The High Atlas , also called the Grand Atlas , is a mountain range in central Morocco , North Africa , the highest part of the Atlas Mountains .
141-683: The High Atlas rises in the west at the Atlantic Ocean and stretches in an eastern direction to the Moroccan- Algerian border. At the Atlantic and to the southwest the range drops abruptly and makes an impressive transition to the coast and the Anti-Atlas range. To the north, in the direction of Marrakech , the range descends less abruptly. The range includes Jbel Toubkal , which at 4,167 m (2.589 miles; 13,671 ft)
282-492: A World Heritage Site for their geological value, four of them are considered of "Outstanding Universal Value" based on their cultural and natural criteria: Þingvellir , Iceland; Landscape of the Pico Island Vineyard Culture , Portugal; Gough and Inaccessible Islands , United Kingdom; and Brazilian Atlantic Islands: Fernando de Noronha and Atol das Rocas Reserves, Brazil. Continental shelves in
423-672: A gothic cathedral . Among the summits at a height of 1,600 m (5,200 ft) height lies the Kasbah of Telouet on the road to Marrakech . The canyons and ravines of the Dadès and the Todra are also points of interest. Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceanic divisions , with an area of about 85,133,000 km (32,870,000 sq mi). It covers approximately 17% of Earth's surface and about 24% of its water surface area. During
564-591: A ksar ( Maghribi Arabic : قـصـر , romanized : qṣer , fortified village) still in use. The ksar is widely used in the film industry. At approximately mid-range, the Amesfrane Rock Wall rises some 1,650 feet (500 m) from a dry riverbed wadi . The formation is composed of rounded columns patterned with horizontal ridges that occurred as a result of erosion, which caused travellers to nickname it "the Cathedral", for its resemblance to
705-450: A Navy Sonic Depth Finder to draw a continuous map across the bed of the Atlantic. This involved little guesswork because the idea of sonar is straightforward with pulses being sent from the vessel, which bounce off the ocean floor, then return to the vessel. The deep ocean floor is thought to be fairly flat with occasional deeps, abyssal plains , trenches , seamounts , basins , plateaus , canyons , and some guyots . Various shelves along
846-495: A basal titanosauriform. The tracks are wide-gauge, and the grouping as close to Sauropodichnus is also supported by the manus-to-pes distance, the morphology of the manus being kidney bean-shaped, and the morphology of the pes being subtriangular. It cannot be identified whether the footprints of the herd were caused by juveniles or adults, because of the lack of previous trackway individual age identification. Generally, sauropod trackways are divided into three categories based on
987-420: A bipedal posture at times, there would be evidence of stress fractures in the forelimb 'hands'. However, none were found after they examined a large number of sauropod skeletons. Heinrich Mallison (in 2009) was the first to study the physical potential for various sauropods to rear into a tripodal stance. Mallison found that some characters previously linked to rearing adaptations were actually unrelated (such as
1128-721: A branch of the Gulf Stream which flows northward from the Grand Banks ; and the Subpolar Front , an extension of the North Atlantic Current, a wide, vaguely defined region separating the subtropical gyre from the subpolar gyre. This system of currents transports warm water into the North Atlantic, without which temperatures in the North Atlantic and Europe would plunge dramatically. North of
1269-526: A characteristic feature of all sauropods. These air spaces reduced the overall weight of the massive necks that the sauropods had, and the air-sac system in general, allowing for a single-direction airflow through stiff lungs, made it possible for the sauropods to get enough oxygen. This adaptation would have advantaged sauropods particularly in the relatively low oxygen conditions of the Jurassic and Early Cretaceous. The bird-like hollowing of sauropod bones
1410-402: A great number of adaptations in their skeletal structure. Some sauropods had as many as 19 cervical vertebrae , whereas almost all mammals are limited to only seven. Additionally, each vertebra was extremely long and had a number of empty spaces in them which would have been filled only with air. An air-sac system connected to the spaces not only lightened the long necks, but effectively increased
1551-422: A large energy saving for such a large animal. Reconstructions of the necks of Diplodocus and Apatosaurus have therefore often portrayed them in near-horizontal, so-called "neutral, undeflected posture". However, research on living animals demonstrates that almost all extant tetrapods hold the base of their necks sharply flexed when alert, showing that any inference from bones about habitual "neutral postures"
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#17327728477171692-513: A part in the different feeding and herding strategies. Since the segregation of juveniles and adults must have taken place soon after hatching, and combined with the fact that sauropod hatchlings were most likely precocial , Myers and Fiorillo concluded that species with age-segregated herds would not have exhibited much parental care. On the other hand, scientists who have studied age-mixed sauropod herds suggested that these species may have cared for their young for an extended period of time before
1833-490: A population of sauropods isolated on an island of the late Jurassic in what is now the Langenberg area of northern Germany . The diplodocoid sauropod Brachytrachelopan was the shortest member of its group because of its unusually short neck. Unlike other sauropods, whose necks could grow to up to four times the length of their backs, the neck of Brachytrachelopan was shorter than its backbone. Fossils from perhaps
1974-495: A position much above the shoulders for exploring the area or reaching higher. Another proposed function of the sauropods' long necks was essentially a radiator to deal with the extreme amount of heat produced from their large body mass. Considering that the metabolism would have been doing an immense amount of work, it would certainly have generated a large amount of heat as well, and elimination of this excess heat would have been essential for survival. It has also been proposed that
2115-483: A review of the evidence for various herd types, Myers and Fiorillo attempted to explain why sauropods appear to have often formed segregated herds. Studies of microscopic tooth wear show that juvenile sauropods had diets that differed from their adult counterparts, so herding together would not have been as productive as herding separately, where individual herd members could forage in a coordinated way. The vast size difference between juveniles and adults may also have played
2256-404: A stance to be unstable. Diplodocids, on the other hand, appear to have been well adapted for rearing up into a tripodal stance. Diplodocids had a center of mass directly over the hips, giving them greater balance on two legs. Diplodocids also had the most mobile necks of sauropods, a well-muscled pelvic girdle, and tail vertebrae with a specialised shape that would allow the tail to bear weight at
2397-455: A stilt-walker principle (suggested by amateur scientist Jim Schmidt) in which the long legs of adult sauropods allowed them to easily cover great distances without changing their overall mechanics. Along with other saurischian dinosaurs (such as theropods , including birds), sauropods had a system of air sacs , evidenced by indentations and hollow cavities in most of their vertebrae that had been invaded by them. Pneumatic, hollow bones are
2538-416: A weak Intertropical Convergence Zone , South Atlantic tropical cyclones are rare. The Atlantic Ocean is underlain mostly by dense mafic oceanic crust made up of basalt and gabbro and overlain by fine clay, silt and siliceous ooze on the abyssal plain. The continental margins and continental shelf mark lower density, but greater thickness felsic continental rock that is often much older than that of
