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117-627: The Ordovician, named after the Welsh tribe of the Ordovices , was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison , who were placing the same rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed strata were different from those of either

234-599: A dense rock equivalent volume of as much as 1,140 cubic kilometres (270 cu mi). Remarkably, this appears to have had little impact on life. There was vigorous tectonic activity along northwest margin of Gondwana during the Floian, 478 Ma, recorded in the Central Iberian Zone of Spain. The activity reached as far as Turkey by the end of Ordovician. The opposite margin of Gondwana, in Australia, faced

351-576: A "plausible vector for the spread of early Celtic languages into Britain". There was much less migration into Britain during the subsequent Iron Age, so it is more likely that Celtic reached Britain before then. Barry Cunliffe suggests that a branch of Celtic was already being spoken in Britain and that the Bronze Age migration introduced the Brittonic branch. The Anglo-Saxon Chronicle , which

468-528: A bard . The medieval Welsh form of Latin Britanni was Brython (singular and plural). Brython was introduced into English usage by John Rhys in 1884 as a term unambiguously referring to the P-Celtic speakers of Great Britain, to complement Goidel ; hence the adjective Brythonic refers to the group of languages. " Brittonic languages " is a more recent coinage (first attested in 1923 according to

585-598: A biogeographic affinity with Gondwana, and the Alborz margin of Gondwana was linked biogeographically to South China. Southeast Asia's fauna also maintained strong affinities to Gondwana's. North China was biogeographically connected to Laurentia and the Argentinian margin of Gondwana. A Celtic biogeographic province also existed, separate from the Laurentian and Baltican ones. However, tropical articulate brachiopods had

702-466: A burst of volcanic activity that deposited new silicate rocks, which draw CO 2 out of the air as they erode. Another possibility is that bryophytes and lichens, which colonized land in the middle to late Ordovician, may have increased weathering enough to draw down CO 2 levels. The drop in CO 2 selectively affected the shallow seas where most organisms lived. It has also been suggested that shielding of

819-589: A deep embayment between Siberia and the Central Mongolian terranes . Most of the terranes of central Asia were part of an equatorial archipelago whose geometry is poorly constrained by the available evidence. The period was one of extensive, widespread tectonism and volcanism. However, orogenesis (mountain-building) was not primarily due to continent-continent collisions. Instead, mountains arose along active continental margins during accretion of arc terranes or ribbon microcontinents. Accretion of new crust

936-640: A distinct Brittonic culture and language. Britonia in Spanish Galicia seems to have disappeared by 900 AD. Wales and Brittany remained independent for a considerable time, however, with Brittany united with France in 1532, and Wales united with England by the Laws in Wales Acts 1535–1542 in the mid 16th century during the rule of the Tudors (Y Tuduriaid), who were themselves of Welsh heritage on

1053-605: A distinct band around the Earth, and that the breakup of the parent body may have formed a ring system for a period of about 40 million years, with frequent falling debris causing these craters. The Ordovician 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, and invertebrate faunas with dominantly calcitic skeletons. Biogenic aragonite , like that composing

1170-548: A geological history from later in the early Cambrian until the mid-Orodovician. Subduction evolved along the shores of Gondwana, which caused Avalonia to rift away and begin its northbound journey towards Baltica during late Cambrian and Early Ordovician. The Rheic Ocean opened behind the Avalonian microcontinents. This independent movement of Avalonia started from a latitude of about 60° South. The eastern end of Avalonia collided with Baltica at 30°S, an event which closed

1287-462: A given landmass were severely affected. Tropical lifeforms were hit particularly hard in the first wave of extinction, while cool-water species were hit worst in the second pulse. Those species able to adapt to the changing conditions survived to fill the ecological niches left by the extinctions. For example, there is evidence the oceans became more deeply oxygenated during the glaciation, allowing unusual benthic organisms (Hirnantian fauna) to colonize

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1404-689: A more cosmopolitan distribution , with less diversity on different continents. During the Middle Ordovician, beta diversity began a significant decline as marine taxa began to disperse widely across space. Faunas become less provincial later in the Ordovician, partly due to the narrowing of the Iapetus Ocean, though they were still distinguishable into the late Ordovician. Trilobites in particular were rich and diverse, and experienced rapid diversification in many regions. Trilobites in

1521-458: A profound genetic impact. Avalonia Avalonia was a microcontinent in the Paleozoic era . Crustal fragments of this former microcontinent underlie south-west Great Britain , southern Ireland , and the eastern coast of North America . It is the source of many of the older rocks of Western Europe , Atlantic Canada , and parts of the coastal United States . Avalonia is named for

1638-535: A set of island arcs. The accretion of these arcs to the eastern margin of Gondwana was responsible for the Benambran Orogeny of eastern Australia. Subduction also took place along what is now Argentina (Famatinian Orogeny) at 450 Ma. This involved significant back arc rifting. The interior of Gondwana was tectonically quiet until the Triassic . Towards the end of the period, Gondwana began to drift across

1755-789: A single tectonic unit. Avalonia is the largest of the peri-Gondwanan terranes, a series of continental blocks that more or less simultaneously broke off the margins of the southern supercontinent Gondwana and therefore share an early Paleozoic marine fauna. They were pulled northward and eventually collided to form the Appalachian , Caledonide , and Variscan orogens . West Avalonia, in North America, stretches from New England to Atlantic Canada, and East Avalonia, in Europe, from southern Britain to Brabant. Other Peri-Gondwanan terranes, sometimes called "Greater Avalonia", include Carolina in

1872-611: A sub-kingdom of Calchwynedd may have clung on in the Chilterns for a time. Novant , which occupied Galloway and Carrick, was soon subsumed by fellow Brittonic-Pictish polities by 700 AD. Aeron , which encompassed modern Ayrshire , was conquered by the Anglo-Saxon kingdom of Northumbria by 700 AD. Some Brittonic kingdoms were able to successfully resist these incursions: Rheged (encompassing much of modern Northumberland and County Durham and areas of southern Scotland and

