Apatosaurus | Scholastic Apatosaurus Grades 3–5 Apatosaurus was one of a number of giant, plant-eating dinosaurs that roamed western North America during the Late Jurassic Period, more than 140 million years ago. The animal probably will remain better known for some time under the name Brontosaurus, because this name has been used in many books and films about dinosaurs. Paleontologists use the name Apatosaurus, however, because the first fossil fragment of the animal was so labeled, and by scientific convention the first name given is the one accepted. Apatosaurus and other giants such as Brachiosaurus, Diplodocus, and Camarasaurus constitute the suborder Sauropoda. These five-toed, long-necked dinosaurs were the dominant herbivores of their time. Their fossils occur in abundance in rock formations in Utah, Colorado, and Wyoming. Apatosaurus had an enormous, barrellike body supported by thick, heavy legs. Its tail and neck were long and stout. More than 25 m (82 ft) in total length, it weighed 18-32 metric tons (20-35 U.S. tons).

The skull was elongated and had short but pointed teeth. Apatosaurus skeletons are usually headless when they are found, however, because of fragile skull and neck connections. When the American paleontologist O. C. Marsh uncovered the first such skeleton, in 1879, he paired it with a wrong skull found nearby — that of the dinosaur now known as Camarasaurus. As a result, Apatosaurus was depicted as having a snub-nosed head with peglike teeth until the late 1970s, when the error was corrected. Traditionally, paleontologists have regarded Apatosaurus as a semiaquatic animal, feeding and wallowing in lakes, swamps, and rivers. This idea was based on the belief that the animal's enormous weight was too great for the legs to bear and that it therefore needed to live in water to support its weight. Using this line of reasoning, some scientists suggested that the animal's long neck permitted it to breathe while at depths of 6-8 m (20-25 ft). This theory is flawed, however, because water pressures at depths of only a few meters would have been too great to permit the animal to breathe.

More recently it has been suggested that all of the sauropods lived on land, using their long necks to reach and browse on treetop foliage. John H. Ostrom Bibliography: Alexander, R. McNeill, The Dynamics of Dinosaurs and Other Extinct Giants (1989); Glut, D. F., The Complete Dinosaur Dictionary (1992); Lambert, David, The Dinosaur Data Book (1990); Weishampel, David, et al., eds., The Dinosauria (1990). × Apatosaurus: Facts About the 'Deceptive Lizard' Apatosaurus: Facts About the 'Deceptive Lizard' By Joseph Castro, Live Science Contributor | March 16, 2016 01:17pm ET MORE Credit: Linda Bucklin | Shutterstock While some people outside the scientific community still refer to Apatosaurus as Brontosaurus, the name Brontosaurus was actually the result of a fossil mix-up. American paleontologist Othniel C.

Marsh named one of his fossil discoveries — an incomplete set of the remains of a juvenile dinosaur — Apatosaurus ajax in 1877. Two years later, in 1879, he discovered another sauropod (dinosaurs best known for their incredibly long necks) specimen that was larger and more complete. Marsh believed the new find represented an entirely different genus of dinosaur, and decided to name it Brontosaurus excelsus. In 1903, paleontologist Elmer Riggs re-examined Marsh's fossils and concluded that they were similar enough to belong to the same genus (most paleontologists today support his conclusions). According to naming conventions, the older name takes precedence, meaning that Brontosaurus excelsus should actually be Apatosaurus excelsus. However, Riggs published his examination in a relatively obscure journal, so his findings were largely unknown to people at the time. Additionally, by this time, the name Brontosaurus had gained a lot of public exposure by various non-scientific places, such as the Sinclair oil company, which used the animal as its logo, according to paleontologist Michael Taylor .

Today, Brontosaurus is still a well-known moniker and remained in popular use until a few decades ago. The Flintstones' pet dinosaur, Dino, was described as a Brontosaurus. Fred Flintstone was also known to eat Bronto-burgers. The U.S. Postal Service even used the name in 1989 when it issued a series of dinosaur stamps, contending that the name was more familiar to the general public than Apatosaurus, according to the New York Times . And still, the naming controversy continues . A 2015 study suggested that there are enough differences between two Apatosaurus specimens that one of them should be in a different genus and reclassified Brontosaurus. Artwork by Scott Hartman reveals the bone structure of Apatosaurus. Credit: © Scott Hartman / All rights reserved Anatomy of a giant Apatosaurus was an herbivorous sauropod dinosaur that lived from about 155.7 to 150.8 million years ago, during the Kimmeridgian and early Tithonian ages of the Jurassic Period.

The term Apatosaurus comes from the Greek words apate/apatelos, meaning "deceptive," and sauro, meaning "lizard." Marsh gave it this name because some of its bones resembled those of some mosasaurs, a type of large aquatic reptile. It's believed to be one of the biggest land animals to have roamed the Earth. Fossils of A. louisae (the largest known Apatosaurus species) suggest the dinosaur reached 68.9 to 74.8 feet (21 to 22.8 meters) in length. In the past, Apatosaurus was estimated to weigh up to 39 tons (35 metric tons, or 35,000 kilograms), but modern modeling techniques puts its average weight closer to 19.8 tons (18 metric tons), according to a 2009 study in the Journal of Zoology. Like other sauropods, the vertebrae were made up of paired spines, producing a very wide and thick neck. But its neck was not as heavy as it might have been, thanks to a system of air sacs that kept it relatively light for its size.