2679-414: A wide gauge and lack of any claws or digits on the forefeet. Occasionally, only trackways from the forefeet are found. Falkingham et al. used computer modelling to show that this could be due to the properties of the substrate. These need to be just right to preserve tracks. Differences in hind limb and fore limb surface area, and therefore contact pressure with the substrate, may sometimes lead to only
2820-621: Is a complex of four water masses, two that form by deep convection in the open ocean – classical and upper Labrador sea water – and two that form from the inflow of dense water across the Greenland-Iceland-Scotland sill – Denmark Strait and Iceland-Scotland overflow water. Along its path across Earth the composition of the NADW is affected by other water masses, especially Antarctic bottom water and Mediterranean overflow water. The NADW
2961-429: Is a notable size increase among sauropodomorphs, although scanty remains of this period make interpretation conjectural. There is one definite example of a small derived sauropodomorph: Anchisaurus , under 50 kg (110 lb), even though it is closer to the sauropods than Plateosaurus and Riojasaurus , which were upwards of 1 t (0.98 long tons; 1.1 short tons) in weight. Evolving from sauropodomorphs,
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#17327728477173102-433: Is characterized by a folded domain that is dominated by NE-SW striking structural highs or ridges separating elongated and wide synclines filled by Early and Middle Jurassic sediments. Subordinate NW-SE trending structural highs bounding equal-trend synclines are also present. Cretaceous and later syntectonic Tertiary units are also locally present (e.g., Miocene-Pliocene La Cathédrale conglomerates and sandstones). During
3243-453: Is deeply unreliable. Meanwhile, computer modeling of ostrich necks has raised doubts over the flexibility needed for stationary grazing. Sauropod trackways and other fossil footprints (known as "ichnites") are known from abundant evidence present on most continents. Ichnites have helped support other biological hypotheses about sauropods, including general fore and hind foot anatomy (see Limbs and feet above). Generally, prints from
3384-898: Is evidence that they preferred wet and coastal habitats. Sauropod footprints are commonly found following coastlines or crossing floodplains, and sauropod fossils are often found in wet environments or intermingled with fossils of marine organisms. A good example of this would be the massive Jurassic sauropod trackways found in lagoon deposits on Scotland 's Isle of Skye . Studies published in 2021 suggest sauropods could not inhabit polar regions. This study suggests they were largely confined to tropical areas and had metabolisms that were very different to those of other dinosaurs, perhaps intermediate between mammals and reptiles. New studies published by Taia Wyenberg-henzler in 2022 suggest that sauropods in North America declined due to undetermined reasons in regards to their niches and distribution during
3525-467: Is fed by a flow of warm shallow water into the northern North Atlantic which is responsible for the anomalous warm climate in Europe. Changes in the formation of NADW have been linked to global climate changes in the past. Since human-made substances were introduced into the environment, the path of the NADW can be traced throughout its course by measuring tritium and radiocarbon from nuclear weapon tests in
3666-498: Is found off the eastern coast of Canada. Surface water temperatures, which vary with latitude, current systems, and season and reflect the latitudinal distribution of solar energy, range from below −2 °C (28 °F) to over 30 °C (86 °F). Maximum temperatures occur north of the equator, and minimum values are found in the polar regions. In the middle latitudes, the area of maximum temperature variations, values may vary by 7–8 °C (13–14 °F). From October to June
3807-575: Is interrupted by larger transform faults at two places: the Romanche Trench near the Equator and the Gibbs fracture zone at 53°N . The MAR is a barrier for bottom water, but at these two transform faults deep water currents can pass from one side to the other. The MAR rises 2–3 km (1.2–1.9 mi) above the surrounding ocean floor and its rift valley is the divergent boundary between
3948-854: Is intersected by two perpendicular ridges: the Azores–Gibraltar Transform Fault , the boundary between the Nubian and Eurasian plates , intersects the MAR at the Azores triple junction , on either side of the Azores microplate, near the 40°N . A much vaguer, nameless boundary, between the North American and South American plates, intersects the MAR near or just north of the Fifteen-Twenty fracture zone , approximately at 16°N . In
4089-729: Is now northern and central Brazil. The formation of the Central American Isthmus closed the Central American Seaway at the end of the Pliocene 2.8 Ma ago. The formation of the isthmus resulted in the migration and extinction of many land-living animals, known as the Great American Interchange , but the closure of the seaway resulted in a "Great American Schism" as it affected ocean currents, salinity, and temperatures in both
4230-794: Is now the Carpathian region, that were similar to the Sargasso Sea. It is possible that the population in the Sargasso Sea migrated to the Atlantic as the Tethys closed at the end of the Miocene around 17 Ma. The origin of the Sargasso fauna and flora remained enigmatic for centuries. The fossils found in the Carpathians in the mid-20th century often called the "quasi-Sargasso assemblage", finally showed that this assemblage originated in
4371-477: Is separated from the central and eastern High Atlas by the Paleozoic Massif , an area of pre-Mesozoic basement exposures located south of Marrakesh. The central and eastern High Atlas basin developed as a multiphase rift system opened toward the east by two major rift episodes occurring during Middle-Late Triassic and Early Jurassic (late Sinemurian and Pliensbachian . At present, the central High Atlas
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4512-632: Is shown in the fossil record. Moreover, it must be determined as to whether sauropod declines in North America was the result of a change in preferred flora that sauropods ate, climate, or other factors. It is also suggested in this same study that iguanodontians and hadrosauroids took advantage of recently vacated niches left by a decline in sauropod diversity during the late Jurassic and the Cretaceous in North America. Many lines of fossil evidence, from both bone beds and trackways, indicate that sauropods were gregarious animals that formed herds . However,
4653-707: Is the highest in the range and lies in Toubkal National Park . The range serves as a weather system barrier in Morocco running east–west and separating the Sahara from the Mediterranean and continental zones to the north and west. In the higher elevations of the massif, snow falls regularly, allowing winter sports . Snow lasts well into late spring in the High Atlas, mostly on the northern faces of
4794-421: Is unknown. The claw was largest (as well as tall and laterally flattened) in diplodocids, and very small in brachiosaurids, some of which seem to have lost the claw entirely based on trackway evidence. Titanosaurs may have lost the thumb claw completely (with the exception of early forms, such as Janenschia ). Titanosaurs were most unusual among sauropods, as, across their history as a clade, they lost not just
4935-867: The Iliad and the Odyssey , this all-encompassing ocean was instead known as Oceanus , the gigantic river that encircled the world; in contrast to the enclosed seas well known to the Greeks: the Mediterranean and the Black Sea. In contrast, the term "Atlantic" originally referred specifically to the Atlas Mountains in Morocco and the sea off the Strait of Gibraltar and the West African coast. The term " Aethiopian Ocean ", derived from Ancient Ethiopia ,