1989-489: Is marked by a sudden abundance of hard substrate trace fossils such as Trypanites , Palaeosabella , Petroxestes and Osprioneides . Bioerosion became an important process, particularly in the thick calcitic skeletons of corals, bryozoans and brachiopods, and on the extensive carbonate hardgrounds that appear in abundance at this time. Green algae were common in the Late Cambrian (perhaps earlier) and in

2106-420: Is poorly known, but, based on isotopic analyses , proto-Avalonia most likely evolved together with Carolina about 800 Ma from volcanic arcs far offshore from the supercontinent Rodinia , most likely outboard continental terranes of more obvious West African affinities, such as Cadomia and Iberia . About 650 Ma the Avalonian belt collided with Gondwana. Avalonia originally developed along

2223-648: The Oxford English Dictionary ). In the early Middle Ages , following the Anglo-Saxon settlement of Britain , the Anglo-Saxons called all Britons Bryttas or Wealas (Welsh), while they continued to be called Britanni or Brittones in Medieval Latin . From the 11th century, they are more often referred to separately as the Welsh , Cumbrians , Cornish , and Bretons , as they had separate political histories from then. From

2340-582: The Acadian orogeny . In the Carboniferous , the new continent and another terrane, Armorica which included Iberia , drifted in from Gondwana, trapping Avalonia between it and the continent so adding Iberia/Armorica to Euramerica. This was followed up by the arrival of Gondwana. The effects of these collisions are seen in Europe as the Variscan folding . In North America it shows as later phases of

2457-656: The Ardennes of Belgium and north-eastern France, north Germany, north-western Poland, south-eastern Ireland, and the south-western edge of the Iberian Peninsula . Part of the British-Belgian section formed an island in the Carboniferous, affecting the disposition of coalfields; this is known by names such as the ' London-Brabant Island '. Its bulk had an effect on the geological structure between

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2574-634: The Avalon Peninsula in Newfoundland . Avalonia developed as a volcanic arc on the northern margin of Gondwana . It eventually rifted off, becoming a drifting microcontinent. The Rheic Ocean formed behind it, and the Iapetus Ocean shrank in front. It collided with the continents Baltica , then Laurentia , and finally with Gondwana, ending up in the interior of Pangea . When Pangea broke up, Avalonia's remains were divided by

2691-534: The British Isles , particularly Welsh people , suggesting genetic continuity between Iron Age Britain and Roman Britain, and partial genetic continuity between Roman Britain and modern Britain. On the other hand, they were genetically substantially different from the examined Anglo-Saxon individual and modern English populations of the area, suggesting that the Anglo-Saxon settlement of Britain left

2808-586: The Channel Islands . There they set up their own small kingdoms and the Breton language developed from Brittonic Insular Celtic rather than Gaulish or Frankish . A further Brittonic colony, Britonia , was also set up at this time in Gallaecia in northwestern Spain . Many of the old Brittonic kingdoms began to disappear in the centuries after the Anglo-Saxon and Scottish Gaelic invasions; Parts of

2925-670: The Farne Islands fell to the Anglo-Saxons in 559 AD and Deira became an Anglo-Saxon kingdom after this point. Caer Went had officially disappeared by 575 AD becoming the Anglo-Saxon kingdom of East Anglia . Gwent was only partly conquered; its capital Caer Gloui ( Gloucester ) was taken by the Anglo-Saxons in 577 AD, handing Gloucestershire and Wiltshire to the invaders, while the westernmost part remained in Brittonic hands, and continued to exist in modern Wales. Caer Lundein , encompassing London , St. Albans and parts of

3042-949: The Hirnantian . The Ashgill Epoch, the last epoch of the British Ordovician, is made of four ages: the Hirnantian Age, the Rawtheyan Age, the Cautleyan Age, and the Pusgillian Age. These ages make up the time period from c. 450 Ma to c. 443 Ma. The Rawtheyan, the second last of the Ashgill ages, was from c. 449 Ma to c. 445 Ma. It is in the Katian Age of the ICS's Geologic Time Scale . During

3159-597: The Home Counties , fell from Brittonic hands by 600 AD, and Bryneich, which existed in modern Northumbria and County Durham with its capital of Din Guardi (modern Bamburgh ) and which included Ynys Metcaut ( Lindisfarne ), had fallen by 605 AD becoming Anglo-Saxon Bernicia. Caer Celemion (in modern Hampshire and Berkshire) had fallen by 610 AD. Elmet, a large kingdom that covered much of modern Yorkshire, Lancashire, and Cheshire and likely had its capital at modern Leeds,

3276-639: The ICS erected a formal international system of subdivisions for the Ordovician Period and System. Pre-existing Baltoscandic, British, Siberian, North American, Australian, Chinese, Mediterranean and North- Gondwanan regional stratigraphic schemes are also used locally. The Ordovician Period in Britain was traditionally broken into Early (Tremadocian and Arenig ), Middle ( Llanvirn (subdivided into Abereiddian and Llandeilian) and Llandeilo ) and Late ( Caradoc and Ashgill) epochs. The corresponding rocks of

3393-806: The Old English of the Anglo-Saxons, and Scottish Gaelic , although this was likely a gradual process in many areas. Similarly, the Brittonic colony of Britonia in northwestern Spain appears to have disappeared soon after 900 AD. The kingdom of Ystrad Clud (Strathclyde) was a large and powerful Brittonic kingdom of the Hen Ogledd (the 'Old North') which endured until the end of the 11th century, successfully resisting Anglo-Saxon, Gaelic Scots and later also Viking attacks. At its peak it encompassed modern Strathclyde, Dumbartonshire , Cumbria , Stirlingshire , Lanarkshire , Ayrshire , Dumfries and Galloway , Argyll and Bute , and parts of North Yorkshire ,

