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112-837: The Cache Creek Terrane consists of Carboniferous to Lower Jurassic volcanic rocks , carbonate rocks , coarse clastic rocks and small amounts of ultramafic rock , chert and argillite . Three geological formations comprise the Cache Creek Terrane: the Sitlika Assemblage, the Tezzeron succession and the Cache Creek Complex. This terrane is mentioned in the video Where terranes collide (done in conjunction with Canada's geologic survey). Research Papers Books, Periodicals 59°N 132°W  /  59°N 132°W  / 59; -132 This article about

224-403: A detritivore , like most extant millipedes. This means feeding on either dead and decaying plant matter or animal remains when available. The short, closely packed legs, as well as evidence from the morphology of the ichnofossil trackways, both suggest that Arthropleura was a very slow moving animal, and the lack of venomous forcipules or other predatory adaptions to the limbs basically precludes

336-431: A 100 kyr Milankovitch cycle , and so each cyclothem represents a cycle of sea level fall and rise over a 100 kyr period. Coal forms when organic matter builds up in waterlogged, anoxic swamps, known as peat mires, and is then buried, compressing the peat into coal. The majority of Earth's coal deposits were formed during the late Carboniferous and early Permian. The plants from which they formed contributed to changes in

448-535: A car bumper. The cephalic limbs showed two pairs of external maxillae, and an internal set of mandibles. Phylogenetic analysis found Arthropleura just outside of Diplopoda (stem-group Diplopoda), while Microdecemplex was found as a crown-group millipede rather than an arthropleuridean. Multiple partial specimens and trackways suggest that Arthropleura could exceed 2 metres (6 ft 7 in) long. Tracks from Arthropleura up to 50 centimetres (20 in) wide have been found at Joggins, Nova Scotia . In 2021

560-481: A defined GSSP. The fusulinid Aljutovella aljutovica can be used to define the base of the Moscovian across the northern and eastern margins of Pangea, however, it is restricted in geographic area, which means it cannot be used for global correlations. The first appearance of the conodonts Declinognathodus donetzianus or Idiognathoides postsulcatus have been proposed as a boundary marking species and potential sites in

672-400: A fossil, probably a shed exoskeleton ( exuviae ) of an Arthropleura (indeterminate species, as due to its exposure of only the underside of the carapace, ornamentation cannot be observed), was reported with an estimated width of 55 centimetres (22 in), length of 1.9 metres (6 ft 3 in) to 2.63 metres (8 ft 8 in) and body mass of 50 kg (110 lb). It is one of

784-546: A location in the Interior of British Columbia , Canada is a stub . You can help Misplaced Pages by expanding it . This article about a specific Canadian geological feature is a stub . You can help Misplaced Pages by expanding it . Carboniferous The Carboniferous ( / ˌ k ɑːr b ə ˈ n ɪ f ər ə s / KAR -bə- NIF -ər-əs ) is a geologic period and system of the Paleozoic era that spans 60 million years from

896-432: A lower walking leg and an upper gill branch, like the biramous limbs of trilobites. Palaeontologist Leif Størmer remarked on this study in 1944, writing that after careful study of the photographs, the supposed two branches of the limb are always found close together, close enough that even their joints consistently line up. Because of this, he interpreted the limbs as uniramous, having only a single branch. Waterlot referred

1008-494: A nearly complete juvenile specimen described by Dr. W. T. Calman as Arthropleura moyseyi to Arthropleura armata , and agreed that this specimen showed the mostly unknown head segment of the animal. A curved structure found along the edge of the head resembled the mandibles of some myraipods, and so it was seen by Waterlot as a cephalic feeding appendage, and that this meant Arthropleura was carnivorous , feeding on small soft-bodied prey. Waterlot also believed that Arthropleura

1120-476: A number of specimens (such as in the Maybach specimen) as oval-shaped plates with rough granulose ornamentation, and would have provided an attachment point for trunk musculature. Arthropleura had two pairs of maxillae appendages beneath the head, each composed of 3 segments (podomeres). Their morphology are similar to those of a centipede: the outermost pair (second maxillae) being relatively long and pointed, while

1232-433: A pair of antennae with at least seven antennal articles at the front of its head. The trunk anatomy of Arthropleura is characterized by a series of well-developed 28-32 tergites (dorsal exoskeleton ) having three lobes like a trilobite , the dorsal surface of which is typically covered by many tubercles or spines. Juvenile specimens have fewer numbers of tergites at 20-24, suggesting hemianamorphic development , with

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1344-604: A predatory lifestyle. The giant size of Arthropleura has been frequently attributed to higher oxygen levels during the Carboniferous . However, this does not align with the fossil record or modern understanding of arthropod size range. Arthropleura reaches giant sizes before the rise in oxygen concentration during the Carboniferous, with the largest known body fossil found in an interval where oxygen levels were only about 23% higher than modern day. More likely, Arthropleura

1456-401: A semi-aquatic, amphibious lifestyle, capable of entering and exiting shallow bodies of water. It has been suggested that due to their large size, moulting (a stressful period even for smaller arthropods) probably occurred underwater, allowing its weight to be supported while its new exoskeleton hardened. Wilson favoured a more terrestrial habit for Arthropleura , with no obvious mechanism for

1568-431: A shallow, tropical seaway which stretched from Southern California to Alaska. The boundary is within a cyclothem sequence of transgressive limestones and fine sandstones , and regressive mudstones and brecciated limestones. The Moscovian Stage is named after shallow marine limestones and colourful clays found around Moscow, Russia. It was first introduced by Sergei Nikitin in 1890. The Moscovian currently lacks