The neck posture and neck flexibility of Apatosaurus and other sauropods is highly debated. Computer models in the 1990s suggested that Apatosaurus had little neck flexibility and probably held its head horizontally (it wouldn’t have been able to eat from the tops of trees and then bend its head all the way down to the ground to drink water). But based on comparisons with animals alive today, Apatosaurus may have held its head high with a swan-like S-curve to its flexible neck, a 2009 study in the journal Acta Palaeontologica Polonica argued. However, a 2013 study in the journal PLOS ONE looked at the neck flexibility of ostriches (the closest long-neck sauropod relative), and concluded that previous neck-flexibility models, which don't take into account the effect of soft tissues, cannot truly estimate the flexibility of sauropod necks — what this means for the actual posture and flexibility of Apatosaurus necks is unclear. Apatosaurus had legs that were sturdier and not as elongated as other sauropods, such as Brachiosaurus , and its hind limbs were larger than its forelimbs.

Like most sauropods, Apatosaurus had only a single large claw on each forelimb, with the first three toes on the hind limb possessing claws. Its tail was long and unusually slim, resembling a bullwhip. A computer model detailed in a 1997 Discover magazine article found that the crack of the tail tip would have produced a "cannonlike boom" heard for miles. However, the slender tip of Apatosaurus' tail would probably be unable to hurt any predators, negating its use as a weapon. Apatosaurus, like its close relative Supersaurus, had unusually tall spines on its vertebrae, which make up more than half the height of the individual bones. The vertebral spines rapidly decrease in height the farther they are from the hips, giving the tail its slender shape. Apatosaurus had a skull that was rather small for its body size. It contained chisel-like teeth, suited to an herbivorous diet. What did Apatosaurus eat? It's believed that Apatosaurus primarily fed on low-lying plants, but its long neck may have enabled this sauropod to eat soft leaves on higher trees, if its neck was flexible enough.

Apatosaurus likely swallowed large chunks of plants without chewing and ingested stones to help with digestion. Like other large sauropods, Apatosaurus probably had to eat up to 400 kilograms (880 pounds) of food every day to survive, according to a 2008 study in the Proceeding of the Royal Society B. In the early 2000s, some scientists suggested Apatosaurus and other large sauropods got to be so huge because of their food supply. That is, their food was so low in nitrogen — which is necessary for protein formation and energy — that they had to eat a lot of it to survive, increasing their body size. Subsequent research, which analyzed the total energy in modern plants, discarded this idea. "But the idea isn't based on energy, it's based on carbon-to-nitrogen ratios," Wilkinson told LiveScience. In a 2012 study in the journal Functional Ecology, Wilkinson and his colleagues took another look at the theory, and concluded that it shouldn't be written off just yet . "Our key point is that the idea is still a contender.

" However, some research suggests other factors may have been more important in driving up sauropods' body sizes, such as swallowing large amounts of food without chewing. Learn about the Jurassic-era plant eating dinosaur Apatosaurus. Credit: Ross Toro, Livescience contributor Dinosaur farts Like the big herbivores of today, Apatosaurus probably relied on gut microbes to help them digest plant matter, resulting in the production of the greenhouse gas methane. In a 2012 study in the journal Current Biology, researchers calculated that Apatosaurus and other sauropods produced about 520 million tons of methane per year , which is not so different from the amount of methane currently produced by both natural and manmade sources. "They produced enough methane to have a minor but measurable effect on the global climate ," said study lead researcher David Wilkinson, a biologist at Liverpool John Moores University in the United Kingdom. "In theory, they could have produced enough methane to play a role in sustaining the warm climate of the Mesozoic era." Fossil finds Apatosaurus fossils have been unearthed in Nine Mile Quarry and Bone Cabin Quarry in Wyoming as well as in areas of Colorado, Oklahoma and Utah.

Apatosaurus louisae was named by William Holland in 1915 in honor of Louise Carnegie , wife of Andrew Carnegie who funded field research to find complete dinosaur skeletons in the American West. Apatosaurus louisae is known from one nearly complete skeleton, which was found in Utah. In 2008, footprints of a juvenile Apatosaurus were found in Quarry Five in Morrison, Colo. Discovered by Matthew Mossbrucker, these footprints indicated that juveniles could run on their hind legs , according to Smithsonian Magazine. In 2013, Mossbrucker identified the first A. ajax snout ever discovered , which may help paleontologists better understand how the dinosaur is related to other sauropods. Additional reporting by Kim Ann Zimmermann, Live Science Contributor Related pages Apatosaurus | Animal of the world Wiki | Fandom powered by Wikia Animal of the world Wiki Robert T. Bakker made A. yahnahpin the type species of a new genus, Eobrontosaurus in 1998, so it is now correctly Eobrontosaurus yahnahpin. Filla, James and Redman named it in 1994.

