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122-573: Sauropoda indet. Titanosauriformes ? indet. This article about a specific stratigraphic formation in South America is a stub . You can help Misplaced Pages by expanding it . 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

244-409: A cell wall . Newly dead animals may be covered by an exoskeleton . Fragmentation processes, which break through these protective layers, accelerate the rate of microbial decomposition. Animals fragment detritus as they hunt for food, as does passage through the gut. Freeze-thaw cycles and cycles of wetting and drying also fragment dead material. The chemical alteration of the dead organic matter

366-495: A food chain . Real systems are much more complex than this—organisms will generally feed on more than one form of food, and may feed at more than one trophic level. Carnivores may capture some prey that is part of a plant-based trophic system and others that are part of a detritus-based trophic system (a bird that feeds both on herbivorous grasshoppers and earthworms, which consume detritus). Real systems, with all these complexities, form food webs rather than food chains which present

488-605: A habitat . Ecosystem ecology is the "study of the interactions between organisms and their environment as an integrated system". The size of ecosystems can range up to ten orders of magnitude , from the surface layers of rocks to the surface of the planet. The Hubbard Brook Ecosystem Study started in 1963 to study the White Mountains in New Hampshire . It was the first successful attempt to study an entire watershed as an ecosystem. The study used stream chemistry as

610-495: 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

732-420: 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

854-609: A central role over a wide range, for example, in the slow development of soil from bare rock and the faster recovery of a community from disturbance . Disturbance also plays an important role in ecological processes. F. Stuart Chapin and coauthors define disturbance as "a relatively discrete event in time that removes plant biomass". This can range from herbivore outbreaks, treefalls, fires, hurricanes, floods, glacial advances , to volcanic eruptions . Such disturbances can cause large changes in plant, animal and microbe populations, as well as soil organic matter content. Disturbance

976-521: 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

1098-507: A critical role in global nutrient cycling and ecosystem function. Phosphorus enters ecosystems through weathering . As ecosystems age this supply diminishes, making phosphorus-limitation more common in older landscapes (especially in the tropics). Calcium and sulfur are also produced by weathering, but acid deposition is an important source of sulfur in many ecosystems. Although magnesium and manganese are produced by weathering, exchanges between soil organic matter and living cells account for

1220-517: A faster recovery. More severe and more frequent disturbance result in longer recovery times. From one year to another, ecosystems experience variation in their biotic and abiotic environments. A drought , a colder than usual winter, and a pest outbreak all are short-term variability in environmental conditions. Animal populations vary from year to year, building up during resource-rich periods and crashing as they overshoot their food supply. Longer-term changes also shape ecosystem processes. For example,

1342-454: A form that can be readily used by plants and microbes. Ecosystems provide a variety of goods and services upon which people depend, and may be part of. Ecosystem goods include the "tangible, material products" of ecosystem processes such as water, food, fuel, construction material, and medicinal plants . Ecosystem services , on the other hand, are generally "improvements in the condition or location of things of value". These include things like

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1464-427: A function-based typology has been proposed to leverage the strengths of these different approaches into a unified system. Human activities are important in almost all ecosystems. Although humans exist and operate within ecosystems, their cumulative effects are large enough to influence external factors like climate. Ecosystems provide a variety of goods and services upon which people depend. Ecosystem goods include

1586-698: A general level, for example, tropical forests , temperate grasslands , and arctic tundra . There can be any degree of subcategories among ecosystem types that comprise a biome, e.g., needle-leafed boreal forests or wet tropical forests. Although ecosystems are most commonly categorized by their structure and geography, there are also other ways to categorize and classify ecosystems such as by their level of human impact (see anthropogenic biome ), or by their integration with social processes or technological processes or their novelty (e.g. novel ecosystem ). Each of these taxonomies of ecosystems tends to emphasize different structural or functional properties. None of these

1708-402: 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

1830-422: 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"

