated in 2009. The Eocene
12636-528: The U.S. Several verbs ending in -ize are of U.S. origin; for example, fetishize, prioritize, burglarize, accessorize, weatherize , etc.; and so are some back-formations (locate, fine-tune, curate, donate, emote, upholster and enthuse). Among syntactic constructions that arose are outside of, headed for, meet up with, back of, etc. Americanisms formed by alteration of some existing words include notably pesky, phony, rambunctious, buddy, sundae , skeeter, sashay and kitty-corner. Adjectives that arose in
12792-570: The U.S. are for instance foothill , landslide (in all senses), backdrop , teenager , brainstorm , bandwagon , hitchhike , smalltime, and a huge number of others. Other compound words have been founded based on industrialization and the wave of the automobile: five-passenger car, four-door sedan, two-door sedan, and station-wagon (called an estate car in British English). Some are euphemistic ( human resources , affirmative action , correctional facility ). Many compound nouns have
12948-676: The U.S. are, for example, lengthy, bossy, cute and cutesy, punk (in all senses), sticky (of the weather), through (as in "finished"), and many colloquial forms such as peppy or wacky . A number of words and meanings that originated in Middle English or Early Modern English and that have been in everyday use in the United States have since disappeared in most varieties of British English; some of these have cognates in Lowland Scots . Terms such as fall ("autumn"), faucet ("tap"), diaper ("nappy"; itself unused in
13104-529: The U.S. states of Georgia , New Mexico , and Texas , and in Mexico . The seed is an edible nut used as a snack and in various recipes, such as praline candy and pecan pie . The pecan is the state nut of Alabama , Arkansas , California , Texas, and Louisiana , and is also the state tree of Texas. Pecan derives from an Algonquian word variously referring to pecans, walnuts, and hickory nuts. There are many pronunciations, some regional and others not. There
13260-530: The U.S. while changing in Britain. Science, urbanization, and democracy have been important factors in bringing about changes in the written and spoken language of the United States. From the world of business and finance came new terms ( merger , downsize , bottom line ), from sports and gambling terminology came, specific jargon aside, common everyday American idioms, including many idioms related to baseball . The names of some American inventions remained largely confined to North America ( elevator [except in
13416-427: The U.S.), candy ("sweets"), skillet , eyeglasses , and obligate are often regarded as Americanisms. Fall for example came to denote the season in 16th century England, a contraction of Middle English expressions like "fall of the leaf" and "fall of the year." Gotten ( past participle of get ) is often considered to be largely an Americanism. Other words and meanings were brought back to Britain from
13572-541: The U.S., especially in the second half of the 20th century; these include hire ("to employ"), I guess (famously criticized by H. W. Fowler ), baggage , hit (a place), and the adverbs overly and presently ("currently"). Some of these, for example, monkey wrench and wastebasket , originated in 19th century Britain. The adjectives mad meaning "angry", smart meaning "intelligent", and sick meaning "ill" are also more frequent in American (and Irish) English than British English. Linguist Bert Vaux created
13728-538: The United States and the United Kingdom suggest that, while spoken American English deviated away from period British English in many ways, it is conservative in a few other ways, preserving certain features 21st-century British English has since lost. Full rhoticity (or "R-fulness") is typical of American accents, pronouncing the phoneme /r/ (corresponding to the letter ⟨r⟩ ) in all environments, including in syllable-final position or before
13884-605: The West and Midwest, and New York Latino English , spoken in the New York metropolitan area . Additionally, ethnic varieties such as Yeshiva English and " Yinglish " are spoken by some American Orthodox Jews , Cajun Vernacular English by some Cajuns in southern Louisiana , and Pennsylvania Dutch English by some Pennsylvania Dutch people. American Indian Englishes have been documented among diverse Indian tribes. The island state of Hawaii , though primarily English-speaking,
14040-555: The accents spoken in the " Midland ": a vast band of the country that constitutes an intermediate dialect region between the traditional North and South. Western U.S. accents mostly fall under the General American spectrum. Below, ten major American English accents are defined by their particular combinations of certain vowel sounds: In 2010, William Labov noted that Great Lakes, Philadelphia, Pittsburgh, and West Coast accents have undergone "vigorous new sound changes" since
14196-405: The actual determined temperature at the poles. This error has been classified as the "equable climate problem". To solve this problem, the solution would involve finding a process to warm the poles without warming the tropics. Some hypotheses and tests which attempt to find the process are listed below. Due to the nature of water as opposed to land, less temperature variability would be present if