One partial skeleton has been found in Wyoming Fast Facts Edit Type: Sauropod Dinosaur Diet: Herbivore Size: About 4.5 meters (15 feet) tall at the hips, with a length of up to 25m (80 feet) and a mass up to 35 metric tones (40 tons). Protection status: Extinct Apatosaurus, formerly known as Brontosaurus (erroneously named Brontosaurus by Othniel Charles Marsh after he incorrectly placed the head of a Camarasaurus on the body of an Apatosaurus), is a genus of sauropod dinosaurs that lived about 140 million years ago, during the Jurassic period. They were some of the major land animals that ever existed, about 4.5 meters (15 feet) tall at the hips, with a length of up to 25m (80 feet) and a mass up to 35 metric tones (40 tons). However, the Argentinosaurus was even larger. The cervical vertebra and the bones in the legs were larger and heavier than that of Diplodocus, but they both had the long neck and tail.

Apatosaurus skeleton which was found at the American Museum of Natural History. The skull was first recognized in 1975, a century after it got its name. The Apatosaurus had a claw on its hand, but only the thumb. Scientists have a theory about the tail being lifted perhaps a meter above the ground. It would prevent the dinosaur from stomping on it, and put the tail out of arrive at of predators. Early on, it was believed that Apatosaurus was too massive to support its own weight on dry land, so it was theorized that the sauropod must have lived partly submerged in water, perhaps in a swamp. Recent conclusion does not support this. Fossilized footprints indicate that it probably lived in herds. To aid in dispensation food, Apatosaurus may have swallowed gizzard stones (gastroliths) the same way many birds do today — its jaws alone were not sufficient to chew tough plant fibers. The Apatosaurs perhaps lumbered along in flocks on riverbanks with trees, eating off the top leaves.

Scientists believe that these sauropods could not raise their neck to an angle of 90 degrees, as doing so would sluggish blood flow to the brain excessively; blood starting at the body proper would take two or more minutes to reach the brain. Furthermore, studies of the arrangement of the neck vertebrae have revealed that the neck was not as flexible as previously thought. No one knows how Apatosaurs ate enough food to gratify their enormous bodies. They probably ate constantly, pausing only to cool off, drink or to remove parasites. They must have slept standing upright. If attacked by a predator, it could preserve itself by swinging its tail from side to side, or stomp at the meat-eater. Because of the Apatosaurs’ slow velocity, they lived in herds, and they could "call" on each other, if one needed help. Classification and history of Apatosaurus Dinosaurs In 1877, Othniel Charles Marsh available notes on his discovery of the Apatosaurus, and then in 1879 described one more, more complete dinosaur — the Brontosaurus.

In 1903, it was discovered that the apatosaur was in fact a juvenile brontosaur, and the name Apatosaurus, having been published first, was deemed to have priority as the bureaucrat name; Brontosaurus was relegated to being a synonym. The name was not formally removed from the records of paleontology until 1974. Fossils of this animal have been establish in Nine Mile Quarry and Bone Cabin Quarry in Wyoming, and at sites in Colorado, Oklahoma, Utah, USA. Species A. Ajax is the type species of the genera, and was named by the paleontologist Othniel Charles Marsh in 1877 after Ajax, the hero from Greek mythology. It is the holotype for the genera, and two partial skeletons have been found including part of a skull. A. Excelsus (originally Brontosaurus) was named by Marsh in 1879. It is known from six partial skeletons, including part of a skull, which have been establish in the United States, in Oklahoma, Utah, and Wyoming. A. louisae was named by William Holland, in 1915.

It is known from one incomplete skeleton, which was found in Colorado, in the United States. Apatosaurus Dinosaur, Facts | information - Apatosaurus Fossils Dinosaurs » A-Z Dinosaurs List » Apatosaurus Dinosaur Apatosaurus Dinosaur Apatosaurus , formerly known as Brontosaurus (erroneously named Brontosaurus by Othniel Charles Marsh after he incorrectly placed the head of a Camarasaurus on the body of an Apatosaurus), is a genus of sauropod dinosaurs that lived about 140 million years ago, during the Jurassic period. They were some of the major land animals that ever existed, about 4.5 meters (15 feet) tall at the hips, with a length of up to 25m (80 feet) and a mass up to 35 metric tones (40 tons). However, the Argentinosaurus was even larger. The cervical vertebra and the bones in the legs were larger and heavier than that of Diplodocus, but they both had the long neck and tail. Apatosaurus skeleton which was found at the American Museum of Natural History .

The skull was first recognized in 1975, a century after it got its name. The Apatosaurus had a claw on its hand, but only the thumb. Scientists have a theory about the tail being lifted perhaps a meter above the ground. It would prevent the dinosaur from stomping on it, and put the tail out of arrive at of predators. Early on, it was believed that Apatosaurus Dinosaurs was too massive to support its own weight on dry land, so it was theorized that the sauropod must have lived partly submerged in water, perhaps in a swamp. Recent conclusion does not support this. Fossilized footprints indicate that it probably lived in herds. To aid in dispensation food, Apatosaurus may have swallowed gizzard stones (gastroliths) the same way many birds do today — its jaws alone were not sufficient to chew tough plant fibers. The Apatosaurs perhaps lumbered along in flocks on riverbanks with trees, eating off the top leaves.