1680-451: A single sedimentary cycle, with an erosional surface at its base. Whilst individual cyclothems are often only metres to a few tens of metres thick, cyclothem sequences can be many hundreds to thousands of metres thick and contain tens to hundreds of individual cyclothems. Cyclothems were deposited along continental shelves where the very gentle gradient of the shelves meant even small changes in sea level led to large advances or retreats of

1792-453: A small specimen of Arthropleura armata showing the underside, with a series of 7 pairs of limbs articulated with various other plates, including the sternites . Kliver that Arthropleura could not be an insect , arachnid , or myriapod , but instead that it was a non-decapod crustacean, comparing the appendages to those of branchiopods . Following authors tended to view Arthropleura in connection to isopods , some believing it represented

1904-538: A small, tuberculate, trapezoidal telson . The different species of Arthropleura are primarily differentiated by the dorsal ornamentation of their tergites. There is a keel across the middle of the tergites running laterally in all species, and typically, there is a line of large tubercules running behind it. The only exception is A. cristata from the Mazon Creek of the United States, where tuberculate ornamentation

2016-419: A taphonomic artifact. The most complete known adult specimen of Arthropleura (the Maybach specimen) was described by Paul Guthörl in 1935, discovered in the roof of a German coal mine and carefully extracted, measuring 90 centimetres (35 in) long. Arthropleura as a myriapod or relative of myriapods (particularly diplopods ) becaming the prevailing view among scientists in the following decades, and

2128-624: A tropical wetland environment. Extensive coal deposits developed within the cyclothem sequences that dominated the Pennsylvanian sedimentary basins associated with the growing orogenic belt. Subduction of the Panthalassic oceanic plate along its western margin resulted in the Antler orogeny in the Late Devonian to Early Mississippian. Further north along the margin, slab roll-back , beginning in

2240-423: A variety of methods for reconstructing past atmospheric oxygen levels, including the charcoal record, halite gas inclusions, burial rates of organic carbon and pyrite , carbon isotopes of organic material, isotope mass balance and forward modelling. Depending on the preservation of source material, some techniques represent moments in time (e.g. halite gas inclusions), whilst others have a wider time range (e.g.

2352-425: A very primitive Eumalacostracan crusteacean. Palaeontologists Lewis Moysey and Henry Woodward were the first to associate Arthropleura with Myriapoda in 1911. Gérard Waterlot published a landmark study in 1934, establishing the order Arthropleurida , placing the group as sister to order Trilobita, within the defunct crustacean subclass Archaeocrustacea. He believed the limbs to be composed of two branches ,

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2464-725: A warmer climate. This rapid rise in CO 2 may have been due to a peak in pyroclastic volcanism and/or a reduction in burial of terrestrial organic matter. The LPIA peaked across the Carboniferous-Permian boundary. Widespread glacial deposits are found across South America, western and central Africa, Antarctica, Australia, Tasmania, the Arabian Peninsula, India, and the Cimmerian blocks, indicating trans-continental ice sheets across southern Gondwana that reached to sea-level. In response to

2576-464: Is absent. Because complete specimens are rare, species are sometimes poorly delineated, and could possibly represent different growth stages of the a smaller number of species, leading paleontologists who work with Arthropleura to often only give a genus-level identification to the fossils. The Montceau-les-Mines species (known from only juvenile specimens) has a band of 4 large tubercules on the paratergal lobe, which rise up into tall spines. This pattern

2688-520: Is divided into small triangular lobes - the creases between them probably functioned as internal apodemes , muscule attachment for the limbs. The B-plate, which may be homologous with the coxa or basal leg segment in other arthropods, is continuous with the rosette plate. The placement of all these plates infront of the limb also suggests the legs would thrust backward and downward during movement, before returning to their standard position, with little capacity for movement forward. The body terminated with

2800-426: Is extremely similar to A. moyseyi , which suggests that A. moyseyi is also a juvenile, possibly of A. mammata . Because the ornamentation may change over time, it is not viewed as a reliable way to determine species. At Montceau-les-Mines, large specimens are absent, and the largest trackways were left by animals less than 50 centimetres (20 in) in length, so this species may have been genuinely much smaller than

2912-508: Is located in Bed 83 of the sequence of dark grey limestones and shales at the Pengchong section, Guangxi , southern China. It is defined by the first appearance of the fusulinid Eoparastaffella simplex in the evolutionary lineage Eoparastaffella ovalis – Eoparastaffella simplex and was ratified in 2009. The Serpukhovian Stage was proposed in 1890 by Russian stratigrapher Sergei Nikitin . It

3024-517: Is named after the Russian village of Gzhel , near Ramenskoye , not far from Moscow. The name and type locality were defined by Sergei Nikitin in 1890. The Gzhelian currently lacks a defined GSSP. The first appearance of the fusulinid Rauserites rossicus and Rauserites stuckenbergi can be used in the Boreal Sea and Paleo-Tethyan regions but not eastern Pangea or Panthalassa margins. Potential sites in

3136-438: Is named after the city of Serpukhov , near Moscow. currently lacks a defined GSSP. The Visean-Serpukhovian boundary coincides with a major period of glaciation. The resulting sea level fall and climatic changes led to the loss of connections between marine basins and endemism of marine fauna across the Russian margin. This means changes in biota are environmental rather than evolutionary making wider correlation difficult. Work