1952-665: A means of monitoring ecosystem properties, and developed a detailed biogeochemical model of the ecosystem. Long-term research at the site led to the discovery of acid rain in North America in 1972. Researchers documented the depletion of soil cations (especially calcium) over the next several decades. Ecosystems can be studied through a variety of approaches—theoretical studies, studies monitoring specific ecosystems over long periods of time, those that look at differences between ecosystems to elucidate how they work and direct manipulative experimentation. Studies can be carried out at

2074-528: A more important role in moving nutrients around. This can be especially important as the soil thaws in the spring, creating a pulse of nutrients that become available. Decomposition rates are low under very wet or very dry conditions. Decomposition rates are highest in wet, moist conditions with adequate levels of oxygen. Wet soils tend to become deficient in oxygen (this is especially true in wetlands ), which slows microbial growth. In dry soils, decomposition slows as well, but bacteria continue to grow (albeit at

2196-406: A number of common, non random properties in the topology of their network. The carbon and nutrients in dead organic matter are broken down by a group of processes known as decomposition. This releases nutrients that can then be re-used for plant and microbial production and returns carbon dioxide to the atmosphere (or water) where it can be used for photosynthesis. In the absence of decomposition,

2318-513: 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

2440-484: 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

2562-495: 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

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2684-421: A process known as denitrification . Mycorrhizal fungi which are symbiotic with plant roots, use carbohydrates supplied by the plants and in return transfer phosphorus and nitrogen compounds back to the plant roots. This is an important pathway of organic nitrogen transfer from dead organic matter to plants. This mechanism may contribute to more than 70 Tg of annually assimilated plant nitrogen, thereby playing

2806-483: 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

2928-696: A significant portion of ecosystem fluxes. Potassium is primarily cycled between living cells and soil organic matter. Biodiversity plays an important role in ecosystem functioning. Ecosystem processes are driven by the species in an ecosystem, the nature of the individual species, and the relative abundance of organisms among these species. Ecosystem processes are the net effect of the actions of individual organisms as they interact with their environment. Ecological theory suggests that in order to coexist, species must have some level of limiting similarity —they must be different from one another in some fundamental way, otherwise, one species would competitively exclude

3050-408: A slower rate) even after soils become too dry to support plant growth. Ecosystems are dynamic entities. They are subject to periodic disturbances and are always in the process of recovering from past disturbances. When a perturbation occurs, an ecosystem responds by moving away from its initial state. The tendency of an ecosystem to remain close to its equilibrium state, despite that disturbance,

3172-464: A small effect on ecosystem function. Ecologically distinct species, on the other hand, have a much larger effect. Similarly, dominant species have a large effect on ecosystem function, while rare species tend to have a small effect. Keystone species tend to have an effect on ecosystem function that is disproportionate to their abundance in an ecosystem. An ecosystem engineer is any organism that creates, significantly modifies, maintains or destroys

3294-404: 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

3416-455: 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

3538-526: A system to absorb disturbance and reorganize while undergoing change so as to retain essentially the same function, structure, identity, and feedbacks is termed its ecological resilience . Ecosystems can be studied through a variety of approaches—theoretical studies, studies monitoring specific ecosystems over long periods of time, those that look at differences between ecosystems to elucidate how they work and direct manipulative experimentation. Biomes are general classes or categories of ecosystems. However, there

3660-522: A variety of scales, ranging from whole-ecosystem studies to studying microcosms or mesocosms (simplified representations of ecosystems). American ecologist Stephen R. Carpenter has argued that microcosm experiments can be "irrelevant and diversionary" if they are not carried out in conjunction with field studies done at the ecosystem scale. In such cases, microcosm experiments may fail to accurately predict ecosystem-level dynamics. Biomes are general classes or categories of ecosystems. However, there

3782-414: 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

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3904-429: 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,

4026-454: Is an international synthesis by over 1000 of the world's leading biological scientists that analyzes the state of the Earth's ecosystems and provides summaries and guidelines for decision-makers. The report identified four major categories of ecosystem services: provisioning, regulating, cultural and supporting services. It concludes that human activity is having a significant and escalating impact on