3510-694: The Pretanoí or Bretanoí . Pliny 's Natural History (77 AD) says the older name for the island was Albion , and Avienius calls it insula Albionum , "island of the Albions". The name could have reached Pytheas from the Gauls . The Latin name for the Britons was Britanni . The P-Celtic ethnonym has been reconstructed as * Pritanī , from Common Celtic * kʷritu , which became Old Irish cruth and Old Welsh pryd . This likely means "people of

3627-696: The Rheic Ocean between Gondwana and Avalonia. Avalonia collided with Baltica towards the end of Ordovician. Other geographic features of the Ordovician world included the Tornquist Sea , which separated Avalonia from Baltica; the Aegir Ocean, which separated Baltica from Siberia; and an oceanic area between Siberia, Baltica, and Gondwana which expanded to become the Paleoasian Ocean in Carboniferous time. The Mongol-Okhotsk Ocean formed

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3744-779: The Scottish Borders ) survived well into the 8th century AD, before the eastern part peacefully joined with the Anglo-Saxon kingdom of Bernicia – Northumberland by 730 AD, and the west was taken over by the fellow Britons of Ystrad Clud . Similarly, the kingdom of Gododdin , which appears to have had its court at Din Eidyn (modern Edinburgh ) and encompassed parts of modern Northumbria , County Durham , Lothian and Clackmannanshire , endured until approximately 775 AD before being divided by fellow Brittonic Picts, Gaelic Scots and Anglo-Saxons. The Kingdom of Cait , covering modern Caithness , Sutherland , Orkney , and Shetland ,

3861-870: The Tornquist Sea , during the Late Ordovician. In Avalonia, folding, faulting, and volcanism followed – as evidenced in the Welsh Borderland and the Taconic deformation in Laurentia ;– some or all of which are related to the collision. Plinian eruptions resulted from the subduction beneath Avalonia and produced thick layers of K-bentonite in southwestern Baltica, while the Millbrig eruptions occurred in Laurentia. This Late Ordovician magmatism peaked between 457 and 449 Ma. In

3978-405: The endocerid cephalopods died out completely, except for possible rare Silurian forms. The Ordovician–Silurian extinction events may have been caused by an ice age that occurred at the end of the Ordovician Period, due to the expansion of the first terrestrial plants , as the end of the Late Ordovician was one of the coldest times in the last 600 million years of Earth's history. On the whole,

4095-611: The indigenous Celtic people who inhabited Great Britain from at least the British Iron Age until the High Middle Ages , at which point they diverged into the Welsh , Cornish , and Bretons (among others). They spoke Common Brittonic , the ancestor of the modern Brittonic languages . The earliest written evidence for the Britons is from Greco-Roman writers and dates to the Iron Age. Ancient Britain

4212-588: The 20th century. Celtic Britain was made up of many territories controlled by Brittonic tribes . They are generally believed to have dwelt throughout the whole island of Great Britain , at least as far north as the Clyde – Forth isthmus . The territory north of this was largely inhabited by the Picts ; little direct evidence has been left of the Pictish language , but place names and Pictish personal names recorded in

4329-480: The 2nd century AD and the 4th century AD during the period of Roman Britain . Six of these individuals were identified as native Britons. The six examined native Britons all carried types of the paternal R1b1a2a1a and carried the maternal haplogroups H6a1a , H1bs , J1c3e2 , H2 , H6a1b2 and J1b1a1 . The indigenous Britons of Roman Britain were genetically closely related to the earlier Iron Age female Briton, and displayed close genetic links to modern Celts of

4446-623: The Acadian orogeny. This was happening at around the Equator during the later Carboniferous, forming Pangaea with Avalonia near its centre but partially flooded by shallow sea. In the Jurassic , Pangaea split into Laurasia and Gondwana, with Avalonia as part of Laurasia. In the Cretaceous , Laurasia broke up into North America and Eurasia with Avalonia split between them. Iberia

4563-599: The Ancient British seem to have had generally similar cultural practices to the Celtic cultures nearest to them on the continent. There are significant differences in artistic styles, and the greatest period of what is known as the "Insular La Tène" style, surviving mostly in metalwork, was in the century or so before the Roman conquest, and perhaps the decades after it. The carnyx , a trumpet with an animal-headed bell,

4680-864: The Appalachian and the deep bedrock of Florida in North America, Oaxaquia and Yucatán in Mexico, and the Chortis Block in Central America. The North American terranes of Ganderia and Carolinia are sometimes grouped with Avalonia because they were transferred together across the Iapetus Ocean. Sometimes the Meguma terrane in Nova Scotia is also included. The Avalonian part of Great Britain almost exactly coincides with England and Wales. Elsewhere in Europe, parts of Avalonia are found in

4797-451: The Ardennes and the English Midlands by influencing the subsequent crustal folding resulting from the Variscan collision. In Canada, Avalonia comprises the Avalon Peninsula of southeast Newfoundland , southern New Brunswick , part of Nova Scotia , and Prince Edward Island . In the United States, Avalonia consists of northern coastal Maine , all of Rhode Island , and other sections of coastal New England . The basement of Avalonia

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4914-399: The British Isles after arriving from the continent in the 7th century BC. The language eventually began to diverge; some linguists have grouped subsequent developments as Western and Southwestern Brittonic languages . Western Brittonic developed into Welsh in Wales and the Cumbric language in the Hen Ogledd or "Old North" of Britain (modern northern England and southern Scotland), while

5031-414: The Britons and Caledonians in the north remained unconquered and Hadrian's Wall became the edge of the empire. A Romano-British culture emerged, mainly in the southeast, and British Latin coexisted with Brittonic. It is unclear what relationship the Britons had with the Picts , who lived outside of the empire in northern Britain, however, most scholars today accept the fact that the Pictish language