3248-626: Is that a delay between the development of trees with the wood fibre lignin and the subsequent evolution of lignin-degrading fungi gave a period of time where vast amounts of lignin-based organic material could accumulate. Genetic analysis of basidiomycete fungi, which have enzymes capable of breaking down lignin, supports this theory by suggesting this fungi evolved in the Permian. However, significant Mesozoic and Cenozoic coal deposits formed after lignin-digesting fungi had become well established, and fungal degradation of lignin may have already evolved by

3360-643: Is underway in the Urals and Nashui, Guizhou Province, southwestern China for a suitable site for the GSSP with the proposed definition for the base of the Serpukhovian as the first appearance of conodont Lochriea ziegleri . The Pennsylvanian was proposed by J.J.Stevenson in 1888, named after the widespread coal-rich strata found across the state of Pennsylvania. The closure of the Rheic Ocean and formation of Pangea during

3472-688: The Gulf of Mexico in the west to Turkey in the east. The orogeny was caused by a series of continental collisions between Laurussia, Gondwana and the Armorican Terrane Assemblage (much of modern-day Central and Western Europe including Iberia ) as the Rheic Ocean closed and Pangea formed. This mountain building process began in the Middle Devonian and continued into the early Permian. The Armorican terranes rifted away from Gondwana during

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3584-721: The International Commission on Stratigraphy (ICS) stage, but the Viséan is longer, extending into the lower Serpukhovian . North American geologists recognised a similar stratigraphy but divided it into two systems rather than one. These are the lower carbonate-rich sequence of the Mississippian System and the upper siliciclastic and coal-rich sequence of the Pennsylvanian . The United States Geological Survey officially recognised these two systems in 1953. In Russia, in

3696-661: The Kuznetsk Basin . The northwest to eastern margins of Siberia were passive margins along the Mongol-Okhotsk Ocean on the far side of which lay Amuria. From the mid Carboniferous, subduction zones with associated magmatic arcs developed along both margins of the ocean. The southwestern margin of Siberia was the site of a long lasting and complex accretionary orogen. The Devonian to early Carboniferous Siberian and South Chinese Altai accretionary complexes developed above an east-dipping subduction zone, whilst further south,

3808-668: The Latin carbō (" coal ") and ferō ("bear, carry"), and refers to the many coal beds formed globally during that time. The first of the modern "system" names, it was coined by geologists William Conybeare and William Phillips in 1822, based on a study of the British rock succession. Carboniferous is the period during which both terrestrial animal and land plant life was well established. Stegocephalia (four-limbed vertebrates including true tetrapods ), whose forerunners ( tetrapodomorphs ) had evolved from lobe-finned fish during

3920-566: The Magnitogorsk island arc , which lay between Kazakhstania and Laurussia in the Ural Ocean , collided with the passive margin of northeastern Laurussia ( Baltica craton ). The suture zone between the former island arc complex and the continental margin formed the Main Uralian Fault , a major structure that runs for more than 2,000 km along the orogen. Accretion of the island arc

4032-483: The Montceau-les-Mines Lagerstätte of France were studied and described with the aid of Micro-CT scanning, revealing the head region in two nearly complete juvenile Arthropleura fossils. They showed that the head identified by past authors was indeed the head, with the collum a thin segment behind it. Waterlot's cephalic limbs are now identified as paired ventral scleites, protecting the head like

4144-653: The Old Red Sandstone , Carboniferous Limestone , Millstone Grit and the Coal Measures . These four units were placed into a formalised Carboniferous unit by William Conybeare and William Phillips in 1822 and then into the Carboniferous System by Phillips in 1835. The Old Red Sandstone was later considered Devonian in age. The similarity in successions between the British Isles and Western Europe led to

4256-691: The 1840s British and Russian geologists divided the Carboniferous into the Lower, Middle and Upper series based on Russian sequences. In the 1890s these became the Dinantian, Moscovian and Uralian stages. The Serpukivian was proposed as part of the Lower Carboniferous, and the Upper Carboniferous was divided into the Moscovian and Gzhelian . The Bashkirian was added in 1934. In 1975, the ICS formally ratified

4368-484: The 21st century. What had previously been identified as the head was reinterpreted as the collum, the first segment behind the head, with the true head hidden beneath it. The Devonian millipede Microdecemplex was described in 1999, and was believed to belong to the subclass Arthropleuridea . Thse tiny fossils were much more complete, and so its head anatomy was taken as an insight into the head of Arthropleura . Finally, in 2024, exceptionally preserved fossils from

4480-520: The Bashkirian, the late Moscovian and the latest Kasimovian to mid-Gzhelian are inferred from the disappearance of glacial sediments, the appearance of deglaciation deposits and rises in sea levels. In the early Kasimovian there was short-lived (<1 million years) intense period of glaciation, with atmospheric CO 2 concentration levels dropping as low as 180 ppm. This ended suddenly as a rapid increase in CO 2 concentrations to c. 600 ppm resulted in

4592-726: The Carboniferous Earth's atmosphere, and the coal fueled the Industrial Revolution . During the Pennsylvanian, vast amounts of organic debris accumulated in the peat mires that formed across the low-lying, humid equatorial wetlands of the foreland basins of the Central Pangean Mountains in Laurussia, and around the margins of the North and South China cratons. During glacial periods, low sea levels exposed large areas of