5076-489: The African elephant , can only reach lengths of 7.3 metres (24 ft). Others, like the brachiosaurids , were extremely tall, with high shoulders and extremely long necks. The tallest sauropod was the giant Barosaurus specimen at 22 m (72 ft) tall. By comparison, the giraffe , the tallest of all living land animals, is only 4.8 to 5.6 metres (15.74 to 18.3 ft) tall. The best evidence indicates that
5217-797: The Age of Discovery , it was known for separating the New World of the Americas ( North America and South America ) from the Old World of Afro-Eurasia ( Africa , Asia , and Europe ). Through its separation of Afro-Eurasia from the Americas, the Atlantic Ocean has played a central role in the development of human society, globalization, and the histories of many nations. While the Norse were
5358-559: The Azilal Formation developed in the margins of the central High Atlas basin, whereas the basin axis was occupied by a mixed carbonate-siliciclastic platform system prograding eastward to basinal deposits. This mixed system progressively graded to an extensive shallow water carbonate platform of the Anoual Formation , Bajocian to early Bathonian in age that is recognized throughout the central High Atlas. Finally,
5499-564: The Carpathian Basin from where it migrated over Sicily to the central Atlantic where it evolved into modern species of the Sargasso Sea. The location of the spawning ground for European eels remained unknown for decades . In the early 19th century it was discovered that the southern Sargasso Sea is the spawning ground for both the European and American eel and that the former migrate more than 5,000 km (3,100 mi) and
5640-610: The Columbian exchange while occasionally hosting naval battles. Such naval battles, as well as growing trade from regional American powers like the United States and Brazil , both increased in degree during the early 20th century, and while no major military conflicts have taken place in the Atlantic recently, the ocean remains a core component of trade around the world. The Atlantic Ocean occupies an elongated, S-shaped basin extending longitudinally between Europe and Africa to
5781-742: The Early Jurassic . Isanosaurus and Antetonitrus were originally described as Triassic sauropods, but their age, and in the case of Antetonitrus also its sauropod status, were subsequently questioned. Sauropod-like sauropodomorph tracks from the Fleming Fjord Formation ( Greenland ) might, however, indicate the occurrence of the group in the Late Triassic . By the Late Jurassic (150 million years ago), sauropods had become widespread (especially
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5922-530: The Equator . The oldest known mentions of an "Atlantic" sea come from Stesichorus around mid-sixth century BC (Sch. A. R. 1. 211): Atlantikôi pelágei (Ancient Greek: Ἀτλαντικῷ πελάγει , ' the Atlantic sea ' , etym . ' Sea of Atlas ' ) and in The Histories of Herodotus around 450 BC (Hdt. 1.202.4): Atlantis thalassa (Ancient Greek: Ἀτλαντὶς θάλασσα , ' Sea of Atlas ' or '
6063-474: The Icelandic Low produces frequent storms. Icebergs are common from early February to the end of July across the shipping lanes near the Grand Banks of Newfoundland . The ice season is longer in the polar regions, but there is little shipping in those areas. Hurricanes are a hazard in the western parts of the North Atlantic during the summer and autumn. Due to a consistently strong wind shear and
6204-684: The North American and Eurasian plates in the North Atlantic and the South American and African plates in the South Atlantic. The MAR produces basaltic volcanoes in Eyjafjallajökull , Iceland, and pillow lava on the ocean floor. The depth of water at the apex of the ridge is less than 2,700 m (1,500 fathoms ; 8,900 ft ) in most places, while the bottom of the ridge is three times as deep. The MAR
6345-616: The North Atlantic Drift is thought to have at least some influence on climate. For example, the Gulf Stream helps moderate winter temperatures along the coastline of southeastern North America, keeping it warmer in winter along the coast than inland areas. The Gulf Stream also keeps extreme temperatures from occurring on the Florida Peninsula. In the higher latitudes, the North Atlantic Drift, warms
6486-514: The North Atlantic oscillation , occurs. On average, the Atlantic is the saltiest major ocean; surface water salinity in the open ocean ranges from 33 to 37 parts per thousand (3.3–3.7%) by mass and varies with latitude and season. Evaporation, precipitation, river inflow and sea ice melting influence surface salinity values. Although the lowest salinity values are just north of the equator (because of heavy tropical rainfall), in general,
6627-555: The Scotia Sea , and other tributary water bodies. Including these marginal seas the coast line of the Atlantic measures 111,866 km (69,510 mi) compared to 135,663 km (84,297 mi) for the Pacific. Including its marginal seas, the Atlantic covers an area of 106,460,000 km (41,100,000 sq mi) or 23.5% of the global ocean and has a volume of 310,410,900 km (74,471,500 cu mi) or 23.3% of
6768-534: The Toarcian and Bathonian deposits of this range, respectively. In 2023, a fossil of a hybodontiform Strophodus was collected from the Bajocian deposits of High Atlas. It's the oldest Gondwanan specimen of this genus at the time of discovery. The new species was named Strophodus atlasensis , after the mountain range where its holotype was found. At the foot of the High Atlas one finds Aït Benhaddou ,
6909-568: The Triassic , the central High Atlas extensional basin was characterized by the synrift deposition of red beds and localized evaporites capped by extensive basaltic lava flows . Following the Triassic red bed deposition, marine conditions prevailed during the Early and Middle Jurassic resulting in the development of carbonate and mixed depositional systems. The Jurassic Atlas basin was open to
7050-473: The blue whale in size. The weight of Amphicoelias fragillimus was estimated at 122.4 metric tons with lengths of up to nearly 60 meters but 2015 research argued that these estimates were based on a diplodocid rather than the more modern rebbachisaurid, suggesting a much shorter length of 35–40 meters with mass between 80–120 tons. Additional finds indicate a number of species likely reached or exceeded weights of 40 tons. The largest land animal alive today,
7191-430: The bush elephant , weighs no more than 10.4 metric tons (11.5 short tons). Among the smallest sauropods were the primitive Ohmdenosaurus (4 m, or 13 ft long), the dwarf titanosaur Magyarosaurus (6 m or 20 ft long), and the dwarf brachiosaurid Europasaurus , which was 6.2 meters long as a fully-grown adult. Its small stature was probably the result of insular dwarfism occurring in
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#17327728477177332-555: The diplodocids and brachiosaurids ). By the Late Cretaceous , one group of sauropods, the titanosaurs , had replaced all others and had a near-global distribution. However, as with all other non-avian dinosaurs alive at the time, the titanosaurs died out in the Cretaceous–Paleogene extinction event . Fossilised remains of sauropods have been found on every continent, including Antarctica . The name Sauropoda
7473-638: The meridional overturning circulation (MOC), the northward heat transport of which is threatened by anthropogenic climate change. Large variations in the subpolar gyre on a decade-century scale, associated with the North Atlantic oscillation , are especially pronounced in Labrador Sea Water , the upper layers of the MOC. The South Atlantic is dominated by the anti-cyclonic southern subtropical gyre. The South Atlantic Central Water originates in this gyre, while Antarctic Intermediate Water originates in