5148-409: The Brittonic state of Kernow . The Channel Islands (colonised by Britons in the 5th century) came under attack from Norse and Danish Viking attack in the early 9th century AD, and by the end of that century had been conquered by Viking invaders. The Kingdom of Ce , which encompassed modern Marr , Banff , Buchan , Fife , and much of Aberdeenshire , disappeared soon after 900 AD. Fortriu ,

5265-400: The Cambrian or even the Ediacaran , became common and varied, especially bivalves , gastropods , and nautiloid cephalopods. Cephalopods diversified from shallow marine tropical environments to dominate almost all marine environments. Graptolites, which evolved in the preceding Cambrian period, thrived in the oceans. This includes the distinctive Nemagraptus gracilis graptolite fauna, which

5382-403: The Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Geological Congress . Life continued to flourish during the Ordovician as it had in the earlier Cambrian Period, although the end of the period

5499-414: The Cambrian were succeeded by those that dominated the rest of the Paleozoic, such as articulate brachiopods, cephalopods , and crinoids . Articulate brachiopods, in particular, largely replaced trilobites in shelf communities. Their success epitomizes the greatly increased diversity of carbonate shell-secreting organisms in the Ordovician compared to the Cambrian. Ordovician geography had its effect on

5616-435: The Cumbrians of the Hen Ogledd ("Old North") in southern Scotland and northern England, and the remnants of the Pictish people in northern Scotland. Common Brittonic developed into the distinct Brittonic languages: Welsh , Cumbric , Cornish and Breton . In Celtic studies , 'Britons' refers to native speakers of the Brittonic languages in the ancient and medieval periods, "from the first evidence of such speech in

5733-558: The Early Eocene Climatic Optimum. Carbon dioxide levels were very high at the Ordovician period's beginning. By the late Early Ordovician, the Earth cooled, giving way to a more temperate climate in the Middle Ordovician, with the Earth likely entering the Early Palaeozoic Ice Age during the Sandbian, and possibly as early as the Darriwilian or even the Floian. The Dapingian and Sandbian saw major humidification events evidenced by trace metal concentrations in Baltoscandia from this time. Evidence suggests that global temperatures rose briefly in

5850-405: The Early Ordovician, leveling off somewhat during the middle of the period. Locally, some regressions occurred, but the sea level rise continued in the beginning of the Late Ordovician. Sea levels fell steadily due to the cooling temperatures for about 3 million years leading up to the Hirnantian glaciation. During this icy stage, sea level seems to have risen and dropped somewhat. Despite much study,

5967-455: The Great Ordovician Biodiversification Event) was no less remarkable; marine faunal genera increased fourfold, resulting in 12% of all known Phanerozoic marine fauna. Several animals also went through a miniaturization process, becoming much smaller than their Cambrian counterparts. Another change in the fauna was the strong increase in filter-feeding organisms. The trilobite, inarticulate brachiopod, archaeocyathid , and eocrinoid faunas of

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6084-437: The Hirnantian glaciation. As with North America and Europe , Gondwana was largely covered with shallow seas during the Ordovician. Shallow clear waters over continental shelves encouraged the growth of organisms that deposit calcium carbonates in their shells and hard parts. The Panthalassic Ocean covered much of the Northern Hemisphere , and other minor oceans included Proto-Tethys , Paleo-Tethys , Khanty Ocean , which

6201-406: The Iron Age individuals were markedly different from later Anglo-Saxon samples, who were closely related to Danes and Dutch people . Martiano et al. (2016) examined the remains of a female Iron Age Briton buried at Melton between 210 BC and 40 AD. She was found to be carrying the maternal haplogroup U2e1e . The study also examined seven males buried in Driffield Terrace near York between

6318-494: The Isles of Scilly and Brittany are Brittonic, and Brittonic family and personal names remain common. During the 19th century, many Welsh farmers migrated to Patagonia in Argentina , forming a community called Y Wladfa , which today consists of over 1,500 Welsh speakers. In addition, a Brittonic legacy remains in England, Scotland and Galicia in Spain, in the form of often large numbers of Brittonic place and geographical names. Examples of geographical Brittonic names survive in

6435-402: The Late Ordovician argues that the mass extinction was a single protracted episode lasting several hundred thousand years, with abrupt changes in water depth and sedimentation rate producing two pulses of last occurrences of species. Celtic Britons The Britons ( * Pritanī , Latin : Britanni , Welsh : Brythoniaid ), also known as Celtic Britons or Ancient Britons , were

6552-414: The Ordovician System are referred to as coming from the Lower, Middle, or Upper part of the column. The Tremadoc corresponds to the ICS's Tremadocian. The Arenig corresponds to the Floian, all of the Dapingian and the early Darriwilian. The Llanvirn corresponds to the late Darriwilian. The Caradoc covers the Sandbian and the first half of the Katian. The Ashgill represents the second half of the Katian, plus

6669-407: The Ordovician of Wisconsin have been found with an age of about 460 million years ago, a time when the land flora most likely only consisted of plants similar to non-vascular bryophytes . Though stromatolites had declined from their peak in the Proterozoic, they continued to exist in localised settings. The Ordovician came to a close in a series of extinction events that, taken together, comprise

6786-421: The Ordovician were very different from their predecessors in the Cambrian. Many trilobites developed bizarre spines and nodules to defend against predators such as primitive eurypterids and nautiloids while other trilobites such as Aeglina prisca evolved to become swimming forms. Some trilobites even developed shovel-like snouts for ploughing through muddy sea bottoms. Another unusual clade of trilobites known as