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4704-641: The Carboniferous System, with the Mississippian and Pennsylvanian subsystems from the North American timescale, the Tournaisian and Visean stages from the Western European and the Serpukhovian, Bashkirian, Moscovian, Kasimovian and Gzhelian from the Russian. With the formal ratification of the Carboniferous System, the Dinantian, Silesian, Namurian, Westphalian and Stephanian became redundant terms, although

4816-591: The Carboniferous, the Tarim craton lay along the northwestern edge of North China. Subduction along the Kazakhstanian margin of the Turkestan Ocean resulted in collision between northern Tarim and Kazakhstania during the mid Carboniferous as the ocean closed. The South Tian Shan fold and thrust belt , which extends over 2,000 km from Uzbekistan to northwest China, is the remains of this accretionary complex and forms

4928-725: The Early Mississippian, led to the rifting of the Yukon-Tanana terrane and the opening of the Slide Mountain Ocean . Along the northern margin of Laurussia, orogenic collapse of the Late Devonian to Early Mississippian Innuitian orogeny led to the development of the Sverdrup Basin . Much of Gondwana lay in the southern polar region during the Carboniferous. As the plate moved, the South Pole drifted from southern Africa in

5040-509: The Early to Middle Mississippian, carbonate production occurred to depth across the gently dipping continental slopes of Laurussia and North and South China ( carbonate ramp architecture) and evaporites formed around the coastal regions of Laurussia, Kazakhstania, and northern Gondwana. From the late Visean, the cooling climate restricted carbonate production to depths of less than c. 10 m forming carbonate shelves with flat-tops and steep sides. By

5152-530: The K-plate was actually sac-shaped with a hollow interior. The outer surface of the K-plate was covered in pitted setae, and the interior of the K-plate was reticulate, possibly serving as a respiratory organ . In this case, movement of the limbs would have helped pump hemolymph in and out of the respiratory apparatus. The spiracle opening to the lungs has never been identified, and the respiratory abilities of Arthropleura are still mostly unknown. The rosette plate

5264-485: The Kasimovian covers a period of globally low sea level, which has resulted in disconformities within many sequences of this age. This has created difficulties in finding suitable marine fauna that can used to correlate boundaries worldwide. The Kasimovian currently lacks a defined GSSP; potential sites in the southern Urals, southwest USA and Nashui, Guizhou Province, southwestern China are being considered. The Gzhelian

5376-476: The Late Ordovician . As they drifted northwards the Rheic Ocean closed in front of them, and they began to collide with southeastern Laurussia in the Middle Devonian. The resulting Variscan orogeny involved a complex series of oblique collisions with associated metamorphism , igneous activity, and large-scale deformation between these terranes and Laurussia, which continued into the Carboniferous. During

5488-635: The Late Pennsylvanian, deformation along the Alleghanian orogen became northwesterly-directed compression . The Uralian orogeny is a north–south trending fold and thrust belt that forms the western edge of the Central Asian Orogenic Belt . The Uralian orogeny began in the Late Devonian and continued, with some hiatuses, into the Jurassic . From the Late Devonian to early Carboniferous,

5600-463: The Moscovian, the waxing and waning of the ice sheets led to cyclothem deposition with mixed carbonate-siliciclastic sequences deposited on continental platforms and shelves. Arthropleura Arthropleura (Greek for 'jointed ribs') is a genus of massive myriapod that lived in what is now Europe and North America around 345 to 290 million years ago , from the Viséan stage of

5712-615: The Paleo-Tethys to the southwest and Panthalassa to the northeast. Cyclothem sediments with coal and evaporites were deposited across the passive margins that surrounded both continents. The Carboniferous climate was dominated by the Late Paleozoic Ice Age (LPIA), the most extensive and longest icehouse period of the Phanerozoic, which lasted from the Late Devonian to the Permian (365 Ma-253 Ma). Temperatures began to drop during

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5824-459: The Pennsylvanian, cyclothems were deposited in shallow, epicontinental seas across the tropical regions of Laurussia (present day western and central US, Europe, Russia and central Asia) and the North and South China cratons . The rapid sea levels fluctuations they represent correlate with the glacial cycles of the Late Paleozoic Ice Age. The advance and retreat of ice sheets across Gondwana followed

5936-402: The Pennsylvanian, together with widespread glaciation across Gondwana led to major climate and sea level changes, which restricted marine fauna to particular geographic areas thereby reducing widespread biostratigraphic correlations. Extensive volcanic events associated with the assembling of Pangea means more radiometric dating is possible relative to the Mississippian. The Bashkirian Stage

6048-475: The Period. This was not a steady rise, but included peaks and troughs reflecting the dynamic climate conditions of the time. How the atmospheric oxygen concentrations influenced the large body size of arthropods and other fauna and flora during the Carboniferous is also a subject of ongoing debate. The changing climate was reflected in regional-scale changes in sedimentation patterns. In the relatively warm waters of

6160-480: The Permian. The Kazakhstanian microcontinent is composed of a series of Devonian and older accretionary complexes. It was strongly deformed during the Carboniferous as its western margin collided with Laurussia during the Uralian orogen and its northeastern margin collided with Siberia. Continuing strike-slip motion between Laurussia and Siberia led the formerly elongate microcontinent to bend into an orocline . During