7614-497: The rorquals , such as the blue whale . But, unlike whales, sauropods were primarily terrestrial animals . Their body structure did not vary as much as other dinosaurs, perhaps due to size constraints, but they displayed ample variety. Some, like the diplodocids , possessed tremendously long tails, which they may have been able to crack like a whip as a signal or to deter or injure predators, or to make sonic booms . Supersaurus , at 33 to 34 metres (108 to 112 ft) long,
7755-718: The tectonic inversion of the Late Triassic to Middle Jurassic rift basin during the Cenozoic convergence between the African and Eurasian Plates . The Moroccan Atlas is formed by the ENE-WSW-striking High Atlas and the NE-SW-trending Middle Atlas. The former is divided into three segments named western, central, and eastern High Atlas. The western High Atlas was part of the Atlantic Jurassic passive margin and
7896-458: The thermocline of the subtropical gyre. The Sargasso Sea in the western North Atlantic can be defined as the area where two species of Sargassum ( S. fluitans and natans ) float, an area 4,000 km (2,500 mi) wide and encircled by the Gulf Stream , North Atlantic Drift , and North Equatorial Current . This population of seaweed probably originated from Tertiary ancestors on
8037-400: The 1870s, the Challenger expedition discovered parts of what is now known as the Mid-Atlantic Ridge, or: An elevated ridge rising to an average height of about 1,900 fathoms [3,500 m; 11,400 ft] below the surface traverses the basins of the North and South Atlantic in a meridianal direction from Cape Farewell, probably its far south at least as Gough Island, following roughly
8178-434: The 1953 definition it extends south to Antarctica, while in later maps it is bounded at the 60° parallel by the Southern Ocean. The Atlantic has irregular coasts indented by numerous bays, gulfs and seas. These include the Baltic Sea , Black Sea , Caribbean Sea , Davis Strait , Denmark Strait , part of the Drake Passage , Gulf of Mexico , Labrador Sea , Mediterranean Sea , North Sea , Norwegian Sea , almost all of
8319-411: The 1960s and CFCs . The clockwise warm-water North Atlantic Gyre occupies the northern Atlantic, and the counter-clockwise warm-water South Atlantic Gyre appears in the southern Atlantic. In the North Atlantic, surface circulation is dominated by three inter-connected currents: the Gulf Stream which flows north-east from the North American coast at Cape Hatteras ; the North Atlantic Current ,
8460-458: The 1970s, the effects of sauropod air sacs on their supposed aquatic lifestyle began to be explored. Paleontologists such as Coombs and Bakker used this, as well as evidence from sedimentology and biomechanics , to show that sauropods were primarily terrestrial animals. In 2004, D.M. Henderson noted that, due to their extensive system of air sacs, sauropods would have been buoyant and would not have been able to submerge their torsos completely below
8601-432: The 19th and early 20th centuries concluded that sauropods were too large to have supported their weight on land, and therefore that they must have been mainly aquatic . Most life restorations of sauropods in art through the first three quarters of the 20th century depicted them fully or partially immersed in water. This early notion was cast in doubt beginning in the 1950s, when a study by Kermack (1951) demonstrated that, if
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#17327728477178742-456: The Atlantic and Pacific. Marine organisms on both sides of the isthmus became isolated and either diverged or went extinct. Sauropoda Sauropoda ( / s ɔː ˈ r ɒ p ə d ə / ), whose members are known as sauropods ( / ˈ s ɔːr ə p ɒ d z / ; from sauro- + -pod , ' lizard -footed'), is a clade of saurischian ('lizard-hipped') dinosaurs . Sauropods had very long necks, long tails, small heads (relative to
8883-407: The Atlantic are wide off Newfoundland, southernmost South America, and northeastern Europe. In the western Atlantic carbonate platforms dominate large areas, for example, the Blake Plateau and Bermuda Rise . The Atlantic is surrounded by passive margins except at a few locations where active margins form deep trenches : the Puerto Rico Trench (8,376 m or 27,480 ft maximum depth) in
9024-468: The Atlantic include the Challenger expedition and the German Meteor expedition ; as of 2001 , Columbia University 's Lamont–Doherty Earth Observatory and the United States Navy Hydrographic Office conduct research on the ocean. The MAR divides the Atlantic longitudinally into two halves, in each of which a series of basins are delimited by secondary, transverse ridges. The MAR reaches above 2,000 m (6,600 ft) along most of its length, but
9165-403: The Atlantic north of the equator. The coldest zones are in high latitudes, with the coldest regions corresponding to the areas covered by sea ice. Ocean currents influence the climate by transporting warm and cold waters to other regions. The winds that are cooled or warmed when blowing over these currents influence adjacent land areas. The Gulf Stream and its northern extension towards Europe,
9306-455: The Atlantic sea ' ) where the name refers to "the sea beyond the pillars of Heracles " which is said to be part of the sea that surrounds all land. In these uses, the name refers to Atlas , the Titan in Greek mythology , who supported the heavens and who later appeared as a frontispiece in medieval maps and also lent his name to modern atlases . On the other hand, to early Greek sailors and in ancient Greek mythological literature such as
9447-409: The Bahamas, while coarse river outwash sands and silt are common in shallow shelf areas like the Georges Bank . Coarse sand, boulders, and rocks were transported into some areas, such as off the coast of Nova Scotia or the Gulf of Maine during the Pleistocene ice ages. The break-up of Pangaea began in the central Atlantic, between North America and Northwest Africa, where rift basins opened during
9588-404: The European shores of the former Tethys Ocean and has, if so, maintained itself by vegetative growth , floating in the ocean for millions of years. Other species endemic to the Sargasso Sea include the sargassum fish , a predator with algae-like appendages which hovers motionless among the Sargassum . Fossils of similar fishes have been found in fossil bays of the former Tethys Ocean, in what
9729-405: The Late Triassic and Early Jurassic. This period also saw the first stages of the uplift of the Atlas Mountains. The exact timing is controversial with estimates ranging from 200 to 170 Ma. The opening of the Atlantic Ocean coincided with the initial break-up of the supercontinent Pangaea , both of which were initiated by the eruption of the Central Atlantic Magmatic Province (CAMP), one of
9870-401: The Middle Triassic of Argentina, weighed approximately 1 kg (2.2 lb) or less. These evolved into saurischia, which saw a rapid increase of bauplan size, although more primitive members like Eoraptor , Panphagia , Pantydraco , Saturnalia and Guaibasaurus still retained a moderate size, possibly under 10 kg (22 lb). Even with these small, primitive forms, there
10011-468: The North Atlantic Gyre, the cyclonic North Atlantic Subpolar Gyre plays a key role in climate variability. It is governed by ocean currents from marginal seas and regional topography, rather than being steered by wind, both in the deep ocean and at sea level. The subpolar gyre forms an important part of the global thermohaline circulation . Its eastern portion includes eddying branches of the North Atlantic Current which transport warm, saline waters from
10152-437: The South Atlantic, and the "Atmospheric Bridge", which evaporates subtropical Atlantic waters and exports it to the Pacific. The Atlantic Ocean consists of four major, upper water masses with distinct temperature and salinity. The Atlantic subarctic upper water in the northernmost North Atlantic is the source for subarctic intermediate water and North Atlantic intermediate water. North Atlantic central water can be divided into