6903-714: The Ordovician, the southern continents were assembled into Gondwana , which reached from north of the equator to the South Pole . The Panthalassic Ocean, centered in the northern hemisphere, covered over half the globe. At the start of the period, the continents of Laurentia (in present-day North America ), Siberia , and Baltica (present-day northern Europe) were separated from Gondwana by over 5,000 kilometres (3,100 mi) of ocean. These smaller continents were also sufficiently widely separated from each other to develop distinct communities of benthic organisms. The small continent of Avalonia had just rifted from Gondwana and began to move north towards Baltica and Laurentia, opening

7020-434: The Ordovician, when at least two volcanic island arcs collided with Laurentia to form the Appalachian Mountains . Laurentia was otherwise tectonically stable. An island arc accreted to South China during the period, while subduction along north China (Sulinheer) resulted in the emplacement of ophiolites. The ash fall of the Millburg/Big Bentonite bed, at about 454 Ma, was the largest in the last 590 million years. This had

7137-425: The Ordovician. The ice age was possibly not long-lasting. Oxygen isotopes in fossil brachiopods show its duration may have been only 0.5 to 1.5 million years. Other researchers (Page et al.) estimate more temperate conditions did not return until the late Silurian. The late Ordovician glaciation event was preceded by a fall in atmospheric carbon dioxide (from 7000 ppm to 4400 ppm). The dip may have been caused by

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7254-555: The Ordovician. Terrestrial plants probably evolved from green algae, first appearing as tiny non- vascular forms resembling liverworts , in the middle to late Ordovician. Fossil spores found in Ordovician sedimentary rock are typical of bryophytes. Among the first land fungi may have been arbuscular mycorrhiza fungi ( Glomerales ), playing a crucial role in facilitating the colonization of land by plants through mycorrhizal symbiosis , which makes mineral nutrients available to plant cells; such fossilized fungal hyphae and spores from

7371-417: The Roman Empire invaded Britain. The British tribes opposed the Roman legions for many decades, but by 84 AD the Romans had decisively conquered southern Britain and had pushed into Brittonic areas of what would later become northern England and southern Scotland. During the same period, Belgic tribes from the Gallic-Germanic borderlands settled in southern Britain. Caesar asserts the Belgae had first crossed

7488-416: The South Pole. This contributed to the Hibernian glaciation and the associated extinction event. The Ordovician meteor event is a proposed shower of meteors that occurred during the Middle Ordovician Epoch, about 467.5 ± 0.28 million years ago, due to the break-up of the L chondrite parent body. It is not associated with any major extinction event. A 2024 study found that craters from this event cluster in

7605-415: The Southwestern dialect became Cornish in Cornwall and South West England and Breton in Armorica. Pictish is now generally accepted to descend from Common Brittonic, rather than being a separate Celtic language. Welsh and Breton survive today; Cumbric and Pictish became extinct in the 12th century. Cornish had become extinct by the 19th century but has been the subject of language revitalization since

7722-445: The Wuliuan, exploded in diversity during the Tremadocian, quickly becoming globally widespread. Several groups of endobiotic symbionts appeared in the Ordovician. In the Early Ordovician, trilobites were joined by many new types of organisms, including tabulate corals, strophomenid , rhynchonellid , and many new orthid brachiopods, bryozoans, planktonic graptolites and conodonts, and many types of molluscs and echinoderms, including

7839-434: The ancestry of subsequent Iron Age people in this area, but not in northern Britain. The "evidence suggests that rather than a violent invasion or a single migratory event, the genetic structure of the population changed through sustained contacts between mainland Britain and Europe over several centuries, such as the movement of traders, intermarriage, and small-scale movements of family groups". The authors describe this as

7956-401: The channel as raiders, only later establishing themselves on the island. 122 AD, the Romans fortified the northern border with Hadrian's Wall , which spanned what is now Northern England . In 142 AD, Roman forces pushed north again and began construction of the Antonine Wall , which ran between the Forth–Clyde isthmus, but they retreated back to Hadrian's Wall after only twenty years. Although

8073-455: The depths. These organisms were cosmopolitan in distribution and present at most latitudes. At the end of the second event, melting glaciers caused the sea level to rise and stabilise once more. The rebound of life's diversity with the permanent re-flooding of continental shelves at the onset of the Silurian saw increased biodiversity within the surviving Orders. Recovery was characterized by an unusual number of "Lazarus taxa", disappearing during

8190-412: The details remain unresolved. In particular, some researches interpret the fluctuations in sea level as pre-Hibernian glaciation, but sedimentary evidence of glaciation is lacking until the end of the period. There is evidence of glaciers during the Hirnantian on the land we now know as Africa and South America, which were near the South Pole at the time, facilitating the formation of the ice caps of

8307-419: The diversity of fauna; Ordovician invertebrates displayed a very high degree of provincialism. The widely separated continents of Laurentia and Baltica, then positioned close to the tropics and boasting many shallow seas rich in life, developed distinct trilobite faunas from the trilobite fauna of Gondwana, and Gondwana developed distinct fauna in its tropical and temperature zones. The Tien Shan terrane maintained

8424-775: The early 16th century, and especially after the Acts of Union 1707 , the terms British and Briton could be applied to all inhabitants of the Kingdom of Great Britain , including the English , Scottish , and some Irish , or the subjects of the British Empire generally. The Britons spoke an Insular Celtic language known as Common Brittonic . Brittonic was spoken throughout the island of Britain (in modern terms, England, Wales, and Scotland). According to early medieval historical tradition, such as The Dream of Macsen Wledig ,

8541-671: The early Katian (Boda Event), depositing bioherms and radiating fauna across Europe. The early Katian also witnessed yet another humidification event. Further cooling during the Hirnantian, at the end of the Ordovician, led to the Late Ordovician glaciation . The Ordovician saw the highest sea levels of the Paleozoic, and the low relief of the continents led to many shelf deposits being formed under hundreds of metres of water. The sea level rose more or less continuously throughout