Scientists believe that these sauropods could not raise their neck to an angle of 90 degrees, as doing so would sluggish blood flow to the brain excessively; blood starting at the body proper would take two or more minutes to reach the brain. Furthermore, studies of the arrangement of the neck vertebrae have revealed that the neck was not as flexible as previously thought. No one knows how Apatosaurs ate enough food to gratify their enormous bodies. They probably ate constantly, pausing only to cool off, drink or to remove parasites. They must have slept standing upright. If attacked by a predator, it could preserve itself by swinging its tail from side to side, or stomp at the meat-eater. Because of the Apatosaurs’ slow velocity, they lived in herds, and they could "call" on each other, if one needed help. Classification and history of Apatosaurus Dinosaurs In 1877, Othniel Charles Marsh available notes on his discovery of the Apatosaurus, and then in 1879 described one more, more complete dinosaur — the Brontosaurus.

In 1903, it was discovered that the apatosaur was in fact a juvenile brontosaur, and the name Apatosaurus, having been published first, was deemed to have priority as the bureaucrat name; Brontosaurus was relegated to being a synonym. The name was not formally removed from the records of paleontology until 1974. Fossils of this animal have been establish in Nine Mile Quarry and Bone Cabin Quarry in Wyoming, and at sites in Colorado, Oklahoma, Utah, USA. Species A. Ajax is the type species of the genera, and was named by the paleontologist Othniel Charles Marsh in 1877 after Ajax, the hero from Greek mythology. It is the holotype for the genera, and two partial skeletons have been found including part of a skull. A. Excelsus (originally Brontosaurus) was named by Marsh in 1879. It is known from six partial skeletons, including part of a skull, which have been establish in the United States, in Oklahoma, Utah, and Wyoming. A. louisae was named by William Holland, in 1915.

It is known from one incomplete skeleton, which was found in Colorado, in the United States. Robert T. Bakker made A. yahnahpin the type species of a new genus, Eobrontosaurus in 1998, so it is now correctly Eobrontosaurus yahnahpin. Filla, James and Redman named it in 1994. One partial skeleton has been found in Wyoming Apatosaurus facts: Dinosaur Dinosaur, one of a group of extinct reptiles that lived from about 230 million to about 65 million years ago. The word dinosaur was coined in 1842 by the British anatomist Sir Richard Owen, derived from the Greek words deinos, meaning "marvelous" or "terrible," and sauros, meaning "lizard." For more than 140 million years, dinosaurs reigned as the dominant animals on land. Owen distinguished dinosaurs from other prehistoric reptiles by their upright rather than sprawling legs and by the presence of three or more vertebrae supporting the pelvis, or hipbone.

Dinosaurs are classified into two orders according to differences in pelvic structure: Saurischia, or lizard-hipped dinosaurs, and Ornithischia, or bird-hipped dinosaurs. Dinosaur bones occur in sediments that were deposited during the Mesozoic Era, the so-called era of middle animals, also known as the age of reptiles. This era is divided into three periods: the Triassic (dating from 245 million to 208 million years ago), the Jurassic (208 million to 144 million years ago), and the Cretaceous (144 million to 65 million years ago). Historical references to dinosaur bones may extend as far back as the 5th century BC. Some scholars think that the Greek historian Herodotus was referring to fossilized dinosaur skeletons and eggs when he described griffinslegendary beasts that were part eagle and part lionguarding nests in central Asia. "Dragon bones" mentioned in a 3rd century AD text from China are thought to refer to bones of dinosaurs.

The first dinosaurs studied by paleontologists (scientists who study prehistoric life) were Megalosaurus and Iguanodon, whose partial bones were discovered early in the 19th century in England. The shape of their bones indicates that these animals were large, land-dwelling reptiles. The teeth of Megalosaurus, which are pointed and have serrated edges, indicate that this animal was a flesh eater, while the flattened, grinding surfaces of Iguanodon teeth indicate that it was a plant eater. Megalosaurus lived during the Jurassic Period, and Iguanodon lived during the later Cretaceous Period. Later in the 19th century, paleontologists collected and studied more complete skeletons of related dinosaurs found in New Jersey. From these finds they learned that Megalosaurus and Iguanodon walked on two legs, not four, as had been thought. In the late 19th and early 20th century, as the science of paleontology grew and the search for dinosaur remains was extended around the world, new kinds of dinosaurs were discovered.

At present, about 300 different varieties of dinosaur have been identified from bones found on all of the continents as well as on the islands of Greenland, Madagascar, and New Zealand. Ancestry The ancestors of dinosaurs were crocodilelike creatures called archosaurs. They appeared early in the Triassic Period and diversified into a variety of forms that are popularly known as the thecodont group of reptiles. Many of these creatures resembled later Cretaceous dinosaurs. Some archosaurs gave rise to true crocodiles. Others gave rise to pterosaurs, flying reptiles that possessed slender wings supported by a single sparlike finger. Still other archosaurs adopted a bipedal (two-legged) posture and developed S-shaped necks, and it was certain species of these reptiles that eventually evolved into dinosaurs. The earliest evidence of dinosaurs is about 230 million years old and includes traces of both orders of dinosaursSaurischia and Ornithischia. This evidence suggests that the earliest dinosaurs, thought to have first appeared about 240 million years ago, were about 0.5 m (about 1.6 ft) long and fed on small animals as well as on tender plants.