10293-550: The airflow through the trachea, helping the creatures to breathe in enough air. By evolving vertebrae consisting of 60% air, the sauropods were able to minimize the amount of dense, heavy bone without sacrificing the ability to take sufficiently large breaths to fuel the entire body with oxygen. According to Kent Stevens, computer-modeled reconstructions of the skeletons made from the vertebrae indicate that sauropod necks were capable of sweeping out large feeding areas without needing to move their bodies, but were unable to be retracted to
10434-418: The animal were submerged in several metres of water, the pressure would be enough to fatally collapse the lungs and airway. However, this and other early studies of sauropod ecology were flawed in that they ignored a substantial body of evidence that the bodies of sauropods were heavily permeated with air sacs . In 1878, paleontologist E.D. Cope had even referred to these structures as "floats". Beginning in
10575-475: The atmosphere over the oceans, keeping the British Isles and northwestern Europe mild and cloudy, and not severely cold in winter, like other locations at the same high latitude. The cold water currents contribute to heavy fog off the coast of eastern Canada (the Grand Banks of Newfoundland area) and Africa's northwestern coast. In general, winds transport moisture and air over land areas. Every winter,
10716-479: The basin. Pliensbachian carbonate platforms preferentially developed in the margins basin and in synsedimentary structural highs, promoting abrupt transitions in the marine sedimentary record from shallow water to basinal facies. Global anoxia during the latest Pliensbachian and the earliest Toarcian occurred in close association with regional drowning of the lower Liassic platforms and localized deposition of basinal marls. From Toarcian times, carbonate platforms of
10857-605: The community and their living system. There are two types of Alpine Climates in the High Atlas: In the west lies the oldest portion of the range. Its high point is the Jbel Toubkal, which is visible from the city of Marrakech . Jbel Toubkal lies in the Toubkal national park, which was created in 1942. The massif consists of Jurassic and Cretaceous formations notched by deep erosion-carved valleys. This part of
10998-499: The contrasting landscapes are similar to Colorado in the United States , with high plateaux, gorges and box canyons , and peaks sometimes splintered by erosion. Several peaks in this area exceed 4,000 m (13,000 ft), with Jbel Mgoun at 4068 m being the highest peak in this part of the High Atlas. The area is populated by Berbers . The eastern part of the High Atlas forms vast plateaux at high altitude which provide
11139-675: The discovery of the bones of a dinosaur called ' Atlasaurus ', which populated Morocco 180 million years ago. This dinosaur is also named Tazoudasaurus , after the name of the village of Tazouda , where it was discovered. The creature, about 15 metres (49 feet) long, is postulated to be an ancestor of the Sauropoda found in America. Until 140 million years ago, the African and American continents were connected. The Atlas Mountains define an ENE-WSW trending intracontinental belt, resulting from
11280-523: The distance between opposite limbs: narrow gauge, medium gauge, and wide gauge. The gauge of the trackway can help determine how wide-set the limbs of various sauropods were and how this may have impacted the way they walked. A 2004 study by Day and colleagues found that a general pattern could be found among groups of advanced sauropods, with each sauropod family being characterised by certain trackway gauges. They found that most sauropods other than titanosaurs had narrow-gauge limbs, with strong impressions of
11421-498: The east (western Tethys realm) with Paleozoic provenance areas located toward the west and south. Liassic sedimentary systems evolved from extensive peritidal shallow water carbonate platforms ( Hettangian -lower Sinemurian ) that progressively backstepped toward the basin margins, to more localized platform development flanking the depocenters (Sinemurian). Normal faulting and block tilting increased notably during Pliensbachian times, resulting in north to south compartmentalization of
11562-670: The east, and the Americas to the west. As one component of the interconnected World Ocean , it is connected in the north to the Arctic Ocean , to the Pacific Ocean in the southwest, the Indian Ocean in the southeast, and the Southern Ocean in the south. Other definitions describe the Atlantic as extending southward to Antarctica . The Atlantic Ocean is divided in two parts, the northern and southern Atlantic, by
11703-615: The east, the boundaries of the ocean proper are Europe: the Strait of Gibraltar (where it connects with the Mediterranean Sea – one of its marginal seas – and, in turn, the Black Sea , both of which also touch upon Asia) and Africa. In the southeast, the Atlantic merges into the Indian Ocean. The 20° East meridian , running south from Cape Agulhas to Antarctica defines its border. In
11844-544: The eastern and western North Atlantic central water since the western part is strongly affected by the Gulf Stream and therefore the upper layer is closer to underlying fresher subpolar intermediate water. The eastern water is saltier because of its proximity to Mediterranean water. North Atlantic central water flows into South Atlantic central water at 15°N . There are five intermediate waters: four low-salinity waters formed at subpolar latitudes and one high-salinity formed through evaporation. Arctic intermediate water flows from
11985-405: The end of the Jurassic and into the latest Cretaceous. Why this is remains unclear, but some similarities in feeding niches between iguanodontians, hadrosauroids and sauropods have been suggested and may have resulted in some competition. However, this cannot fully explain the full decline in distribution of sauropods, as competitive exclusion would have resulted in a much more rapid decline than what
12126-423: The external claw but also completely lost the digits of the front foot. Advanced titanosaurs had no digits or digit bones, and walked only on horseshoe-shaped "stumps" made up of the columnar metacarpal bones. Print evidence from Portugal shows that, in at least some sauropods (probably brachiosaurids), the bottom and sides of the forefoot column was likely covered in small, spiny scales, which left score marks in
12267-493: The first known humans to cross the Atlantic, it was the expedition of Christopher Columbus in 1492 that proved to be the most consequential. Columbus' expedition ushered in an age of exploration and colonization of the Americas by European powers , most notably Portugal , Spain , France , and the United Kingdom . From the 16th to 19th centuries, the Atlantic Ocean was the center of both an eponymous slave trade and
12408-488: The flesh miss these facts, inaccurately depicting sauropods with hooves capping the claw-less digits of the feet, or more than three claws or hooves on the hands. The proximal caudal vertebrae are extremely diagnostic for sauropods. The sauropods' most defining characteristic was their size. Even the dwarf sauropods (perhaps 5 to 6 metres, or 20 feet long) were counted among the largest animals in their ecosystem . Their only real competitors in terms of size are
12549-601: The forefeet are much smaller than the hind feet, and often crescent-shaped. Occasionally ichnites preserve traces of the claws, and help confirm which sauropod groups lost claws or even digits on their forefeet. Sauropod tracks from the Villar del Arzobispo Formation of early Berriasian age in Spain support the gregarious behaviour of the group. The tracks are possibly more similar to Sauropodichnus giganteus than any other ichnogenera, although they have been suggested to be from
12690-483: The forefeet trackways being preserved. In a study published in PLoS ONE on October 30, 2013, by Bill Sellers , Rodolfo Coria , Lee Margetts et al. , Argentinosaurus was digitally reconstructed to test its locomotion for the first time. Before the study, the most common way of estimating speed was through studying bone histology and ichnology . Commonly, studies about sauropod bone histology and speed focus on