8658-406: The early Ordovician, including the earliest known octocorals , corresponding to an increase in the stability of carbonate and thus a new abundance of calcifying animals. Brachiopods surged in diversity, adapting to almost every type of marine environment. Even after GOBE, there is evidence suggesting that Ordovician brachiopods maintained elevated rates of speciation. Molluscs , which appeared during

8775-479: The extinction and reappearing well into the Silurian, which suggests that the taxa survived in small numbers in refugia . An alternate extinction hypothesis suggested that a ten-second gamma-ray burst could have destroyed the ozone layer and exposed terrestrial and marine surface-dwelling life to deadly ultraviolet radiation and initiated global cooling. Recent work considering the sequence stratigraphy of

8892-597: The fauna that emerged in the Ordovician were the template for the remainder of the Palaeozoic. The fauna was dominated by tiered communities of suspension feeders, mainly with short food chains. The ecological system reached a new grade of complexity far beyond that of the Cambrian fauna, which has persisted until the present day. Though less famous than the Cambrian explosion , the Ordovician radiation (also known as

9009-576: The first rugose corals appeared. The planktonic graptolites remained diverse, with the Diplograptina making their appearance. One of the earliest known armoured agnathan (" ostracoderm ") vertebrates, Arandaspis , dates from the Middle Ordovician. During the Middle Ordovician there was a large increase in the intensity and diversity of bioeroding organisms. This is known as the Ordovician Bioerosion Revolution. It

9126-540: The first millennium BC, reaching Britain towards the end of this period. In 2021, a major archaeogenetics study uncovered a migration into southern Britain during the Bronze Age , over a 500-year period from 1,300 BC to 800 BC. The migrants were "genetically most similar to ancient individuals from France" and had higher levels of Early European Farmers ancestry. From 1000 to 875 BC, their genetic marker swiftly spread through southern Britain, making up around half

9243-676: The first millennium BC. More recently, John Koch and Barry Cunliffe have challenged that with their 'Celtic from the West' theory, which has the Celtic languages developing as a maritime trade language in the Atlantic Bronze Age cultural zone before it spread eastward. Alternatively, Patrick Sims-Williams criticizes both of these hypotheses to propose 'Celtic from the Centre', which suggests Celtic originated in Gaul and spread during

9360-531: The formerly Brittonic ruled territory in Britain, and the language and culture of the native Britons was thereafter gradually replaced in those regions, remaining only in Wales, Cornwall, the Isles of Scilly and Brittany , and for a time in parts of Cumbria, Strathclyde, and eastern Galloway. Cornwall (Kernow, Dumnonia ) had certainly been largely absorbed by England by the 1050s to early 1100s, although it retained

9477-522: The forms", and could be linked to the Latin name Picti (the Picts ), which is usually explained as meaning "painted people". The Old Welsh name for the Picts was Prydyn . Linguist Kim McCone suggests the name became restricted to inhabitants of the far north after Cymry displaced it as the name for the Welsh and Cumbrians . The Welsh prydydd , "maker of forms", was also a term for the highest grade of

9594-560: The largest Brittonic-Pictish kingdom which covered Strathearn , Morayshire and Easter Ross , had fallen by approximately 950 AD to the Gaelic Kingdom of Alba ( Scotland ). Other Pictish kingdoms such as Circinn (in modern Angus and The Mearns ), Fib (modern Fife ), Fidach ( Inverness and Perthshire ), and Ath-Fotla ( Atholl ), had also all fallen by the beginning of the 11th century AD or shortly after. The Brythonic languages in these areas were eventually replaced by

9711-510: The late Silurian and lower Devonian , the combined Baltica and Avalonia collided progressively with Laurentia , beginning with the long extremity of Avalonia, which is now attached to North America. The result of this was the formation of Euramerica . At the completion of this stage, the site of Britain was at 30°S and Nova Scotia at about 45°S. This collision is represented by the Caledonian folding or in North America as an early phase in

9828-486: The later Irish annals suggest it was indeed related to the Common Brittonic language . Their Goidelic (Gaelic) name, Cruithne , is cognate with Pritenī . The following is a list of the major Brittonic tribes, in both the Latin and Brittonic languages, as well as their capitals during the Roman period. The La Tène style , which covers British Celtic art , was late arriving in Britain, but after 300 BC

9945-489: The male side. Wales, Cornwall, Brittany and the Isles of Scilly continued to retain a distinct Brittonic culture, identity and language, which they have maintained to the present day. The Welsh and Breton languages remain widely spoken, and the Cornish language , once close to extinction, has experienced a revival since the 20th century. The vast majority of place names and names of geographical features in Wales, Cornwall,

10062-685: The mid 11th century AD when Cornwall was effectively annexed by the English, with the Isles of Scilly following a few years later, although at times Cornish lords appear to have retained sporadic control into the early part of the 12th century AD. Wales remained free from Anglo-Saxon, Gaelic Scots and Viking control, and was divided among varying Brittonic kingdoms, the foremost being Gwynedd (including Clwyd and Anglesey ), Powys , Deheubarth (originally Ceredigion , Seisyllwg and Dyfed ), Gwent , and Morgannwg ( Glamorgan ). These Brittonic-Welsh kingdoms initially included territories further east than

10179-474: The modern borders of Wales; for example, Powys included parts of modern Merseyside , Cheshire and the Wirral and Gwent held parts of modern Herefordshire , Worcestershire , Somerset and Gloucestershire , but had largely been confined to the borders of modern Wales by the beginning of the 12th century. However, by the early 1100s, the Anglo-Saxons and Gaels had become the dominant cultural force in most of