Eoraptor was a 1 m (3 ft) long early saurischian with a primitive skull. Herrerasaurus, 3 m (10 ft) long and weighing 250 kg (550 lb), was a relatively large flesh-eating saurischian with a primitive pelvis. The ancestors of sauropods, the largest herbivorous dinosaurs, are represented at this early stage by a few moderately large bones of prosauropods. Ornithischians are represented by the isolated bones and teeth of a few tiny dinosaurs. After the middle of the Triassic Period, saurischians slowly increased in size and abundance. Ornithischians began to diversify early in the Jurassic Period. By the middle of the Jurassic Period, most of the basic varieties of dinosaurs had appeared, including forms which far surpassed modern elephants in size. Dinosaurs had evolved into the most abundant large animals on land, and the dinosaurian age had begun. Habitat The earth's environment during the dinosaurian era was far different than it is today. The days were several minutes shorter than they are today because the gravitational pull of the sun and the moon have over time had a braking influence on the earth's rotation.

Radiation from the sun was not as strong as it is today because the sun has been slowly brightening over time. Other changes in the environment may be linked to the atmosphere. Carbon dioxide, a gas that traps heat from the sun in the earth's atmospherethe so-called greenhouse effectwas several times more abundant in the air during the dinosaurian age. As a result, surface temperatures were warmer and no polar ice caps could form. The pattern of continents and oceans was also very different during the age of dinosaurs. At the beginning of the dinosaurian era, the continents were united into a gigantic supercontinent called Pangaea (all lands), and the oceans formed a vast world ocean called Panthalassa (all seas). About 200 million years ago, movements of the earth's crust caused the supercontinent to begin slowly separating into northern and southern continental blocks, which broke apart further into the modern continents by the end of the dinosaurian era. As a result of these movements of the earth's crust (see Plate Tectonics), there was less land in equatorial regions than there is at present.

Deserts, possibly produced by the warm, greenhouse atmosphere, were widespread across equatorial land, and the tropics were not as rich an environment for life forms as they are today. Plants and animals may have flourished instead in the temperate zones north and south of the equator. The most obvious differences between dinosaurian and modern environments are the difference in the types of life forms present. There were fewer than half as many species of plants and animals on land during the Mesozoic Era as there are today. Bushes and trees appear to have provided the most abundant sources of food for dinosaurs, rather than the rich grasslands that feed most animals today. Although flowering plants appeared during the dinosaurian era, few of them bore nuts or fruit. The animals of the period had slower metabolisms and smaller brains, suggesting that the pace of life was relatively languid and the behavior patterns were simple. The more active animalssuch as ants, wasps, birds, and mammalsfirst made their appearance during the dinosaurian era but were not as abundant as they are now. Behavior and Physiology The behavior of dinosaurs was governed by their metabolism and by their central nervous system.

The dinosaurs' metabolismhow they changed their food into energyaffected their activity level. It is unclear whether dinosaurs were purely endothermic (warm-blooded), like modern mammals, or ectothermic (cold-blooded), like modern reptiles. Endotherms regulate their body temperature internally by means of their metabolism, rather than by using the temperature of their surroundings. As a result, they have higher activity levels and higher energy needs than ectotherms. Ectotherms have a slower metabolism and regulate their body temperature by means of their behavior, taking advantage of external temperature variations by sunning themselves to stay warm and resting in the shade to cool down. By determining whether dinosaurs were warm- or cold-blooded, paleontologists could discover whether dinosaurs behaved more like modern mammals or more like modern reptiles. Gradual changes in dinosaur anatomy suggest that the metabolic rates and activity levels of dinosaurs increased as they evolved, and some scientists believe this indicates that dinosaurs became progressively more endothermic. In general, dinosaur body size decreased throughout the latter half of the dinosaurian era, increasing the dinosaurs' need for activity and a higher metabolism to maintain warmth.

Smaller animals have more surface area in proportion to their volume, which causes them to lose more heat as it radiates from their skin. Dinosaurs' tooth batteries (many small teeth packed together) became larger, allowing them to chew their food more efficiently, their breathing passages became separated from their mouth cavity, allowing them to chew and breath at the same time, and their nostrils became larger, making their breathing more efficient. These changes may have helped the dinosaurs digest their food and change it into energy more quickly and efficiently, thereby helping them maintain a higher metabolism. The central nervous system of dinosaurs affected their behavioral flexibilityhow much they could adapt their behavior to deal with changing situations. Scientists believe that the ratio of dinosaurs' brain size to their body weight increased as the animals evolved. As a result, their behavioral flexibility increased from a level comparable to that of modern crocodiles, in the primitive dinosaurs, to a level comparable to that of modern chickens and opossums, in some small Cretaceous dinosaurs. Using fossil records, paleontologists have identified some of the physical characteristics of dinosaurs. Imprints of dinosaur skin show that the skin had a textured surface without hair or feathers.

The eyes of dinosaurs were about twice the diameter of those of modern mammals. In general appearance they looked like giant, but distant, cousins of birds and mammals. The skeleton of one small dinosaur was found preserved in windblown sand. Its head was tucked next to its forelimbs, resembling the posture of a modern bird, and its tail was wrapped around its body, resembling the posture of a cat. Many, if not all, dinosaurs laid eggs, and extensive deposits of whole and fragmented shells have been found in China and India, suggesting that large nesting colonies were common. A very few eggs have been identified from the skeletons of embryos contained within them. In proportion to the body weight of the mother, dinosaurs laid smaller eggs in greater numbers than do birds. Indeed, the largest known dinosaur eggs are 7400 cm3 (450 in3) smaller than the largest known bird eggs, which are 12,700 cm3 (775 in3). Scientists have found what they believe is a typical nest dug into Cretaceous streamside clays in Montana. The nest is a craterlike structure about 2 m (6.6 ft) in diameterabout the diameter of the mother's body.