6272-542: The Urals and Nashui, Guizhou Province, southwestern China are being considered. The Kasimovian is the first stage in the Upper Pennsylvanian. It is named after the Russian city of Kasimov , and was originally included as part of Nikitin's 1890 definition of the Moscovian. It was first recognised as a distinct unit by A.P. Ivanov in 1926, who named it the " Tiguliferina " Horizon after a type of brachiopod . The boundary of

6384-490: The Urals and Nashui, Guizhou Province, southwestern China for the GSSP are being considered. The GSSP for the base of the Permian is located in the Aidaralash River valley near Aqtöbe , Kazakhstan and was ratified in 1996. The beginning of the stage is defined by the first appearance of the conodont Streptognathodus postfusus . A cyclothem is a succession of non-marine and marine sedimentary rocks , deposited during

6496-463: The Visean of c. 15.3%, although with large uncertainties; and, pyrite records suggest levels of c. 15% early in the Carboniferous, to over 25% during the Pennsylvanian, before dropping back below 20% towards the end. However, whilst exact numbers vary, all models show an overall increase in atmospheric oxygen levels from a low of between 15-20% at the beginning of the Carboniferous to highs of 25-30% during

6608-511: The Zharma-Saur arc formed along the northeastern margin of Kazakhstania. By the late Carboniferous, all these complexes had accreted to the Siberian craton as shown by the intrusion of post-orogenic granites across the region. As Kazakhstania had already accreted to Laurussia, Siberia was effectively part of Pangea by 310 Ma, although major strike-slip movements continued between it and Laurussia into

6720-411: The animal from rapidly drying out. The diet of Arthropleura has also been heavily debated. Waterlot suggested it was a carnivore , but the holotype of " A. moyseyi " was suggested to preserve the original gut contents, a mix of woody plant material, suggesting it was an herbivore . The interpretation of these fossils as gut contents is no longer supported. Currently, Arthropleura is believed to be

6832-490: The animal to breath underwater. She suggested that during moulting, Arthropleura could have behaved like modern Scolopendra centipedes, moving in a worm-like fashion without use of their softened legs until they were hardened. She suggested the moulting could have been understaken inside constructed burrows, although remained open to Rolfe (1985)'s theory that moulting was done inside hollow lycopod tree trunks, aided by their naturally high humidity which could have prevented

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6944-647: The average temperature in the tropics c. 24 °C (75 °F) and in polar regions c. -23 °C (-10 °F), whilst during the Early Tournaisian Warm Interval (358-353 Ma) the GAT was c. 22 °C (72 °F), the tropics c. 30 °C (86 °F) and polar regions c. 1.5 °C (35 °F). Overall, for the Ice Age the GAT was c. 17 °C (62 °F), with tropical temperatures c. 26 °C and polar temperatures c. -9.0 °C (16 °F). There are

7056-516: The base of the Carboniferous System, Mississippian Subsystem and Tournaisian Stage is located at the La Serre section in Montagne Noire , southern France. It is defined by the first appearance of the conodont Siphonodella sulcata within the evolutionary lineage from Siphonodella praesulcata to Siphonodella sulcata . This was ratified by the ICS in 1990. However, in 2006 further study revealed

7168-433: The beginning of the Period to highs of 25-30%. The development of a Carboniferous chronostratigraphic timescale began in the late 18th century. The term "Carboniferous" was first used as an adjective by Irish geologist Richard Kirwan in 1799 and later used in a heading entitled "Coal-measures or Carboniferous Strata" by John Farey Sr. in 1811. Four units were originally ascribed to the Carboniferous, in ascending order,

7280-410: The charcoal record and pyrite). Results from these different methods for the Carboniferous vary. For example: the increasing occurrence of charcoal produced by wildfires from the Late Devonian into the Carboniferous indicates increasing oxygen levels, with calculations showing oxygen levels above 21% for most of the Carboniferous; halite gas inclusions from sediments dated 337-335 Ma give estimates for

7392-562: The city of Visé , Liège Province , Belgium. In 1967, the base of the Visean was officially defined as the first black limestone in the Leffe facies at the Bastion Section in the Dinant Basin . These changes are now thought to be ecologically driven rather than caused by evolutionary change, and so this has not been used as the location for the GSSP. Instead, the GSSP for the base of the Visean

7504-411: The complexity of the geology. The ICS subdivisions from youngest to oldest are as follows: The Mississippian was proposed by Alexander Winchell in 1870 named after the extensive exposure of lower Carboniferous limestone in the upper Mississippi River valley. During the Mississippian, there was a marine connection between the Paleo-Tethys and Panthalassa through the Rheic Ocean resulting in

7616-437: The continental shelves. Major river channels, up to several kilometres wide, stretched across these shelves feeding a network of smaller channels, lakes and peat mires. These wetlands were then buried by sediment as sea levels rose during interglacials . Continued crustal subsidence of the foreland basins and continental margins allowed this accumulation and burial of peat deposits to continue over millions of years resulting in

7728-407: The development of a common European timescale with the Carboniferous System divided into the lower Dinantian , dominated by carbonate deposition and the upper Silesian with mainly siliciclastic deposition. The Dinantian was divided into the Tournaisian and Viséan stages. The Silesian was divided into the Namurian , Westphalian and Stephanian stages. The Tournaisian is the same length as

7840-662: The dominance of such coal forests, and direct geological and paleobotanical evidence suggests its primary habitat was far more open. Arthropleura preferred open environments, particularly sparsely wooded and near to water, such as coastlines and floodplains . Arthropleura is also found in association with tetrapod trackways suggesting they lived in the same environments. In addition to large trackways, enormous burrows have been attributed to Arthropleura and arthropleurids generally, suggested to be made during periods of aestivation similar to hibernation. Arthropleura remains (body fossils and trackways) are also closely associated with