4148-442: Is consumed by animals while still alive and enters the plant-based trophic system. After plants and animals die, the organic matter contained in them enters the detritus-based trophic system. Ecosystem respiration is the sum of respiration by all living organisms (plants, animals, and decomposers) in the ecosystem. Net ecosystem production is the difference between gross primary production (GPP) and ecosystem respiration. In

4270-423: Is controlled by internal factors. Therefore, internal factors not only control ecosystem processes but are also controlled by them. Ecosystems are dynamic entities—they are subject to periodic disturbances and are always in the process of recovering from some past disturbance. The tendency of an ecosystem to remain close to its equilibrium state, despite that disturbance, is termed its resistance . The capacity of

4392-453: 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

4514-835: 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

4636-569: Is followed by succession, a "directional change in ecosystem structure and functioning resulting from biotically driven changes in resource supply." The frequency and severity of disturbance determine the way it affects ecosystem function. A major disturbance like a volcanic eruption or glacial advance and retreat leave behind soils that lack plants, animals or organic matter. Ecosystems that experience such disturbances undergo primary succession . A less severe disturbance like forest fires, hurricanes or cultivation result in secondary succession and

4758-554: Is governed by three sets of factors—the physical environment (temperature, moisture, and soil properties), the quantity and quality of the dead material available to decomposers, and the nature of the microbial community itself. Temperature controls the rate of microbial respiration; the higher the temperature, the faster the microbial decomposition occurs. Temperature also affects soil moisture, which affects decomposition. Freeze-thaw cycles also affect decomposition—freezing temperatures kill soil microorganisms, which allows leaching to play

4880-405: Is no clear distinction between biomes and ecosystems. Biomes are always defined at a very general level. Ecosystems can be described at levels that range from very general (in which case the names are sometimes the same as those of biomes) to very specific, such as "wet coastal needle-leafed forests". Biomes vary due to global variations in climate . Biomes are often defined by their structure: at

5002-516: Is no clear distinction between biomes and ecosystems. Ecosystem classifications are specific kinds of ecological classifications that consider all four elements of the definition of ecosystems : a biotic component, an abiotic complex, the interactions between and within them, and the physical space they occupy. Biotic factors of the ecosystem are living things; such as plants, animals, and bacteria, while abiotic are non-living components; such as water, soil and atmosphere. Plants allow energy to enter

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5124-531: Is primarily achieved through bacterial and fungal action. Fungal hyphae produce enzymes that can break through the tough outer structures surrounding dead plant material. They also produce enzymes that break down lignin , which allows them access to both cell contents and the nitrogen in the lignin. Fungi can transfer carbon and nitrogen through their hyphal networks and thus, unlike bacteria, are not dependent solely on locally available resources. Decomposition rates vary among ecosystems. The rate of decomposition

5246-626: 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,

5368-485: Is termed its resistance . The capacity of a system to absorb disturbance and reorganize while undergoing change so as to retain essentially the same function, structure, identity, and feedbacks is termed its ecological resilience . Resilience thinking also includes humanity as an integral part of the biosphere where we are dependent on ecosystem services for our survival and must build and maintain their natural capacities to withstand shocks and disturbances. Time plays

5490-422: Is the "best" classification. Ecosystem classifications are specific kinds of ecological classifications that consider all four elements of the definition of ecosystems : a biotic component, an abiotic complex, the interactions between and within them, and the physical space they occupy. Different approaches to ecological classifications have been developed in terrestrial, freshwater and marine disciplines, and

5612-421: 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

5734-484: 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

5856-711: 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

5978-473: 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,

6100-430: 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

6222-548: 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

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6344-555: The resource inputs are generally controlled by external processes like climate and parent material, the availability of these resources within the ecosystem is controlled by internal factors like decomposition, root competition or shading. Other factors like disturbance, succession or the types of species present are also internal factors. Primary production is the production of organic matter from inorganic carbon sources. This mainly occurs through photosynthesis . The energy incorporated through this process supports life on earth, while