The large number of bones of small dinosaurs that have been found in nesting colonies indicate that the mortality rate of juveniles was very high. The growth rings preserved in dinosaur bones suggest that primitive dinosaurs grew more slowly than later dinosaurs. Judging from these growth rings, and from body size and longevity trends in modern reptiles, some paleontologists suggest that giant dinosaurs had an average life span of over 100 years. Saurischian Dinosaurs Saurischian dinosaurs were characterized by a primitive pelvis, with a single bone projecting down and back from each side of the hips. This pelvis construction was similar to that of other ancient reptiles but, unlike other reptiles, saurischians had stronger backbones, no claws on their outer front digits, and forelimbs that were usually much shorter than the hind limbs. There were three basic kinds of saurischians: theropods, prosauropods, and sauropods. Theropods Nearly all theropods were bipedal flesh-eaters. Some theropods, such as Tyrannosaurus rex of the late part of the Cretaceous Period, reached lengths of 12 m (39 ft) and weights of 5 metric tons.

In large theropods the huge jaws and teeth were adapted to tearing prey apart. Fossil trackways reveal that these large theropods walked more swiftly than large plant-eating dinosaurs and were more direct and purposeful in their movements. Other theropods, such as Compsognathus, were small and gracefully built, resembling modern running birds such as the roadrunner. Their heads were slender and often beaked, suggesting that these theropods fed on small animals such as lizards and infant dinosaurs. Some of them possessed brains as large as those of modern chickens and opossums. Other theropods, called raptors, bore powerful claws, like those of an eagle, on their hands and feet and used their flexible tails as balancing devices to increase their agility when turning. These animals appear to have hunted in packs. Many paleontologists believe that birds may have arisen from small, primitive theropods that were also ancestors of the raptors. Evidence for this theory has been augmented by the discovery of an Oviraptor nest in the Gobi Desert. The nest contains the fossil bones of an Oviraptor sitting on its brood of about 15 eggs, exhibiting behavior remarkably similar to that of modern birds.

Prosauropod Unlike the primitive theropods, the prosauropods had relatively small skulls and spoon-shaped, rather than blade-shaped, teeth. Their necks were long and slender and, because they were bipedal, the prosauropods could browse easily on the foliage of bushes and trees that were well beyond the reach of other herbivores. A large clawed, hooklike thumb was probably used to grasp limbs while feeding. The feet were broad and also heavily clawed. When prosauropods appeared in the fossil record along with the earliest known theropods, they had already reached lengths of 3 m (10 ft). By the end of the Triassic Period, the well-known Plateosaurus had attained a length of 9 m (30 ft) and a weight of 1.8 metric tons. During the late Triassic and early Jurassic periods, prosauropods were the largest plant-eating dinosaurs. Sauropods Sauropods, which include such giants as Apatosaurus (formerly known as Brontosaurus) and Diplodocus, descended from prosauropods. By the middle of the Jurassic Period they had far surpassed all other dinosaurs in size and weight.

Some sauropods probably reached lengths of more than 25 m (more than 82 ft) and weighed about 90 metric tons. These dinosaurs walked on four pillarlike legs. Their feet usually bore claws on the inner toes, although they otherwise resembled the feet of an elephant. The sauropod backbone was hollow and filled with air sacks similar to those in a bird's vertebrae, and the skull was small in proportion to the animals' size. The food they ate was ground by stones in their gizzard, a part of their digestive tract. Indeed, sauropods may be compared to gigantic elephants, with the sauropods' long necks performing the function of an elephant's trunk, and their gizzard stones acting as the strong teeth of an elephant. Some sauropods, such as the late Jurassic Apatosaurus, used their long, thin tails as a whip for defense, while others used their tails as clubs. Ornithischian Dinosaurs In ancestral ornithischians the bony structure projecting down and back from each side of the hips was composed of two bones, so that their hips superficially resembled the hips of birds.

Early ornithischians were small bipedal plant-eaters, about 1 m (about 3 ft) in length. These animals gave rise to five kinds of descendants: stegosaurs, ankylosaurs, ornithopods, pachycephalosaurs, and ceratopsians. Stegosaurs Some ornithischians quickly became quadrupedal (four-legged) and relied on body armor and other physical defenses rather than fleetness for protection. Plated dinosaurs, such as the massive Stegosaurus of the late Jurassic Period, bore a double row of triangular bony plates along their backs. These narrow plates contained tunnels through which blood vessels passed, allowing the animals to radiate excess body heat or to warm themselves in the sun. Many also bore a large spined plate over each shoulder. Stegosaurs resembled gigantic porcupines, and they probably defended themselves by turning their spined tails toward aggressors. Ankylosaurs During the Cretaceous Period, stegosaurs were supplanted by armored dinosaurs such as Ankylosaurus. These animals were similar in size to stegosaurs but otherwise resembled giant horned toads.