14352-410: The addition of a large lake was unable to reduce the seasonality to the levels shown by the floral and faunal data. The transport of heat from the tropics to the poles, much like how ocean heat transport functions in modern times, was considered a possibility for the increased temperature and reduced seasonality for the poles. With the increased sea surface temperatures and the increased temperature of
14508-505: The aeronautical sense ], gasoline ) as did certain automotive terms ( truck , trunk ). New foreign loanwords came with 19th and early 20th century European immigration to the U.S.; notably, from Yiddish ( chutzpah , schmooze, bupkis, glitch ) and German ( hamburger , wiener ). A large number of English colloquialisms from various periods are American in origin; some have lost their American flavor (from OK and cool to nerd and 24/7 ), while others have not ( have
14664-422: The amount of polar stratospheric clouds. While the polar stratospheric clouds could explain the reduction of the equator to pole temperature gradient and the increased temperatures at the poles during the early Eocene, there are a few drawbacks to maintaining polar stratospheric clouds for an extended period of time. Separate model runs were used to determine the sustainability of the polar stratospheric clouds. It
14820-456: The atmosphere during this period of time would have been from wetlands, swamps, and forests. The atmospheric methane concentration today is 0.000179% or 1.79 ppmv . As a result of the warmer climate and the sea level rise associated with the early Eocene, more wetlands, more forests, and more coal deposits would have been available for methane release. If we compare the early Eocene production of methane to current levels of atmospheric methane,
14976-528: The atmosphere may have been more important. Once the Antarctic region began to cool down, the ocean surrounding Antarctica began to freeze, sending cold water and icefloes north and reinforcing the cooling. The northern supercontinent of Laurasia began to fragment, as Europe , Greenland and North America drifted apart. In western North America, the Laramide Orogeny came to an end in
15132-524: The atmospheric carbon dioxide. This event was similar in magnitude to the massive release of greenhouse gasses at the beginning of the PETM, and it is hypothesized that the sequestration was mainly due to organic carbon burial and weathering of silicates. For the early Eocene there is much discussion on how much carbon dioxide was in the atmosphere. This is due to numerous proxies representing different atmospheric carbon dioxide content. For example, diverse geochemical and paleontological proxies indicate that at
15288-580: The beginning of the Eocene was about 27 degrees Celsius. The end is set at a major extinction event called the Grande Coupure (the "Great Break" in continuity) or the Eocene–Oligocene extinction event , which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay . As with other geologic periods , the strata that define the start and end of
15444-406: The country), though the vowel-consonant cluster found in "bird", "work", "hurt", "learn", etc. usually retains its r pronunciation, even in these non-rhotic American accents. Non-rhoticity among such speakers is presumed to have arisen from their upper classes' close historical contact with England, imitating London's r -dropping, a feature that has continued to gain prestige throughout England from
15600-413: The decline into an icehouse climate and the rapid expansion of the Antarctic ice sheet . The transition from a warming climate into a cooling climate began at around 49 Ma. Isotopes of carbon and oxygen indicate a shift to a global cooling climate. The cause of the cooling has been attributed to a significant decrease of >2,000 ppm in atmospheric carbon dioxide concentrations. One proposed cause of
15756-437: The deep ocean water during the early Eocene, one common hypothesis was that due to these increases there would be a greater transport of heat from the tropics to the poles. Simulating these differences, the models produced lower heat transport due to the lower temperature gradients and were unsuccessful in producing an equable climate from only ocean heat transport. While typically seen as a control on ice growth and seasonality,
15912-410: The deep ocean. On top of that, MECO warming caused an increase in the respiration rates of pelagic heterotrophs , leading to a decreased proportion of primary productivity making its way down to the seafloor and causing a corresponding decline in populations of benthic foraminifera. An abrupt decrease in lakewater salinity in western North America occurred during this warming interval. This warming
16068-421: The development of pecan was a change from wind-dispersed fruits to animal dispersion. This dispersal strategy coincides with developing a husk around the fruit and a drastic change in the relative concentrations of fatty acids. The ratio of oleic to linoleic acids is inverted between wind- and animal-dispersed seeds. Further differentiation from other species of Juglandaceae occurred about 44 million years ago during