12831-418: The forefoot bone ( metacarpal ) columns in eusauropods was semi-circular, so sauropod forefoot prints are horseshoe-shaped. Unlike elephants, print evidence shows that sauropods lacked any fleshy padding to back the front feet, making them concave. The only claw visible in most sauropods was the distinctive thumb claw (associated with digit I). Almost all sauropods had such a claw, though what purpose it served
12972-401: The gait and speed of Argentinosaurus , the study performed a musculoskeletal analysis. The only previous musculoskeletal analyses were conducted on hominoids , terror birds , and other dinosaurs . Before they could conduct the analysis, the team had to create a digital skeleton of the animal in question, show where there would be muscle layering, locate the muscles and joints, and finally find
13113-447: The head in such a posture for long would have used some half of its energy intake. Further, to move blood to such a height—dismissing posited auxiliary hearts in the neck —would require a heart 15 times as large as of a similar-sized whale. The above have been used to argue that the long neck must instead have been held more or less horizontally, presumed to enable feeding on plants over a wide area with less need to move about, yielding
13254-526: The headwaters for the Moulouya River . It extends from the town of Khenifra . This portion of the range includes the solid mass of the Tamlelt whose northern edge is occupied by its higher peaks, such Jbel Ayachi at 3,747 m (12,293 ft). The altitude falls towards the east where the mountains join the pre-Saharan zone. This massif became an internationally famous paleontological site after
13395-490: The history of their study, scientists, such as Osborn , have speculated that sauropods could rear up on their hind legs, using the tail as the third 'leg' of a tripod. A skeletal mount depicting the diplodocid Barosaurus lentus rearing up on its hind legs at the American Museum of Natural History is one illustration of this hypothesis. In a 2005 paper, Rothschild and Molnar reasoned that if sauropods had adopted
13536-418: The large thumb claw on the forefeet. Medium gauge trackways with claw impressions on the forefeet probably belong to brachiosaurids and other primitive titanosauriformes , which were evolving wider-set limbs but retained their claws. Primitive true titanosaurs also retained their forefoot claw but had evolved fully wide gauge limbs. Wide gauge limbs were retained by advanced titanosaurs, trackways from which show
13677-600: The largest dinosaur ever found were discovered in 2012 in the Neuquén Province of northwest Patagonia, Argentina. It is believed that they are from a titanosaur, which were amongst the largest sauropods. On or shortly before 29 March 2017 a sauropod footprint about 5.6 feet (1.7 meters) long was found at Walmadany in the Kimberley Region of Western Australia. The report said that it was the biggest known yet. In 2020 Molina-Perez and Larramendi estimated
13818-454: The latter 2,000 km (1,200 mi). Ocean currents such as the Gulf Stream transport eel larvae from the Sargasso Sea to foraging areas in North America, Europe, and northern Africa. Recent but disputed research suggests that eels possibly use Earth's magnetic field to navigate through the ocean both as larvae and as adults. The climate is influenced by the temperatures of the surface waters and water currents as well as winds. Because of
13959-666: The limits of the oceans and seas in 1953, but some of these definitions have been revised since then and some are not recognized by various authorities, institutions, and countries, for example the CIA World Factbook . Correspondingly, the extent and number of oceans and seas vary. The Atlantic Ocean is bounded on the west by North and South America. It connects to the Arctic Ocean through the Denmark Strait , Greenland Sea , Norwegian Sea and Barents Sea . To
14100-462: The long necks would have cooled the veins and arteries going to the brain, avoiding excessively heated blood from reaching the head. It was in fact found that the increase in metabolic rate resulting from the sauropods' necks was slightly more than compensated for by the extra surface area from which heat could dissipate. When sauropods were first discovered, their immense size led many scientists to compare them with modern-day whales . Most studies in
14241-501: The lowest values are in the high latitudes and along coasts where large rivers enter. Maximum salinity values occur at about 25° north and south , in subtropical regions with low rainfall and high evaporation. The high surface salinity in the Atlantic, on which the Atlantic thermohaline circulation is dependent, is maintained by two processes: the Agulhas Leakage/Rings , which brings salty Indian Ocean waters into
14382-597: The makeup of the herds varied between species. Some bone beds, for example a site from the Middle Jurassic of Argentina , appear to show herds made up of individuals of various age groups, mixing juveniles and adults. However, a number of other fossil sites and trackways indicate that many sauropod species travelled in herds segregated by age, with juveniles forming herds separate from adults. Such segregated herding strategies have been found in species such as Alamosaurus , Bellusaurus and some diplodocids . In
14523-514: The margins of the continents constitute about 11% of the bottom topography with few deep channels cut across the continental rise. The mean depth between 60°N and 60°S is 3,730 m (12,240 ft), or close to the average for the global ocean, with a modal depth between 4,000 and 5,000 m (13,000 and 16,000 ft). In the South Atlantic the Walvis Ridge and Rio Grande Rise form barriers to ocean currents. The Laurentian Abyss
14664-664: The maximum depth, the Milwaukee Deep in the Puerto Rico Trench , is 8,376 m (27,480 ft). Top large seas: The bathymetry of the Atlantic is dominated by a submarine mountain range called the Mid-Atlantic Ridge (MAR). It runs from 87°N or 300 km (190 mi) south of the North Pole to the subantarctic Bouvet Island at 54°S . Expeditions to explore the bathymertry of
14805-567: The middle Dogger to Lower Cretaceous red beds record the sedimentation of continental to shallow marine transitional deposits that characterize the central High Atlas domain. Fully marine environmental conditions and platform carbonate deposits, which locally crop out in the margins of the Atlas System, dominated between Aptian and Cenomanian times. Fossils of Mesozoic animals are known from High Atlas. Remains of sauropod dinosaurs Tazoudasaurus and Atlasaurus were found in
14946-732: The most extensive and voluminous large igneous provinces in Earth's history associated with the Triassic–Jurassic extinction event , one of Earth's major extinction events . Theoliitic dikes , sills , and lava flows from the CAMP eruption at 200 Ma have been found in West Africa, eastern North America, and northern South America. The extent of the volcanism has been estimated to 4.5 × 10 km (1.7 × 10 sq mi) of which 2.5 × 10 km (9.7 × 10 sq mi) covered what
15087-519: The most massive were Argentinosaurus (65–80 metric tons ), Mamenchisaurus sinocanadorum (60-80 metric tons ), the giant Barosaurus specimen (60-80+ metric tons ) and Patagotitan with Puertasaurus (50-55 metric tons ). Meanwhile, 'mega-sauropods' such as Bruhathkayosaurus has long been scrutinized due to controversial debates on its validity, but recent photos re-surfacing in 2022 have legitimized it, allowing for more updated estimates that range between 110–170 tons, rivaling