Some even possessed a bony plate in each eyelid as well as large tail clubs. Their necks were protected by heavy bony rings and spines, indicating that these areas needed protection from the attacks of carnivorous dinosaurs. Ornithopods Ornithopods increased in variety from the middle Jurassic through the Cretaceous periods and became the most abundant plant-eating dinosaurs. They ranged in size from small runners that were 2 m (6 ft) long and weighed 15 kg (33 lb), such as Hypsilophodon, to elephantine cows that were 10 m (32 ft) long and weighed 4 metric tons, such as Edmontosaurus. These animals had flexible jaws and grinding teeth, which eventually surpassed those of modern cows in their suitability for chewing fibrous plants. The beaks of ornithopods became broader, earning them the name duck-billed dinosaur. Their tooth batteries became larger, their backs became stronger, and their forelimbs lengthened until their arms became elongated walking sticks, although ornithopods remained bipedal. The nose supported cartilaginous sacks or bony tubes, suggesting that these dinosaurs may have communicated by trumpeting.

Fossil evidence from the late Cretaceous Period includes extensive accumulations of bones from ornithopods drowned in floods, indicating that duck-billed dinosaurs often migrated in herds of thousands. A few superbly preserved Edmontosaurus skeletons encased within impressions of skin have been discovered in southeastern Wyoming. Pachycephalosaurs Pachycephalosaurs were small bipedal ornithischians with thickened skulls, flattened bodies, and tails surrounded by a latticework of bony rods. In many of these dinosaurs, such as the Pachycephalosaurusa large specimen more than 4 m (more than 13 ft) longthe skull was capped by a rounded dome of solid bone. Some paleontologists suggest that males may have borne the thickest domes and butted heads during mating contests. Eroded pachycephalosaur domes are often found in stream deposits from late in the Cretaceous Period. Ceratopsians The quadrupedal ceratopsians, or horned dinosaurs, typically bore horns over the nose and eyes, and had a saddle-shaped bony frill that extended from the skull over the neck.

These bony frills were well developed in the late Cretaceous Triceratops, a dinosaur which could reach lengths of up to 8 m (26 ft) and weights of more than 12 metric tons. The frill served two purposes: It protected the vulnerable neck, and it contained a network of blood vessels on its undersurface to radiate excess heat. Large accumulations of fossil bones suggest that ceratopsians lived in herds. Extinction Controversy surrounds the extinction of the dinosaurs. According to one theory, dinosaurs were slowly driven to extinction by environmental changes linked to the gradual withdrawal of shallow seas from the continents at the end of the dinosaurian era. Proponents of this theory postulate that dinosaurs dwindled in number and variety over several million years. An opposing theory proposes that the impact of an asteroid or comet caused catastrophic destruction of the environment, leading to the extinction of the dinosaurs. Evidence to support this theory includes the discovery of a buried impact crater (thought to be the result of a large comet striking the earth) that is 200 km (124 mi) in diameter in the Yucatï¿½n Peninsula of Mexico.

A spray of debris, called an ejecta sheet, which was blown from the edge of the crater, has been found over vast regions of North America. Comet-enriched material from the impact's fiery explosion was distributed all over the world. With radiometric dating (see Dating Methods: Radiometric Dating), scientists have used the decay rates of certain atoms to date the crater, ejecta sheet, and fireball layer. Using similar techniques to date the dramatic changes in the record of microscopic fossils, they have found that the impact and the dinosaur extinction occurred nearly simultaneously. Although large amounts of ash suggest that most of North and South America was devastated by fire from the impact, the longer-term planetwide environmental effects of the impact were ultimately more lethal to life than the fire. Dust blocked sunlight from the earth's surface for many months. Scorched sulfur from the impact site, water vapor and chlorine from the oceans, and nitrogen from the air combined to produce a worldwide fallout of intensely acidic rain. Scientists postulate that darkness and acid rain caused plant growth to cease. As a result, both the herbivorous dinosaurs, which were dependent on plants for food, as well as the carnivorous dinosaurs, which fed on the herbivores, were exterminated.

On the other hand, animals such as frogs, lizards, and small insect-eating turtles and mammals, which were dependent on organisms that fed on decaying plant material, were more likely to survive. Their survival indicates that, in most areas, the surface of the earth did not freeze. Studying Dinosaurs Dinosaur remains are usually buried in sediments deposited on land. These remains are likely to be found in regions where the silts and sands spread by rivers of the Mesozoic Era are exposed. Remains are easier to find in arid badlandsrugged, rocky areas with little vegetation, where the sediments are not covered by soil. The excavation of large skeletal remains involves painstaking procedures to protect the remains from damage. Less than 3000 dinosaur specimens that have been collected to date, and only 50 skeletons of the 300 known varieties of dinosaurs are completely known. Probably less than 10 percent of the varieties of dinosaurs that once lived have been identified. The shape of dinosaur bones provides clues to how these animals interacted with each other. These bones also reveal information about body form, weight, and posture.