16224-614: The diverse regional dialects of British English) became common after the mid-18th century, while at the same time speakers' identification with this new variety increased. Since the 18th century, American English has developed into some new varieties, including regional dialects that retain minor influences from waves of immigrant speakers of diverse languages, primarily European languages. Some racial and regional variation in American English reflects these groups' geographic settlement, their de jure or de facto segregation, and patterns in their resettlement. This can be seen, for example, in
16380-742: The double quotation mark ("like this") over the single ('as here'). Vocabulary differences vary by region. For example, autumn is used more commonly in the United Kingdom, whereas fall is more common in American English. Some other differences include: aerial (United Kingdom) vs. antenna, biscuit (United Kingdom) vs. cookie/cracker, car park (United Kingdom) vs. parking lot, caravan (United Kingdom) vs. trailer, city centre (United Kingdom) vs. downtown, flat (United Kingdom) vs. apartment, fringe (United Kingdom) vs. bangs, and holiday (United Kingdom) vs. vacation. AmE sometimes favors words that are morphologically more complex, whereas BrE uses clipped forms, such as AmE transportation and BrE transport or where
16536-411: The early Eocene would have produced triple the amount of methane. The warm temperatures during the early Eocene could have increased methane production rates, and methane that is released into the atmosphere would in turn warm the troposphere, cool the stratosphere, and produce water vapor and carbon dioxide through oxidation. Biogenic production of methane produces carbon dioxide and water vapor along with
16692-901: The early Eocene, although they became less abundant as the climate cooled. Dawn redwoods were far more extensive as well. The earliest definitive Eucalyptus fossils were dated from 51.9 Ma, and were found in the Laguna del Hunco deposit in Chubut province in Argentina . Cooling began mid-period, and by the end of the Eocene continental interiors had begun to dry, with forests thinning considerably in some areas. The newly evolved grasses were still confined to river banks and lake shores, and had not yet expanded into plains and savannas . The cooling also brought seasonal changes. Deciduous trees, better able to cope with large temperature changes, began to overtake evergreen tropical species. By
16848-639: The eastern coast of North America formed the Chesapeake Bay impact crater . The Tethys Ocean finally closed with the collision of Africa and Eurasia, while the uplift of the Alps isolated its final remnant, the Mediterranean , and created another shallow sea with island archipelagos to the north. Planktonic foraminifera in the northwestern Peri-Tethys are very similar to those of the Tethys in
17004-544: The end of the period, deciduous forests covered large parts of the northern continents, including North America, Eurasia and the Arctic, and rainforests held on only in equatorial South America , Africa , India and Australia . Antarctica began the Eocene fringed with a warm temperate to sub-tropical rainforest . Pollen found in Prydz Bay from the Eocene suggest taiga forest existed there. It became much colder as
17160-508: The enhanced burial of azolla could have had a significant effect on the world atmospheric carbon content and may have been the event to begin the transition into an ice house climate. The azolla event could have led to a draw down of atmospheric carbon dioxide of up to 470 ppm. Assuming the carbon dioxide concentrations were at 900 ppmv prior to the Azolla Event they would have dropped to 430 ppmv, or 30 ppmv more than they are today, after
17316-472: The enhanced carbon dioxide levels found in the early Eocene. The isolation of the Arctic Ocean, evidenced by euxinia that occurred at this time, led to stagnant waters and as the azolla sank to the sea floor, they became part of the sediments on the seabed and effectively sequestered the carbon by locking it out of the atmosphere for good. The ability for the azolla to sequester carbon is exceptional, and
17472-614: The epoch are well identified, though their exact dates are slightly uncertain. The term "Eocene" is derived from Ancient Greek Ἠώς ( Ēṓs ) meaning "Dawn", and καινός kainos meaning "new" or "recent", as the epoch saw the dawn of recent, or modern, life. Scottish geologist Charles Lyell (ignoring the Quaternary) divided the Tertiary Epoch into the Eocene, Miocene , Pliocene , and New Pliocene ( Holocene ) Periods in 1833. British geologist John Phillips proposed
17628-494: The expansion of the ice sheet was the creation of the Antarctic Circumpolar Current . The creation of the Antarctic circumpolar current would isolate the cold water around the Antarctic, which would reduce heat transport to the Antarctic along with creating ocean gyres that result in the upwelling of colder bottom waters. The issue with this hypothesis of the consideration of this being a factor for