10296-646: The names of rivers, such as the Thames , Clyde , Severn , Tyne , Wye , Exe , Dee , Tamar , Tweed , Avon , Trent , Tambre , Navia , and Forth . Many place names in England and Scotland are of Brittonic rather than Anglo-Saxon or Gaelic origin, such as London , Manchester , Glasgow , Edinburgh , Carlisle , Caithness , Aberdeen , Dundee , Barrow , Exeter , Lincoln , Dumbarton , Brent , Penge , Colchester , Gloucester , Durham , Dover , Kent , Leatherhead , and York . Schiffels et al. (2016) examined

10413-550: The native Britons south of Hadrian's Wall mostly kept their land, they were subject to the Roman governors , whilst the Brittonic-Pictish Britons north of the wall probably remained fully independent and unconquered. The Roman Empire retained control of "Britannia" until its departure about AD 410, although parts of Britain had already effectively shrugged off Roman rule decades earlier. Thirty years or so after

10530-548: The ophiuroids ("brittle stars") and the first sea stars . Nevertheless, the arthropods remained abundant; all the Late Cambrian orders continued, and were joined by the new group Phacopida . The first evidence of land plants also appeared (see evolutionary history of life ). In the Middle Ordovician, the trilobite-dominated Early Ordovician communities were replaced by generally more mixed ecosystems, in which brachiopods, bryozoans, molluscs, cornulitids , tentaculitids and echinoderms all flourished, tabulate corals diversified and

10647-531: The post-Roman Celtic speakers of Armorica were colonists from Britain, resulting in the Breton language , a language related to Welsh and identical to Cornish in the early period, and is still used today. Thus, the area today is called Brittany (Br. Breizh , Fr. Bretagne , derived from Britannia ). Common Brittonic developed from the Insular branch of the Proto-Celtic language that developed in

10764-411: The pre-Roman Iron Age , until the central Middle Ages ". The earliest known reference to the inhabitants of Britain was made by Pytheas , a Greek geographer who made a voyage of exploration around the British Isles between 330 and 320 BC. Although none of his own writings remain, writers during the following centuries make frequent reference to them. The ancient Greeks called the people of Britain

10881-560: The regions of modern East Anglia , East Midlands , North East England , Argyll , and South East England were the first to fall to the Germanic and Gaelic Scots invasions. The kingdom of Ceint (modern Kent) fell in 456 AD. Linnuis (which stood astride modern Lincolnshire and Nottinghamshire) was subsumed as early as 500 AD and became the English Kingdom of Lindsey. Regni (essentially modern Sussex and eastern Hampshire )

10998-524: The remains of three Iron Age Britons buried ca. 100 BC. A female buried in Linton, Cambridgeshire carried the maternal haplogroup H1e , while two males buried in Hinxton both carried the paternal haplogroup R1b1a2a1a2 , and the maternal haplogroups K1a1b1b and H1ag1 . Their genetic profile was considered typical for Northwest European populations. Though sharing a common Northwestern European origin,

11115-748: The rift which became the Atlantic Ocean . When the term "Avalon" was first coined by Canadian geologist Harold Williams in 1964, he included only Precambrian rocks in eastern Newfoundland. More than a decade later he extended the term to include all exotic rocks from Newfoundland down to Rhode Island. Since the introduction of the term terrane in the 1980s, Avalonia has been referred to as "platform", "composite terrane", "superterrane", "East" and "West Avalonia", and "Avalon sensu lato". "Avalonia" can thus refer exclusively to rocks in Newfoundland (Avalonia sensu stricto ), an assembly of terranes, or

11232-399: The sea level dropped, and the vast shallow intra-continental Ordovician seas withdrew, which eliminated many ecological niches. When they returned, they carried diminished founder populations that lacked many whole families of organisms. They then withdrew again with the next pulse of glaciation, eliminating biological diversity with each change. Species limited to a single epicontinental sea on

11349-426: The sea, and about 49% of genera of fauna disappeared forever; brachiopods and bryozoans were greatly reduced, along with many trilobite , conodont and graptolite families. The most commonly accepted theory is that these events were triggered by the onset of cold conditions in the late Katian, followed by an ice age , in the Hirnantian faunal stage, that ended the long, stable greenhouse conditions typical of

11466-512: The second largest of the five major extinction events in Earth's history in terms of percentage of genera that became extinct. The only larger one was the Permian–Triassic extinction event . The extinctions occurred approximately 447–444 million years ago and mark the boundary between the Ordovician and the following Silurian Period. At that time all complex multicellular organisms lived in

11583-421: The shells of most molluscs , dissolved rapidly on the sea floor after death. Unlike Cambrian times, when calcite production was dominated by microbial and non-biological processes, animals (and macroalgae) became a dominant source of calcareous material in Ordovician deposits. The Early Ordovician climate was very hot, with intense greenhouse conditions and sea surface temperatures comparable to those during

11700-830: The shores of Rodinia together with island arcs now found in the Arabian-Nubian Shield (900–700 Ma) and Tocantins in central Brazil (950–900 Ma) and the basement of Avalonia is most likely of the same age. During the Precambrian-Cambrian transition, Avalonia was located in a cool-water environment and even underwent a glaciation. The Moroccan Anti-Atlas range in West Gondwana was, in contrast, characterised by evaporites , evidence of desiccation , and had thrombolites . Avalonia and Gondwana must therefore have been located far from each other during this period. The two did, however, share

11817-550: The sun's rays from the proposed Ordovician ring system, which also caused the Ordovician meteor event , may have also led to the glaciation. As the southern supercontinent Gondwana drifted over the South Pole, ice caps formed on it, which have been detected in Upper Ordovician rock strata of North Africa and then-adjacent northeastern South America, which were south-polar locations at the time. As glaciers grew,

11934-567: The time of the Roman departure, the Germanic -speaking Anglo-Saxons began a migration to the south-eastern coast of Britain, where they began to establish their own kingdoms, and the Gaelic -speaking Scots migrated from Dál nAraidi (modern Northern Ireland ) to the west coast of Scotland and the Isle of Man. At the same time, Britons established themselves in what is now called Brittany and