7952-475: The early Carboniferous Kanimblan Orogeny . Continental arc magmatism continued into the late Carboniferous and extended round to connect with the developing proto-Andean subduction zone along the western South American margin of Gondwana. Shallow seas covered much of the Siberian craton in the early Carboniferous. These retreated as sea levels fell in the Pennsylvanian and as the continent drifted north into more temperate zones extensive coal deposits formed in

8064-580: The early Carboniferous in North China. However, bauxite deposits immediately above the regional mid Carboniferous unconformity indicate warm tropical conditions and are overlain by cyclothems including extensive coals. South China and Annamia (Southeast Asia) rifted from Gondwana during the Devonian. During the Carboniferous, they were separated from each other and North China by the Paleoasian Ocean with

8176-563: The early Carboniferous to eastern Antarctica by the end of the period. Glacial deposits are widespread across Gondwana and indicate multiple ice centres and long-distance movement of ice. The northern to northeastern margin of Gondwana (northeast Africa, Arabia, India and northeastern West Australia) was a passive margin along the southern edge of the Paleo-Tethys with cyclothem deposition including, during more temperate intervals, coal swamps in Western Australia. The Mexican terranes along

8288-647: The end of the Devonian Period 358.9 Ma (million years ago) to the beginning of the Permian Period, 298.9 Ma. It is the fifth and penultimate period of the Paleozoic era and the fifth period of the Phanerozoic eon . In North America , the Carboniferous is often treated as two separate geological periods, the earlier Mississippian and the later Pennsylvanian . The name Carboniferous means " coal -bearing", from

8400-523: The end of the Carboniferous, extension and rifting across the northern margin of Gondwana led to the breaking away of the Cimmerian Terrane during the early Permian and the opening of the Neo-Tethys Ocean . Along the southeastern and southern margin of Gondwana (eastern Australia and Antarctica), northward subduction of Panthalassa continued. Changes in the relative motion of the plates resulted in

8512-451: The end of the Devonian, even if the specific enzymes used by basidiomycetes had not. The second theory is that the geographical setting and climate of the Carboniferous were unique in Earth's history: the co-occurrence of the position of the continents across the humid equatorial zone, high biological productivity, and the low-lying, water-logged and slowly subsiding sedimentary basins that allowed

8624-475: The formation of thick and widespread coal formations. During the warm interglacials, smaller coal swamps with plants adapted to the temperate conditions formed on the Siberian craton and the western Australian region of Gondwana. There is ongoing debate as to why this peak in the formation of Earth's coal deposits occurred during the Carboniferous. The first theory, known as the delayed fungal evolution hypothesis,

8736-470: The giant species elsewhere in Europe. Most fossils of Arthropleura are believed to represent exuviae ( moulted shells) instead of carcasses . Arthropleura has typically been reconstructed living in coal swamps, based on the co-occurence of its fossils with dense plant remains and coal veins. However, this view is no longer strictly supported. Many fossils of Arthropleura are found either before or after

8848-408: The inner pair (first maxillae) were short and plate-like. The paired mandibles were small, composed of three segments, and fully internalized into the head, similar to centipedes rather than millipedes. The segmentation of antennae and mandibles identify it as a millipede, but the presence of a pair of legs underneath its collum, which is absent in present day species, reveals it as the sister group of

8960-481: The largest arthropods ever known, as large as the eurypterid Jaekelopterus rhenaniae , whose length is estimated at 2.33–2.59 metres (7 ft 8 in – 8 ft 6 in). The 2024 study reported the complete head and trunk of a juvenile specimen of Arthropleura sp. (MNHN.F.SOT002123) from Kasimovian (~305 Ma) Montceau-les-Mines lagerstätte , which revealed multiple previously unknown features. Arthropleura had large, flattened ventral sclerites and

9072-456: The late Carboniferous. Land arthropods such as arachnids (e.g. trigonotarbids and Pulmonoscorpius ), myriapods (e.g. Arthropleura ) and especially insects (particularly flying insects ) also underwent a major evolutionary radiation during the late Carboniferous. Vast swaths of forests and swamps covered the land, which eventually became the coal beds characteristic of the Carboniferous stratigraphy evident today. The later half of

9184-496: The late Devonian with a short-lived glaciation in the late Famennian through Devonian–Carboniferous boundary, before the Early Tournaisian Warm Interval. Following this, a reduction in atmospheric CO 2 levels, caused by the increased burial of organic matter and widespread ocean anoxia led to climate cooling and glaciation across the south polar region. During the Visean Warm Interval glaciers nearly vanished retreating to

9296-526: The latter three are still in common use in Western Europe. Stages can be defined globally or regionally. For global stratigraphic correlation, the ICS ratify global stages based on a Global Boundary Stratotype Section and Point (GSSP) from a single formation (a stratotype ) identifying the lower boundary of the stage. Only the boundaries of the Carboniferous System and three of the stage bases are defined by global stratotype sections and points because of

9408-427: The leg which probably allowed for stronger muscle attachment as an apodeme , and the ventral surface bore paired endites on each segment (actually macro-setae, set in sockets and presumably mobile). The anterior surface of the leg was smooth, while the posterior surface was tuberculate, with many pores that housed sensory setae . Around each walking leg pair, there were three pairs of ventral plates located alongside