17784-517: The following two centuries) when this ethnic group eventually made up one-seventh of the colonial population. Scotch-Irish settlers spread from Delaware and Pennsylvania throughout the larger Mid-Atlantic region, the inland regions of both the South and North, and throughout the West: American dialect areas that were all uninfluenced by upper-class non-rhoticity and that consequently have remained consistently rhotic. While non-rhoticity spread on
17940-549: The fruit of all other members of the hickory genus, is not truly a nut, but is technically a drupe , a fruit with a single stone or pit , surrounded by a husk. The husks are produced from the exocarp tissue of the flower, while the part known as the nut develops from the endocarp and contains the seed . The husk itself is aeneous, that is, brassy greenish-gold in color, oval to oblong in shape, 2.6–6 cm (1– 2 + 3 ⁄ 8 in) long, and 1.5–3 cm ( 5 ⁄ 8 – 1 + 1 ⁄ 8 in) broad. The outer husk
18096-405: The fruit, indicating they were referring to pecans. The Spaniards took the pecan into Europe, Asia, and Africa in the 16th century. In 1792, William Bartram reported in his botanical book, Travels , a nut tree, Juglans exalata that some botanists today argue was the American pecan tree. Still, others argue hickory , Carya ovata . Pecan trees are native to the United States, and writing about
18252-503: The health of a marine ecosystem)—one of the largest in the Cenozoic. This event happened around 55.8 Ma, and was one of the most significant periods of global change during the Cenozoic. The middle Eocene was characterized by the shift towards a cooler climate at the end of the EECO, around 47.8 Ma, which was briefly interrupted by another warming event called the middle Eocene climatic optimum (MECO). Lasting for about 400,000 years,
18408-399: The heat around the planet and keeping global temperatures high. When Australia split from the southern continent around 45 Ma, the warm equatorial currents were routed away from Antarctica. An isolated cold water channel developed between the two continents. However, modeling results call into question the thermal isolation model for late Eocene cooling, and decreasing carbon dioxide levels in
18564-944: The hospital , BrE to hospital ; contrast, however, AmE actress Elizabeth Taylor , BrE the actress Elizabeth Taylor ). Often, these differences are a matter of relative preferences rather than absolute rules; and most are not stable since the two varieties are constantly influencing each other, and American English is not a standardized set of dialects. Differences in orthography are also minor. The main differences are that American English usually uses spellings such as flavor for British flavour , fiber for fibre , defense for defence , analyze for analyse , license for licence , catalog for catalogue and traveling for travelling . Noah Webster popularized such spellings in America, but he did not invent most of them. Rather, "he chose already existing options on such grounds as simplicity, analogy or etymology." Other differences are due to
18720-674: The influence of 18th-century Protestant Ulster Scots immigrants (known in the U.S. as the Scotch-Irish ) in Appalachia developing Appalachian English and the 20th-century Great Migration bringing African-American Vernacular English to the Great Lakes urban centers. Any phonologically unmarked North American accent falls under an umbrella known as General American. This section mostly refers to such General American features. Studies on historical usage of English in both
18876-588: The initial stages of the opening of the Drake Passage ~38.5 Ma was not global, as evidenced by an absence of cooling in the North Atlantic. During the cooling period, benthic oxygen isotopes show the possibility of ice creation and ice increase during this later cooling. The end of the Eocene and beginning of the Oligocene is marked with the massive expansion of area of the Antarctic ice sheet that
19032-516: The largest omnivores. The first nimravids , including Dinictis , established themselves as amongst the first feliforms to appear. Their groups became highly successful and continued to live past the Eocene. Basilosaurus is a very well-known Eocene whale , but whales as a group had become very diverse during the Eocene, which is when the major transitions from being terrestrial to fully aquatic in cetaceans occurred. The first sirenians were evolving at this time, and would eventually evolve into
19188-438: The late 18th century onwards, but which has conversely lost prestige in the U.S. since at least the early 20th century. Non-rhoticity makes a word like car sound like cah or source like sauce . New York City and Southern accents are the most prominent regional accents of the country, as well as the most stigmatized and socially disfavored. Southern speech, strongest in southern Appalachia and certain areas of Texas,