6466-497: 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,

6588-435: The "tangible, material products" of ecosystem processes such as water, food, fuel, construction material, and medicinal plants . They also include less tangible items like tourism and recreation, and genes from wild plants and animals that can be used to improve domestic species. Ecosystem services , on the other hand, are generally "improvements in the condition or location of things of value". These include things like

6710-458: 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

6832-432: 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

6954-459: 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

7076-481: The absence of disturbance, net ecosystem production is equivalent to the net carbon accumulation in the ecosystem. Energy can also be released from an ecosystem through disturbances such as wildfire or transferred to other ecosystems (e.g., from a forest to a stream to a lake) by erosion . In aquatic systems , the proportion of plant biomass that gets consumed by herbivores is much higher than in terrestrial systems. In trophic systems, photosynthetic organisms are

7198-550: 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

7320-402: The amount of energy available to the ecosystem. Parent material determines the nature of the soil in an ecosystem, and influences the supply of mineral nutrients. Topography also controls ecosystem processes by affecting things like microclimate , soil development and the movement of water through a system. For example, ecosystems can be quite different if situated in a small depression on

7442-504: The amount of light available, the amount of leaf area a plant has to capture light (shading by other plants is a major limitation of photosynthesis), the rate at which carbon dioxide can be supplied to the chloroplasts to support photosynthesis, the availability of water, and the availability of suitable temperatures for carrying out photosynthesis. Energy and carbon enter ecosystems through photosynthesis, are incorporated into living tissue, transferred to other organisms that feed on

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7564-418: 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

7686-408: The carbon makes up much of the organic matter in living and dead biomass, soil carbon and fossil fuels . It also drives the carbon cycle , which influences global climate via the greenhouse effect . Through the process of photosynthesis, plants capture energy from light and use it to combine carbon dioxide and water to produce carbohydrates and oxygen . The photosynthesis carried out by all

7808-432: The combustion of fossil fuels, ammonia gas which evaporates from agricultural fields which have had fertilizers applied to them, and dust. Anthropogenic nitrogen inputs account for about 80% of all nitrogen fluxes in ecosystems. When plant tissues are shed or are eaten, the nitrogen in those tissues becomes available to animals and microbes. Microbial decomposition releases nitrogen compounds from dead organic matter in

7930-418: The concept to draw attention to the importance of transfers of materials between organisms and their environment. He later refined the term, describing it as "The whole system, ... including not only the organism-complex, but also the whole complex of physical factors forming what we call the environment". Tansley regarded ecosystems not simply as natural units, but as "mental isolates". Tansley later defined

8052-403: The dead organic matter would accumulate in an ecosystem, and nutrients and atmospheric carbon dioxide would be depleted. Decomposition processes can be separated into three categories— leaching , fragmentation and chemical alteration of dead material. As water moves through dead organic matter, it dissolves and carries with it the water-soluble components. These are then taken up by organisms in

8174-523: 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

8296-643: The ecosystem or to gradual disruption of biotic processes and degradation of abiotic conditions of the ecosystem. Once the original ecosystem has lost its defining features, it is considered "collapsed ". Ecosystem restoration can contribute to achieving the Sustainable Development Goals . An ecosystem (or ecological system) consists of all the organisms and the abiotic pools (or physical environment) with which they interact. The biotic and abiotic components are linked together through nutrient cycles and energy flows. "Ecosystem processes" are

8418-405: 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

8540-423: 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

8662-488: 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

8784-421: The flow of energy through a lake was the primary driver of the ecosystem. Hutchinson's students, brothers Howard T. Odum and Eugene P. Odum , further developed a "systems approach" to the study of ecosystems. This allowed them to study the flow of energy and material through ecological systems. Ecosystems are controlled by both external and internal factors. External factors, also called state factors, control