9520-474: The limbs became quite well understood. Further species of Arthropleura have been described over the decades, mostly from central Europe and the UK , and even from the central United States with Arthropleura cristata. North American remains are also known from widespread walking traces, as well as fossil remains from Nova Scotia , Ohio , and Pennsylvania . The head segment, however, remained enigmatic even into

9632-597: The lower Carboniferous Period to the Sakmarian stage of the lower Permian Period. It is related to millipedes , and was capable of reaching at least 2 metres (6 ft 7 in) in length, possibly up to over 2.5 metres (8 ft 2 in), making it the largest known land arthropod of all time. Arthropleura is known from body fossils as well as trace fossils, particularly giant trackways up to 50 centimetres (20 in) wide, and potentially also large burrows. It lived in open, sparsely wooded environments near water, and

9744-432: The majority of a cyclothem sequence occurred during falling sea levels, when rates of erosion were high, meaning they were often periods of non-deposition. Erosion during sea level falls could also result in the full or partial removal of previous cyclothem sequences. Individual cyclothems are generally less than 10 m thick because the speed at which sea level rose gave only limited time for sediments to accumulate. During

9856-511: The median sternite , namely K-plates, B-plates, and rosette plates, and either the B-plates or K-plates were thought to be respiratory organs . This has however also been questioned, with Rolfe and Ingham (1967) considering all of these plates to be simply sclerotized ventral integument responsible for reinforcing and buttressing the limb bases to enable locomotion for such a large animal. Wilson (1999) disagreed with this interpretation, stating that

9968-656: The mid Carboniferous, the South American sector of Gondwana collided obliquely with Laurussia's southern margin resulting in the Ouachita orogeny. The major strike-slip faulting that occurred between Laurussia and Gondwana extended eastwards into the Appalachian Mountains where early deformation in the Alleghanian orogeny was predominantly strike-slip. As the West African sector of Gondwana collided with Laurussia during

10080-401: The millipede crown group . Unlike any living myriapods, they had stalked compound eyes, which despite also being known from the extinct stem-myriapod group Euthycarcinoidea , appears to be a derived trait evolved independently from the euthycarcinoids. Each body segment bore two pairs of walking legs, which themselves are composed of 9 or 10 segments (podomeres). A crease ran down each side of

10192-451: The near worldwide distribution of marine faunas and so allowing widespread correlations using marine biostratigraphy . However, there are few Mississippian volcanic rocks , and so obtaining radiometric dates is difficult. The Tournaisian Stage is named after the Belgian city of Tournai . It was introduced in scientific literature by Belgian geologist André Dumont in 1832. The GSSP for

10304-505: The northwestern Gondwana margin, were affected by the subduction of the Rheic Ocean. However, they lay to west of the Ouachita orogeny and were not impacted by continental collision but became part of the active margin of the Pacific. The Moroccan margin was affected by periods of widespread dextral strike-slip deformation, magmatism and metamorphism associated with the Variscan orogeny. Towards

10416-463: The number of segments reaching their maximum number (adding during each moult) before the final moult, the animal continuing to grow while retaining the same number of segments past a certain point. Arthropleura would have had pleurites , paired sclerites between the sternite and tergite on either side of the body. They would have been beneath the paratergites and above the legs, held in place by arthrodial membrane. Pleurites have been identified in

10528-463: The palaeoequator, with all documented fossils occuring with 10° of either side of the palaeoequator during both the Carboniferous and Permian . Arthropleura has repeatedly been suggested to have been amphibious to some degree. Despite falling out of favour for many years, this idea has been bolstered by new evidence. Trackways, often found in association with coastlines, are found in both submerged and emergent substrates, showing that Arthropleura

10640-426: The peat mires. As fully marine conditions were established, limestones succeeded these marginal marine deposits. The limestones were in turn overlain by deep water black shales as maximum sea levels were reached. Ideally, this sequence would be reversed as sea levels began to fall again; however, sea level falls tend to be protracted, whilst sea level rises are rapid, ice sheets grow slowly but melt quickly. Therefore,

10752-454: The period experienced glaciations , low sea level, and mountain building as the continents collided to form Pangaea . A minor marine and terrestrial extinction event, the Carboniferous rainforest collapse , occurred at the end of the period, caused by climate change. Atmospheric oxygen levels, originally thought to be consistently higher than today throughout the Carboniferous, have been shown to be more variable, increasing from low levels at

10864-488: The preceding Devonian period, became pentadactylous during the Carboniferous. The period is sometimes called the Age of Amphibians because of the diversification of early amphibians such as the temnospondyls , which became dominant land vertebrates, as well as the first appearance of amniotes including synapsids (the clade to which modern mammals belong) and sauropsids (which include modern reptiles and birds) during

10976-459: The presence of Siphonodella sulcata below the boundary, and the presence of Siphonodella praesulcata and Siphonodella sulcata together above a local unconformity . This means the evolution of one species to the other, the definition of the boundary, is not seen at the La Serre site making precise correlation difficult. The Viséan Stage was introduced by André Dumont in 1832 and is named after

11088-877: The proto-Andes in Bolivia and western Argentina and the Pan-African mountain ranges in southeastern Brazil and southwest Africa. The main phase of the LPIA (c. 335-290 Ma) began in the late Visean, as the climate cooled and atmospheric CO 2 levels dropped. Its onset was accompanied by a global fall in sea level and widespread multimillion-year unconformities. This main phase consisted of a series of discrete several million-year-long glacial periods during which ice expanded out from up to 30 ice centres that stretched across mid- to high latitudes of Gondwana in eastern Australia, northwestern Argentina, southern Brazil, and central and Southern Africa. Isotope records indicate this drop in CO 2 levels