15228-641: The muscle properties before finding the gait and speed. The results of the biomechanics study revealed that Argentinosaurus was mechanically competent at a top speed of 2 m/s (5 mph) given the great weight of the animal and the strain that its joints were capable of bearing. The results further revealed that much larger terrestrial vertebrates might be possible, but would require significant body remodeling and possible sufficient behavioral change to prevent joint collapse. Sauropods were gigantic descendants of surprisingly small ancestors. Basal dinosauriformes, such as Pseudolagosuchus and Marasuchus from
15369-431: The neck, and the head was evolved to be very small and light, losing the ability to orally process food. By reducing their heads to simple harvesting tools that got the plants into the body, the sauropods needed less power to lift their heads, and thus were able to develop necks with less dense muscle and connective tissue. This drastically reduced the overall mass of the neck, enabling further elongation. Sauropods also had
15510-571: The north to become the source for North Atlantic deep water, south of the Greenland-Scotland sill. These two intermediate waters have different salinity in the western and eastern basins. The wide range of salinities in the North Atlantic is caused by the asymmetry of the northern subtropical gyre and a large number of contributions from a wide range of sources: Labrador Sea, Norwegian-Greenland Sea, Mediterranean, and South Atlantic Intermediate Water. The North Atlantic deep water (NADW)
15651-425: The ocean's great capacity to store and release heat, maritime climates are more moderate and have less extreme seasonal variations than inland climates. Precipitation can be approximated from coastal weather data and air temperature from water temperatures. The oceans are the major source of atmospheric moisture that is obtained through evaporation. Climatic zones vary with latitude; the warmest zones stretch across
15792-627: The outlines of the coasts of the Old and the New Worlds. The remainder of the ridge was discovered in the 1920s by the German Meteor expedition using echo-sounding equipment. The exploration of the MAR in the 1950s led to the general acceptance of seafloor spreading and plate tectonics . Most of the MAR runs under water but where it reaches the surfaces it has produced volcanic islands. While nine of these have collectively been nominated
15933-584: The point it touched the ground. Mallison concluded that diplodocids were better adapted to rearing than elephants , which do so occasionally in the wild. He also argues that stress fractures in the wild do not occur from everyday behaviour, such as feeding-related activities (contra Rothschild and Molnar). There is little agreement over how sauropods held their heads and necks, and the postures they could achieve in life. Whether sauropods' long necks could be used for browsing high trees has been questioned based on calculations suggesting that just pumping blood up to
16074-651: The pond" or "on the other side of the pond" or "across the pond", rather than to discuss the ocean itself. The term dates to 1640, first appearing in print in a pamphlet released during the reign of Charles I , and reproduced in 1869 in Nehemiah Wallington 's Historical Notices of Events Occurring Chiefly in The Reign of Charles I , where "great Pond" is used in reference to the Atlantic Ocean by Francis Windebank , Charles I's Secretary of State . The International Hydrographic Organization (IHO) defined
16215-532: The postcranial skeleton, which holds many unique features, such as an enlarged process on the ulna , a wide lobe on the ilia , an inward-slanting top third of the femur , and an extremely ovoid femur shaft. Those features are useful when attempting to explain trackway patterns of graviportal animals. When studying ichnology to calculate sauropod speed, there are a few problems, such as only providing estimates for certain gaits because of preservation bias , and being subject to many more accuracy problems. To estimate
16356-642: The prints. In titanosaurs, the ends of the metacarpal bones that contacted the ground were unusually broad and squared-off, and some specimens preserve the remains of soft tissue covering this area, suggesting that the front feet were rimmed with some kind of padding in these species. Matthew Bonnan has shown that sauropod dinosaur long bones grew isometrically : that is, there was little to no change in shape as juvenile sauropods became gigantic adults. Bonnan suggested that this odd scaling pattern (most vertebrates show significant shape changes in long bones associated with increasing weight support) might be related to
16497-767: The range includes the Ourika Valley , which is the only location in the High Atlas where the endangered primate , the Barbary macaque , Macaca sylvanus , is found; however, this primate is also found in parts of the Middle Atlas and the Rif , as well as parts of Algeria . The Ourika Valley is also a location where a diverse flora was recorded as early as the 19th century. A solid chalk mass morphologically dominated by tabular zones reaching an altitude of 2,500 m (8,200 ft) extends from Azilal to Ouarzazate. Here,
16638-566: The range. On the Western High Atlas, there is Oukaïmeden , one of three main ski stations in Morocco. The High Atlas forms the basins for a multiplicity of river systems. The majority of the year-round rivers flow to the north, providing the basis for the settlements there. A number of wadis and seasonal rivers terminate in the deserts to the south and plateaux to the east of the mountains. The High-Atlas Mountains are inhabited by Berbers, who live from agriculture and pastoralism in
16779-422: The rest of their body), and four thick, pillar-like legs. They are notable for the enormous sizes attained by some species, and the group includes the largest animals to have ever lived on land. Well-known genera include Apatosaurus , Argentinosaurus , Alamosaurus , Brachiosaurus , Camarasaurus , Diplodocus , and Mamenchisaurus . The oldest known unequivocal sauropod dinosaurs are known from
16920-621: The sauropods were huge. Their giant size probably resulted from an increased growth rate made possible by tachymetabolic endothermy , a trait which evolved in sauropodomorphs. Once branched into sauropods, sauropodomorphs continued steadily to grow larger, with smaller sauropods, like the Early Jurassic Barapasaurus and Kotasaurus , evolving into even larger forms like the Middle Jurassic Mamenchisaurus and Patagosaurus . Responding to
17061-401: The scientists, the specializing of their diets helped the different herbivorous dinosaurs to coexist. Sauropod necks have been found at over 15 metres (49 ft) in length, a full six times longer than the world record giraffe neck. Enabling this were a number of essential physiological features. The dinosaurs' overall large body size and quadrupedal stance provided a stable base to support
17202-438: The seafloor. The oldest oceanic crust in the Atlantic is up to 145 million years and is situated off the west coast of Africa and the east coast of North America, or on either side of the South Atlantic. In many places, the continental shelf and continental slope are covered in thick sedimentary layers. For instance, on the North American side of the ocean, large carbonate deposits formed in warm shallow waters such as Florida and
17343-451: The shorter hind legs free of the bottom, and using the front limbs to punt forward. However, due to their body proportions, floating sauropods would also have been very unstable and maladapted for extended periods in the water. This mode of aquatic locomotion , combined with its instability, led Henderson to refer to sauropods in water as "tipsy punters". While sauropods could therefore not have been aquatic as historically depicted, there
17484-409: The sides to create a wide foot as in elephants, the manus bones of sauropods were arranged in fully vertical columns, with extremely reduced finger bones (though it is not clear if the most primitive sauropods, such as Vulcanodon and Barapasaurus , had such forefeet). The front feet were so modified in eusauropods that individual digits would not have been visible in life. The arrangement of