8906-593: 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

9028-478: 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

9150-418: 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

9272-452: The forests of eastern North America still show legacies of cultivation which ceased in 1850 when large areas were reverted to forests. Another example is the methane production in eastern Siberian lakes that is controlled by organic matter which accumulated during the Pleistocene . Ecosystems continually exchange energy and carbon with the wider environment . Mineral nutrients, on

9394-401: 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

9516-514: The growth of sauropods, their theropod predators grew also, as shown by an Allosaurus -sized coelophysoid from Germany . Ecosystem An ecosystem (or ecological system ) is a system that environments and their organisms form through their interaction. The biotic and abiotic components are linked together through nutrient cycles and energy flows. Ecosystems are controlled by external and internal factors . External factors such as climate , parent material which forms

9638-447: 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

9760-483: 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

9882-691: The landscape, versus one present on an adjacent steep hillside. Other external factors that play an important role in ecosystem functioning include time and potential biota , the organisms that are present in a region and could potentially occupy a particular site. Ecosystems in similar environments that are located in different parts of the world can end up doing things very differently simply because they have different pools of species present. The introduction of non-native species can cause substantial shifts in ecosystem function. Unlike external factors, internal factors in ecosystems not only control ecosystem processes but are also controlled by them. While

10004-418: 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

10126-584: 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

10248-423: The living and dead plant matter, and eventually released through respiration. The carbon and energy incorporated into plant tissues (net primary production) is either consumed by animals while the plant is alive, or it remains uneaten when the plant tissue dies and becomes detritus . In terrestrial ecosystems , the vast majority of the net primary production ends up being broken down by decomposers . The remainder

10370-462: 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

10492-471: The maintenance of hydrological cycles , cleaning air and water, the maintenance of oxygen in the atmosphere, crop pollination and even things like beauty, inspiration and opportunities for research. Many ecosystems become degraded through human impacts, such as soil loss , air and water pollution , habitat fragmentation , water diversion , fire suppression , and introduced species and invasive species . These threats can lead to abrupt transformation of

10614-408: The maintenance of hydrological cycles, cleaning air and water, the maintenance of oxygen in the atmosphere, crop pollination and even things like beauty, inspiration and opportunities for research. While material from the ecosystem had traditionally been recognized as being the basis for things of economic value, ecosystem services tend to be taken for granted. The Millennium Ecosystem Assessment

10736-590: 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

10858-519: 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

10980-641: 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

11102-431: 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

11224-537: The other hand, are mostly cycled back and forth between plants, animals, microbes and the soil. Most nitrogen enters ecosystems through biological nitrogen fixation , is deposited through precipitation, dust, gases or is applied as fertilizer . Most terrestrial ecosystems are nitrogen-limited in the short term making nitrogen cycling an important control on ecosystem production. Over the long term, phosphorus availability can also be critical. Macronutrients which are required by all plants in large quantities include

11346-509: The other. Despite this, the cumulative effect of additional species in an ecosystem is not linear: additional species may enhance nitrogen retention, for example. However, beyond some level of species richness, additional species may have little additive effect unless they differ substantially from species already present. This is the case for example for exotic species . The addition (or loss) of species that are ecologically similar to those already present in an ecosystem tends to only have

11468-403: The overall structure of an ecosystem and the way things work within it, but are not themselves influenced by the ecosystem. On broad geographic scales, climate is the factor that "most strongly determines ecosystem processes and structure". Climate determines the biome in which the ecosystem is embedded. Rainfall patterns and seasonal temperatures influence photosynthesis and thereby determine

11590-405: The plants in an ecosystem is called the gross primary production (GPP). About half of the gross GPP is respired by plants in order to provide the energy that supports their growth and maintenance. The remainder, that portion of GPP that is not used up by respiration, is known as the net primary production (NPP). Total photosynthesis is limited by a range of environmental factors. These include