11200-622: The sea. Cyclothem lithologies vary from mudrock and carbonate-dominated to coarse siliciclastic sediment-dominated sequences depending on the paleo-topography, climate and supply of sediments to the shelf. The main period of cyclothem deposition occurred during the Late Paleozoic Ice Age from the Late Mississippian to early Permian, when the waxing and waning of ice sheets led to rapid changes in eustatic sea level . The growth of ice sheets led global sea levels to fall as water

11312-497: The suture between Kazakhstania and Tarim. A continental magmatic arc above a south-dipping subduction zone lay along the northern North China margin, consuming the Paleoasian Ocean. Northward subduction of the Paleo-Tethys beneath the southern margins of North China and Tarim continued during the Carboniferous, with the South Qinling block accreted to North China during the mid to late Carboniferous. No sediments are preserved from

11424-410: The thick accumulation of peat were sufficient to account for the peak in coal formation. During the Carboniferous, there was an increased rate in tectonic plate movements as the supercontinent Pangea assembled. The continents themselves formed a near circle around the opening Paleo-Tethys Ocean, with the massive Panthalassic Ocean beyond. Gondwana covered the south polar region. To its northwest

11536-544: The uplift and erosion of the more mafic basement rocks of the Central Pangea Mountains at this time, CO 2 levels dropped as low as 175 ppm and remained under 400 ppm for 10 Ma. Temperatures across the Carboniferous reflect the phases of the LPIA. At the extremes, during the Permo-Carboniferous Glacial Maximum (299-293 Ma) the global average temperature (GAT) was c. 13 °C (55 °F),

11648-487: Was Laurussia. These two continents slowly collided to form the core of Pangea. To the north of Laurussia lay Siberia and Amuria . To the east of Siberia, Kazakhstania , North China and South China formed the northern margin of the Paleo-Tethys, with Annamia laying to the south. The Central Pangean Mountains were formed during the Variscan - Alleghanian - Ouachita orogeny. Today their remains stretch over 10,000 km from

11760-427: Was amphibious, living at the bottom of lakebeds, with occasional excursions onto the land where the humidity of coal swamps allowed it to continue breathing with its supposedly trilobite-like gills. Other authors preferred a terrestrial habitat, and questioned the carnivorous diet. The juvenile specimen described by Waterlot appeared to show various plant remains within the gut tract, more recently this has been seen as

11872-500: Was complete by the Tournaisian, but subduction of the Ural Ocean between Kazakhstania and Laurussia continued until the Bashkirian when the ocean finally closed and continental collision began. Significant strike-slip movement along this zone indicates the collision was oblique. Deformation continued into the Permian and during the late Carboniferous and Permian the region was extensively intruded by granites . The Laurussian continent

11984-508: Was formed by the collision between Laurentia , Baltica and Avalonia during the Devonian. At the beginning of the Carboniferous, some models show it at the equator, whilst others place it further south. In either case, the continent drifted northwards, reaching low latitudes in the northern hemisphere by the end of the Period. The Central Pangean Mountain drew in moist air from the Paleo-Tethys Ocean resulting in heavy precipitation and

12096-646: Was lock away in glaciers. Falling sea levels exposed large tracts of the continental shelves across which river systems eroded channels and valleys and vegetation broke down the surface to form soils . The non-marine sediments deposited on this erosional surface form the base of the cyclothem. As sea levels began to rise, the rivers flowed through increasingly water-logged landscapes of swamps and lakes. Peat mires developed in these wet and oxygen-poor conditions, leading to coal formation. With continuing sea level rise, coastlines migrated landward and deltas , lagoons and esturaries developed; their sediments deposited over

12208-449: Was possibly amphibious. First discovered in 1854, Arthropleura has consistently attracted much artistic and scientific attention, yet has historically been known from mostly fragmentary remains. Prior to its description, the remains were attributed by Jordan and Meyer to a decapod crustacean . In their subsequent description of the genus, they compared it with trilobites and eurypterids . Another author, Moritz Kliver, described

12320-454: Was probably capable of walking in air and in shallow water, and did so accordingly. Additional evidence for this comes from the juvenile Montceau fossils, which demonstrate that the eyes were large and stalked, unlike any living myriapod. This condition is however known in the extinct stem-myriapod group euthycarcinoidea (with which Arthropleura sometimes co-occurs), which were aquatic to amphibious. The authors suggest that this could point to

12432-564: Was proposed by Russian stratigrapher Sofia Semikhatova in 1934. It was named after Bashkiria , the then Russian name of the republic of Bashkortostan in the southern Ural Mountains of Russia. The GSSP for the base of the Pennsylvanian Subsystem and Bashkirian Stage is located at Arrow Canyon in Nevada , US and was ratified in 1996. It is defined by the first appearance of the conodont Declinognathodus noduliferus . Arrow Canyon lay in

12544-455: Was triggered by tectonic factors with increased weathering of the growing Central Pangean Mountains and the influence of the mountains on precipitation and surface water flow. Closure of the oceanic gateway between the Rheic and Tethys oceans in the early Bashkirian also contributed to climate cooling by changing ocean circulation and heat flow patterns. Warmer periods with reduced ice volume within

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