19344-557: The late 19th century, most acreage of pecans grown today is of older cultivars, such as 'Stuart', 'Schley', 'Elliott', and 'Desirable', with known flaws, but also with known production potential. Cultivars such as 'Elliot' are increasing in popularity due to resistance to pecan scab . The long cycle time for pecan trees plus financial considerations dictate that new varieties go through an extensive vetting process before being widely planted. Numerous varieties produce well in Texas, but fail in
19500-556: The lower stratosphere at very low temperatures. Polar stratospheric clouds have a great impact on radiative forcing. Due to their minimal albedo properties and their optical thickness, polar stratospheric clouds act similar to a greenhouse gas and trap outgoing longwave radiation. Different types of polar stratospheric clouds occur in the atmosphere: polar stratospheric clouds that are created due to interactions with nitric or sulfuric acid and water (Type I) or polar stratospheric clouds that are created with only water ice (Type II). Methane
19656-610: The maximum of global warmth the atmospheric carbon dioxide values were at 700–900 ppm , while model simulations suggest a concentration of 1,680 ppm fits best with deep sea, sea surface, and near-surface air temperatures of the time. Other proxies such as pedogenic (soil building) carbonate and marine boron isotopes indicate large changes of carbon dioxide of over 2,000 ppm over periods of time of less than 1 million years. This large influx of carbon dioxide could be attributed to volcanic out-gassing due to North Atlantic rifting or oxidation of methane stored in large reservoirs deposited from
19812-530: The members of the new mammal orders were small, under 10 kg; based on comparisons of tooth size, Eocene mammals were only 60% of the size of the primitive Palaeocene mammals that preceded them. They were also smaller than the mammals that followed them. It is assumed that the hot Eocene temperatures favored smaller animals that were better able to manage the heat. Rodents were widespread. East Asian rodent faunas declined in diversity when they shifted from ctenodactyloid-dominant to cricetid–dipodid-dominant after
19968-480: The methane, as well as yielding infrared radiation. The breakdown of methane in an atmosphere containing oxygen produces carbon monoxide, water vapor and infrared radiation. The carbon monoxide is not stable, so it eventually becomes carbon dioxide and in doing so releases yet more infrared radiation. Water vapor traps more infrared than does carbon dioxide. At about the beginning of the Eocene Epoch (55.8–33.9 Ma)
20124-427: The mid-nineteenth century onwards, so they "are now more different from each other than they were 50 or 100 years ago", while other accents, like of New York City and Boston, have remained stable in that same time-frame. However, a General American sound system also has some debated degree of influence nationwide, for example, gradually beginning to oust the regional accent in urban areas of the South and at least some in
20280-569: The middle Lutetian but become completely disparate in the Bartonian, indicating biogeographic separation. Though the North Atlantic was opening, a land connection appears to have remained between North America and Europe since the faunas of the two regions are very similar. Eurasia was separated in three different landmasses 50 Ma; Western Europe, Balkanatolia and Asia. About 40 Ma, Balkanatolia and Asia were connected, while Europe
20436-399: The modern mammal orders appear within a brief period during the early Eocene . At the beginning of the Eocene, several new mammal groups arrived in North America. These modern mammals, like artiodactyls , perissodactyls , and primates , had features like long, thin legs , feet, and hands capable of grasping, as well as differentiated teeth adapted for chewing. Dwarf forms reigned. All
20592-617: The most formal contexts, and regional accents with the most General American native features include North Midland, Western New England, and Western accents. Although no longer region-specific, African-American Vernacular English , which remains the native variety of most working- and middle-class African Americans , has a close relationship to Southern dialects and has greatly influenced everyday speech of many Americans, including hip hop culture . Hispanic and Latino Americans have also developed native-speaker varieties of English. The best-studied Latino Englishes are Chicano English , spoken in
20748-664: The ocean. Recent analysis of and research into these hyperthermals in the early Eocene has led to hypotheses that the hyperthermals are based on orbital parameters, in particular eccentricity and obliquity. The hyperthermals in the early Eocene, notably the Palaeocene–Eocene Thermal Maximum (PETM), the Eocene Thermal Maximum 2 (ETM2), and the Eocene Thermal Maximum 3 (ETM3), were analyzed and found that orbital control may have had
20904-416: The orbital parameters were theorized as a possible control on continental temperatures and seasonality. Simulating the Eocene by using an ice free planet, eccentricity , obliquity , and precession were modified in different model runs to determine all the possible different scenarios that could occur and their effects on temperature. One particular case led to warmer winters and cooler summer by up to 30% in