12051-446: The trinucleids developed a broad pitted margin around their head shields. Some trilobites such as Asaphus kowalewski evolved long eyestalks to assist in detecting predators whereas other trilobite eyes in contrast disappeared completely. Molecular clock analyses suggest that early arachnids started living on land by the end of the Ordovician. Although solitary corals date back to at least the Cambrian , reef -forming corals appeared in

12168-577: The western Pennines , and as far as modern Leeds in West Yorkshire . Thus the Kingdom of Strathclyde became the last of the Brittonic kingdoms of the 'old north' to fall in the 1090s when it was effectively divided between England and Scotland. The Britons also retained control of Wales and Kernow (encompassing Cornwall , parts of Devon including Dartmoor , and the Isles of Scilly ) until

12285-416: The world's first true vertebrates , continued to evolve, and those with jaws may have first appeared late in the period. About 100 times as many meteorites struck the Earth per year during the Ordovician compared with today in a period known as the Ordovician meteor event . It has been theorized that this increase in impacts may originate from a ring system that formed around Earth at the time. In 2008,

12402-645: Was accompanied by wholesale population changes is still debated. During this time, Britons migrated to mainland Europe and established significant colonies in Brittany (now part of France), the Channel Islands , and Britonia (now part of Galicia , Spain). By the 11th century, Brittonic-speaking populations had split into distinct groups: the Welsh in Wales, the Cornish in Cornwall, the Bretons in Brittany,

12519-537: Was closed off by the Late Ordovician, Iapetus Ocean , and the new Rheic Ocean . For most of the Late Ordovician life continued to flourish, but at and near the end of the period there were mass-extinction events that seriously affected conodonts and planktonic forms like graptolites . The trilobites Agnostida and Ptychopariida completely died out, and the Asaphida were much reduced. Brachiopods , bryozoans and echinoderms were also heavily affected, and

12636-426: Was closely related to Common Brittonic. Following the end of Roman rule in Britain during the 5th century, Anglo-Saxon settlement of eastern and southern Britain began. The culture and language of the Britons fragmented, and much of their territory gradually became Anglo-Saxon , while the north became subject to a similar settlement by Gaelic -speaking tribes from Ireland. The extent to which this cultural change

12753-416: Was conquered by Gaelic Scots in 871 AD. Dumnonia (encompassing Cornwall , Devonshire , and the Isles of Scilly ) was partly conquered during the mid 9th century AD, with most of modern Devonshire being annexed by the Anglo-Saxons, but leaving Cornwall, the Isles of Scilly ( Enesek Syllan ), and for a time part of western Devonshire (including Dartmoor ), still in the hands of the Britons, where they became

12870-416: Was conquered by the Anglo-Saxons in 627 AD. Pengwern , which covered Staffordshire , Shropshire , Herefordshire , and Worcestershire , was largely destroyed in 656 AD, with only its westernmost parts in modern Wales remaining under the control of the Britons, and it is likely that Cynwidion, which had stretched from modern Bedfordshire to Northamptonshire, fell in the same general period as Pengwern, though

12987-606: Was distributed widely during peak sea levels in the Sandbian. Some new cystoids and crinoids appeared. It was long thought that the first true vertebrates (fish — Ostracoderms ) appeared in the Ordovician, but recent discoveries in China reveal that they probably originated in the Early Cambrian . The first gnathostome (jawed fish) may have appeared in the Late Ordovician epoch. Chitinozoans, which first appeared late in

13104-452: Was likely fully conquered by 510 AD. Ynys Weith (Isle of Wight) fell in 530 AD, Caer Colun (essentially modern Essex) by 540 AD. The Gaels arrived on the northwest coast of Britain from Ireland, dispossessed the native Britons, and founded Dal Riata which encompassed modern Argyll , Skye , and Iona between 500 and 560 AD. Deifr (Deira) which encompassed modern-day Teesside, Wearside, Tyneside, Humberside, Lindisfarne ( Medcaut ), and

13221-492: Was limited to the Iapetus margin of Laurentia; elsewhere, the pattern was of rifting in back-arc basins followed by remerger. This reflected episodic switching from extension to compression. The initiation of new subduction reflected a global reorganization of tectonic plates centered on the amalgamation of Gondwana. The Taconic orogeny , a major mountain-building episode, was well under way in Cambrian times. This continued into

13338-430: Was made up of many tribes and kingdoms, associated with various hillforts . The Britons followed an Ancient Celtic religion overseen by druids . Some of the southern tribes had strong links with mainland Europe, especially Gaul and Belgica , and minted their own coins . The Roman Empire conquered most of Britain in the 1st century AD, creating the province of Britannia . The Romans invaded northern Britain , but

13455-544: Was marked by the Ordovician–Silurian extinction events . Invertebrates, namely molluscs and arthropods , dominated the oceans, with members of the latter group probably starting their establishment on land during this time, becoming fully established by the Devonian . The first land plants are known from this period. The Great Ordovician Biodiversification Event considerably increased the diversity of life. Fish ,

13572-562: Was originally compiled by the orders of King Alfred the Great in approximately 890, starts with this sentence: "The island Britain is 800 miles long and 200 miles broad. And there are in the island five nations; English, Welsh (or British), Scottish, Pictish, and Latin. The first inhabitants were the Britons, who came from Armenia, and first peopled Britain southward" ("Armenia" is possibly a mistaken transcription of Armorica , an area in northwestern Gaul including modern Brittany ). In 43 AD,

13689-467: Was used by Celtic Britons during war and ceremony. There are competing hypotheses for when Celtic peoples, and the Celtic languages, first arrived in Britain, none of which have gained consensus. The traditional view during most of the twentieth century was that Celtic culture grew out of the central European Hallstatt culture , from which the Celts and their languages reached Britain in the second half of

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