11712-584: 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

11834-532: 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

11956-585: The primary nutrients (which are most limiting as they are used in largest amounts): Nitrogen, phosphorus, potassium. Secondary major nutrients (less often limiting) include: Calcium, magnesium, sulfur. Micronutrients required by all plants in small quantities include boron, chloride, copper, iron, manganese, molybdenum, zinc. Finally, there are also beneficial nutrients which may be required by certain plants or by plants under specific environmental conditions: aluminum, cobalt, iodine, nickel, selenium, silicon, sodium, vanadium. Until modern times, nitrogen fixation

12078-413: The primary producers. The organisms that consume their tissues are called primary consumers or secondary producers — herbivores . Organisms which feed on microbes ( bacteria and fungi ) are termed microbivores . Animals that feed on primary consumers— carnivores —are secondary consumers. Each of these constitutes a trophic level. The sequence of consumption—from plant to herbivore, to carnivore—forms

12200-642: 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

12322-422: 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

12444-598: 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

12566-401: 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

12688-451: 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

12810-409: 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

12932-477: 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,

13054-537: 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

13176-409: The soil and topography , control the overall structure of an ecosystem but are not themselves influenced by the ecosystem. Internal factors are controlled, for example, by decomposition , root competition, shading, disturbance, succession, and the types of species present. While the resource inputs are generally controlled by external processes, the availability of these resources within the ecosystem

13298-611: The soil, react with mineral soil, or are transported beyond the confines of the ecosystem (and are considered lost to it). Newly shed leaves and newly dead animals have high concentrations of water-soluble components and include sugars , amino acids and mineral nutrients. Leaching is more important in wet environments and less important in dry ones. Fragmentation processes break organic material into smaller pieces, exposing new surfaces for colonization by microbes. Freshly shed leaf litter may be inaccessible due to an outer layer of cuticle or bark , and cell contents are protected by

13420-511: The soil, where plants, fungi, and bacteria compete for it. Some soil bacteria use organic nitrogen-containing compounds as a source of carbon, and release ammonium ions into the soil. This process is known as nitrogen mineralization . Others convert ammonium to nitrite and nitrate ions, a process known as nitrification . Nitric oxide and nitrous oxide are also produced during nitrification. Under nitrogen-rich and oxygen-poor conditions, nitrates and nitrites are converted to nitrogen gas ,

13542-483: The spatial extent of ecosystems using the term " ecotope ". G. Evelyn Hutchinson , a limnologist who was a contemporary of Tansley's, combined Charles Elton 's ideas about trophic ecology with those of Russian geochemist Vladimir Vernadsky . As a result, he suggested that mineral nutrient availability in a lake limited algal production . This would, in turn, limit the abundance of animals that feed on algae. Raymond Lindeman took these ideas further to suggest that

13664-467: 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

13786-454: The system through photosynthesis , building up plant tissue. Animals play an important role in the movement of matter and energy through the system, by feeding on plants and on one another. They also influence the quantity of plant and microbial biomass present. By breaking down dead organic matter , decomposers release carbon back to the atmosphere and facilitate nutrient cycling by converting nutrients stored in dead biomass back to

13908-434: 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

14030-413: 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

14152-421: The transfers of energy and materials from one pool to another. Ecosystem processes are known to "take place at a wide range of scales". Therefore, the correct scale of study depends on the question asked. The term "ecosystem" was first used in 1935 in a publication by British ecologist Arthur Tansley . The term was coined by Arthur Roy Clapham , who came up with the word at Tansley's request. Tansley devised

14274-415: 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

14396-433: 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

14518-603: 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

14640-892: 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

14762-442: 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

14884-679: Was the major source of nitrogen for ecosystems. Nitrogen-fixing bacteria either live symbiotically with plants or live freely in the soil. The energetic cost is high for plants that support nitrogen-fixing symbionts—as much as 25% of gross primary production when measured in controlled conditions. Many members of the legume plant family support nitrogen-fixing symbionts. Some cyanobacteria are also capable of nitrogen fixation. These are phototrophs , which carry out photosynthesis. Like other nitrogen-fixing bacteria, they can either be free-living or have symbiotic relationships with plants. Other sources of nitrogen include acid deposition produced through

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