21060-402: The past forms of a few verbs (for example, AmE/BrE: learned / learnt , burned / burnt , snuck/sneaked , dove/dived ) although the purportedly "British" forms can occasionally be seen in American English writing as well; different prepositions and adverbs in certain contexts (for example, AmE in school, BrE at school ); and whether or not a definite article is used, in very few cases (AmE to
21216-518: The pecan tree goes back to the nation's founders. Thomas Jefferson planted pecan trees, C. illinoinensis (Illinois nuts), in his nut orchard at his home, Monticello , in Virginia . George Washington reported in his journal that Thomas Jefferson gave him "Illinois nuts", pecans, which Washington then grew at Mount Vernon , his Virginia home. Commercial production of pecans was slow because trees were slow to mature and bear fruit. More importantly,
21372-416: The period progressed; the heat-loving tropical flora was wiped out, and by the beginning of the Oligocene, the continent hosted deciduous forests and vast stretches of tundra . During the Eocene, plants and marine faunas became quite modern. Many modern bird orders first appeared in the Eocene. The Eocene oceans were warm and teeming with fish and other sea life. The oldest known fossils of most of
21528-438: The polar stratospheric clouds effects on the Eocene climate, models were run comparing the effects of polar stratospheric clouds at the poles to an increase in atmospheric carbon dioxide. The polar stratospheric clouds had a warming effect on the poles, increasing temperatures by up to 20 °C in the winter months. A multitude of feedbacks also occurred in the models due to the polar stratospheric clouds' presence. Any ice growth
21684-458: The reduction in carbon dioxide during the warming to cooling transition was the azolla event . With the equable climate during the early Eocene, warm temperatures in the arctic allowed for the growth of azolla , which is a floating aquatic fern, on the Arctic Ocean . The significantly high amounts of carbon dioxide also acted to facilitate azolla blooms across the Arctic Ocean. Compared to current carbon dioxide levels, these azolla grew rapidly in
21840-459: The region. One possible cause of atmospheric carbon dioxide increase could have been a sudden increase due to metamorphic release due to continental drift and collision of India with Asia and the resulting formation of the Himalayas ; however, data on the exact timing of metamorphic release of atmospheric carbon dioxide is not well resolved in the data. Recent studies have mentioned, however, that
21996-445: The removal of the ocean between Asia and India could have released significant amounts of carbon dioxide. Another hypothesis still implicates a diminished negative feedback of silicate weathering as a result of continental rocks having become less weatherable during the warm Early and Middle Eocene, allowing volcanically released carbon dioxide to persist in the atmosphere for longer. Yet another explanation hypothesises that MECO warming
22152-554: The state's official pie. The town of San Saba, Texas claims to be "The Pecan Capital of the World" and is the site of the "Mother Tree" ( c. 1850 ) considered to be the source of the state's production through its progeny. Alabama named the pecan the official state nut in 1982. Arkansas adopted it as the official nut in 2009. California adopted it, along with the almond , pistachio , and walnut , as one of four state nuts in 2017. Louisiana , known for pralines , adopted
22308-570: The traditional standard accent of (southern) England, Received Pronunciation (RP), has evolved a trap–bath split . Moreover, American accents preserve /h/ at the start of syllables, while perhaps a majority of the regional dialects of England participate in /h/ dropping , particularly in informal contexts. However, General American is also innovative in a number of its own ways: The process of coining new lexical items started as soon as English-speaking British-American colonists began borrowing names for unfamiliar flora, fauna, and topography from
22464-399: The trees grown from the nuts of one tree have very diverse characters. To speed nut production and retain the best tree characteristics, grafting from mature, productive trees was the apparent strategy. However, this proved technically challenging. The Centennial cultivar was the first to be successfully grafted. This was accomplished by an enslaved person called Antoine in 1846 or 1847, who
22620-399: The tropics that would require much higher average temperatures to sustain them. TEX 86 BAYSPAR measurements indicate extremely high sea surface temperatures of 40 °C (104 °F) to 45 °C (113 °F) at low latitudes, although clumped isotope analyses point to a maximum low latitude sea surface temperature of 36.3 °C (97.3 °F) ± 1.9 °C (35.4 °F) during