17625-477: The size estimates of A. fragillimus may have been highly exaggerated. The longest dinosaur known from reasonable fossils material is probably Argentinosaurus huinculensis with length estimates of 35 metres (115 ft) to 36 metres (118 ft) according to the most recent researches. However the giant Barosaurus specimen BYU 9024 might have been even larger reaching lengths of 45–48 meters (148–157 ft). The longest terrestrial animal alive today,
17766-537: The size of the animal at 31 meters (102 ft) and 72 tonnes (79.4 short tons) based on the 1.75 meter (5.7 ft) long footprint. As massive quadrupeds , sauropods developed specialized "graviportal" (weight-bearing) limbs. The hind feet were broad, and retained three claws in most species. Particularly unusual compared with other animals were the highly modified front feet ( manus ). The front feet of sauropods were very dissimilar from those of modern large quadrupeds, such as elephants . Rather than splaying out to
17907-551: The subtropics to the northeastern Atlantic. There this water is cooled during winter and forms return currents that merge along the eastern continental slope of Greenland where they form an intense (40–50 Sv ) current which flows around the continental margins of the Labrador Sea . A third of this water becomes part of the deep portion of the North Atlantic Deep Water (NADW). The NADW, in turn, feeds
18048-421: The surface is usually covered with sea ice in the Labrador Sea , Denmark Strait , and Baltic Sea. The Coriolis effect circulates North Atlantic water in a clockwise direction, whereas South Atlantic water circulates counter-clockwise. The south tides in the Atlantic Ocean are semi-diurnal; that is, two high tides occur every 24 lunar hours. In latitudes above 40° North some east–west oscillation, known as
18189-467: The surface of the water; in other words, they would float, and would not have been in danger of lung collapse due to water pressure when swimming. Evidence for swimming in sauropods comes from fossil trackways that have occasionally been found to preserve only the forefeet (manus) impressions. Henderson showed that such trackways can be explained by sauropods with long forelimbs (such as macronarians ) floating in relatively shallow water deep enough to keep
18330-434: The tip, narrow at the neck) teeth. They had tiny heads, massive bodies, and most had long tails. Their hind legs were thick, straight, and powerful, ending in club-like feet with five toes, though only the inner three (or in some cases four) bore claws. Their forelimbs were rather more slender and typically ended in pillar-like hands built for supporting weight; often only the thumb bore a claw. Many illustrations of sauropods in
18471-413: The tooth affected how long it took for a new tooth to grow. Camarasaurus 's teeth took longer to grow than those for Diplodocus because they were larger. It was also noted by D'Emic and his team that the differences between the teeth of the sauropods also indicated a difference in diet. Diplodocus ate plants low to the ground and Camarasaurus browsed leaves from top and middle branches. According to
18612-428: The total volume of the Earth's oceans. Excluding its marginal seas, the Atlantic covers 81,760,000 km (31,570,000 sq mi) and has a volume of 305,811,900 km (73,368,200 cu mi). The North Atlantic covers 41,490,000 km (16,020,000 sq mi) (11.5%) and the South Atlantic 40,270,000 km (15,550,000 sq mi) (11.1%). The average depth is 3,646 m (11,962 ft) and
18753-582: The upper layers of the circumpolar region, near the Drake Passage and the Falkland Islands. Both these currents receive some contribution from the Indian Ocean. On the African east coast, the small cyclonic Angola Gyre lies embedded in the large subtropical gyre. The southern subtropical gyre is partly masked by a wind-induced Ekman layer . The residence time of the gyre is 4.4–8.5 years. North Atlantic Deep Water flows southward below
18894-610: The valleys. In the steppe zone of the High-Atlas, where precipitations are low, the locals created a smart technique in managing the low precipitations and the weak soil. They turn the rather semi-arid lands into fertile valleys called locally by Agdal (garden in Berber). This technique has intrigued many Western agriculturalists, in which they were impressed by the high efficiency of this agricultural system. Many scientists, particularly French scientists, make yearly expeditions to observe
19035-424: The western Atlantic and South Sandwich Trench (8,264 m or 27,113 ft) in the South Atlantic. There are numerous submarine canyons off northeastern North America, western Europe, and northwestern Africa. Some of these canyons extend along the continental rises and farther into the abyssal plains as deep-sea channels. In 1922, a historic moment in cartography and oceanography occurred. The USS Stewart used
19176-415: The wide-set hip bones of titanosaurs ) or would have hindered rearing. For example, titanosaurs had an unusually flexible backbone, which would have decreased stability in a tripodal posture and would have put more strain on the muscles. Likewise, it is unlikely that brachiosaurids could rear up onto the hind legs, as their center of gravity was much farther forward than other sauropods, which would cause such
19317-433: The young reached adulthood. A 2014 study suggested that the time from laying the egg to the time of the hatching was likely to have been between 65 and 82 days. Exactly how segregated versus age-mixed herding varied across different groups of sauropods is unknown. Further examples of gregarious behavior will need to be discovered from more sauropod species to begin detecting possible patterns of distribution. Since early in
19458-494: Was applied to the southern Atlantic as late as the mid-19th century. During the Age of Discovery , the Atlantic was also known to English cartographers as the Great Western Ocean . The pond is a term often used by British and American speakers in reference to the northern Atlantic Ocean, as a form of meiosis , or ironic understatement. It is used mostly when referring to events or circumstances "on this side of
19599-603: Was coined by Othniel Charles Marsh in 1878, and is derived from Ancient Greek , meaning "lizard foot". Sauropods are one of the most recognizable groups of dinosaurs, and have become a fixture in popular culture due to their impressive size. Complete sauropod fossil finds are extremely rare. Many species, especially the largest, are known only from isolated and disarticulated bones. Many near-complete specimens lack heads, tail tips and limbs. Sauropods were herbivorous (plant-eating), usually quite long-necked quadrupeds (four-legged), often with spatulate (spatula-shaped: broad at
19740-892: Was recognized early in the study of these animals, and, in fact, at least one sauropod specimen found in the 19th century ( Ornithopsis ) was originally misidentified as a pterosaur (a flying reptile) because of this. Some sauropods had armor . There were genera with small clubs on their tails, a prominent example being Shunosaurus , and several titanosaurs , such as Saltasaurus and Ampelosaurus , had small bony osteoderms covering portions of their bodies. A study by Michael D'Emic and his colleagues from Stony Brook University found that sauropods evolved high tooth replacement rates to keep up with their large appetites. The study suggested that Nigersaurus , for example, replaced each tooth every 14 days, Camarasaurus replaced each tooth every 62 days, and Diplodocus replaced each tooth once every 35 days. The scientists found qualities of
19881-442: Was the longest sauropod known from reasonably complete remains, but others, like the old record holder, Diplodocus , were also extremely long. The holotype (and now lost) vertebra of Amphicoelias fragillimus (now Maraapunisaurus ) may have come from an animal 58 metres (190 ft) long; its vertebral column would have been substantially longer than that of the blue whale. However, research published in 2015 speculated that
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