22776-417: The verb-and-preposition combination: stopover, lineup, tryout, spin-off, shootout , holdup, hideout, comeback, makeover , and many more. Some prepositional and phrasal verbs are in fact of American origin ( win out, hold up, back up/off/down/out, face up to and many others). Noun endings such as -ee (retiree), -ery (bakery), -ster (gangster) and -cian (beautician) are also particularly productive in
22932-775: The word corn , used in England to refer to wheat (or any cereal), came to denote the maize plant, the most important crop in the U.S. Most Mexican Spanish contributions came after the War of 1812 , with the opening of the West, like ranch (now a common house style ). Due to Mexican culinary influence, many Spanish words are incorporated in general use when talking about certain popular dishes: cilantro (instead of coriander), queso, tacos, quesadillas, enchiladas, tostadas, fajitas, burritos, and guacamole. These words usually lack an English equivalent and are found in popular restaurants. New forms of dwelling created new terms ( lot , waterfront) and types of homes like log cabin , adobe in
23088-463: The world became more arid and cold over the course of the stage, such as the Fushun Basin. In East Asia, lake level changes were in sync with global sea level changes over the course of the MLEC. Global cooling continued until there was a major reversal from cooling to warming in the Bartonian. This warming event, signifying a sudden and temporary reversal of the cooling conditions, is known as
23244-528: Was a major step into the icehouse climate. Multiple proxies, such as oxygen isotopes and alkenones , indicate that at the Eocene–Oligocene transition, the atmospheric carbon dioxide concentration had decreased to around 750–800 ppm, approximately twice that of present levels . Along with the decrease of atmospheric carbon dioxide reducing the global temperature, orbital factors in ice creation can be seen with 100,000-year and 400,000-year fluctuations in benthic oxygen isotope records. Another major contribution to
23400-476: Was caused by the simultaneous occurrence of minima in both the 400 kyr and 2.4 Myr eccentricity cycles. During the MECO, sea surface temperatures in the Tethys Ocean jumped to 32–36 °C, and Tethyan seawater became more dysoxic. A decline in carbonate accumulation at ocean depths of greater than three kilometres took place synchronously with the peak of the MECO, signifying ocean acidification took place in
23556-465: Was connected 34 Ma. The Fushun Basin contained large, suboxic lakes known as the paleo-Jijuntun Lakes. India collided with Asia , folding to initiate formation of the Himalayas . The incipient subcontinent collided with the Kohistan–Ladakh Arc around 50.2 Ma and with Karakoram around 40.4 Ma, with the final collision between Asia and India occurring ~40 Ma. The Eocene Epoch contained
23712-402: Was determined that in order to maintain the lower stratospheric water vapor, methane would need to be continually released and sustained. In addition, the amounts of ice and condensation nuclei would need to be high in order for the polar stratospheric cloud to sustain itself and eventually expand. The Eocene is not only known for containing the warmest period during the Cenozoic; it also marked
23868-810: Was owned by Jacques Telesphore Roman of the Oak Alley Plantation near the Mississippi River. The scions were supplied by Dr. A. E. Colomb, who had unsuccessfully attempted to graft them. Pecan is a 32-chromosome species (1N = 16) that readily hybridizes with other 32-chromosome members of the Carya genus, such as Carya ovata , Carya laciniosa , Carya cordiformis and has been reported to hybridize with 64-chromosome species such as Carya tomentosa . Most such hybrids are unproductive. Hybrids are referred to as " hicans " to indicate their hybrid origin. Recent efforts at NMSU to complete
24024-401: Was present on Earth with a smaller difference in temperature from the equator to the poles . Because of this the maximum sea level was 150 meters higher than current levels. Following the maximum was a descent into an icehouse climate from the Eocene Optimum to the Eocene–Oligocene transition at 34 Ma. During this decrease, ice began to reappear at the poles, and the Eocene–Oligocene transition
24180-437: Was slowed immensely and would lead to any present ice melting. Only the poles were affected with the change in temperature and the tropics were unaffected, which with an increase in atmospheric carbon dioxide would also cause the tropics to increase in temperature. Due to the warming of the troposphere from the increased greenhouse effect of the polar stratospheric clouds, the stratosphere would cool and would potentially increase
24336-469: Was written by Noah Webster in 1828, codifying several of these spellings. Differences in grammar are relatively minor, and do not normally affect mutual intelligibility; these include: typically a lack of differentiation between adjectives and adverbs, employing the equivalent adjectives as adverbs he ran quick / he ran quickly ; different use of some auxiliary verbs ; formal (rather than notional) agreement with collective nouns ; different preferences for
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