Surface ridges and hollows on bones indicate the strength and orientation of muscles, and rings within the bones indicate growth rates. Diseased, broken, and bitten bones bear witness to the hazards of life during the dinosaurian age. Cavities in bones reflect the shape of the brain, spinal cord, and blood vessels. Delicate ossicles, or small bony structures in the skull, reveal the shape of the eyeball and its pupil. The structure of the skull and fossilized contents of the abdominal region provide clues to diet. Organic molecules are also preserved within bones in trace quantities. By studying isotopes of atoms within these molecules, scientists can gather evidence about body-heat flow and about the food and water consumed by dinosaurs. Impressions in sediment depict skin texture and foot shape, and trackways provide evidence about speed and walking habits. Several historically important dinosaur discoveries were made by Americans. During the last part of the 19th century, paleontologist Othniel Charles Marsh and his collectors explored the western United States for dinosaurian remains. They identified many genera that have since become household names, including Stegosaurus and Triceratops.

In the early part of the 20th century, paleontologists Barnum Brown, Charles Sternberg, and Sternberg's sons demonstrated that the area now known as Dinosaur Provincial Park in Alberta, Canada, is the richest site for dinosaurian remains in the world. The philanthropist Andrew Carnegie sponsored excavations in the great Jurassic quarry in Utah, which subsequently became Dinosaur National Monument. Beginning in 1922, explorer Roy Chapman Andrews led expeditions to Mongolia that resulted in the discovery of dinosaur eggs. More recently, Luis Alvarez, a particle physicist and Nobel laureate, and his son geologist Walter Alvarez discovered evidence of the impact of an asteroid or comet that coincided with the extinction of the dinosaurs. Among foreign scholars, the German paleontologist Werner Janensch beginning in 1909 led well-organized dinosaur collecting expeditions to German East Africa (modern Tanzania), where the complete skeletal anatomy of the gigantic Brachiosaurus was documented.

Giant plant-eating dinosaur unearthed | Wackbag.com Giant plant-eating dinosaur unearthed Likes Received: 1 WASHINGTON (Reuters) -- Scientists in Spain have found the fossilized remains of one of the largest animals ever to walk the Earth, a gargantuan plant-eating dinosaur up to 125 feet long and weighing as much as seven elephants. Turiasaurus riodevensis, named for the region and village in Spain where it was found, lived about 145 million years ago and was a sauropod, that familiar kind of dinosaur with a long neck, long tail and massive body that walked on four stout legs. It is the largest dinosaur ever found in Europe. Previous dinosaurs of this scale have been found mostly in the Americas and Africa. Other well-known sauropods include Apatosaurus (formerly known as Brontosaurus), Brachiosaurus and Diplodocus. This one is emblematic of a previously unrecognized branch of European sauropod evolution, the scientists said. Sauropods are the largest land animals in Earth's history.

"This discovery is the dream of a paleontologist," Luis Alcala of Fundacion Conjunto Paleontologico de Teruel-Dinopolis in Teruel, Spain, said by e-mail. "Really, I'm not dreaming?" Alcala and colleagues Rafael Royo-Torres and Alberto Cobos describe Turiasaurus on Thursday in the journal Science. The dinosaur came from a time right at the boundary between the latter two periods of the Age of Dinosaurs, the Jurassic and Cretaceous. Relatively little has been known about European dinosaurs dating from then. Scientists believe Turiasaurus spent its days munching plants in an area close to the shoreline of the ancient Tethys Sea, forerunner of the Mediterranean Sea. The first bones were found by Cobos and Royo-Torres in an abandoned wheat field near the village of Riodeva in northeastern Spain in May 2003, Alcala said. Alcala said Turiasaurus weighed between 40 and 48 metric tons and was between 118 and 125 feet long -- longer than an NBA basketball court. By comparison, Tyrannosaurus rex was about 45 feet long and six tons.

The humerus, the bone in the front leg that extends from shoulder to elbow, was as big as a full-grown man. Turiasaurus rivals the size of the largest known dinosaurs, all sauropods, and its remains were more complete than those of many of them. These include the African giant Paralititan, Seismosaurus in North America and Argentinosaurus and Puertasaurus in South America. "It's a tremendously large animal, not quite to the scale of the 'land whales,' things like Argentinosaurus and Puertasaurus or Sauroposeidon. But it's pretty darned big," said Thomas Holtz, a dinosaur expert at the University of Maryland who was not involved in the research. "This is the first real super-giant from Europe," Holtz said. Other fossils found at the site indicated Turiasaurus lived alongside other dinosaurs, including biped meat eaters, other sauropods and plant eaters similar to the armored Stegosaurus, as well as turtles and crocodile-like reptiles. The researchers said Turiasaurus was more primitive from an evolutionary perspective than other known giant sauropods.

The team found 70 pieces of the fossilized remains representing about a quarter of its skeleton, including fragments of the skull, leg, back, toes, ribs, shoulder blade and teeth. Finding most of the key parts -- the only vital missing piece was the pelvic girdle -- allowed them to ascertain its dimensions and appearance. Dinosaurs, Etymology and History | Wyzant Resources Dinosaurs Where does the word "dinosaur" come from? The word dinosaur really does not mean terrible-lizard. Actually, it was originally defined to mean fearfully-great lizard by Richard Owen in 1842. The Greek word deinos, when used as a superlative, means fearfully-great, as used by Homer in The Iliad. It became simplified over time, as an adjective, to mean terrible. In reality, scientists believe that dinosaurs are neither terrible nor lizards! When the secrets of prehistoric life were unearthed, scientists tried to picture the feelings of those confronted by the great monsters whose fossil bones were coming again to light.

Sir Richard Owen (English, 1804-1892) named a few of these creatures, from Greek words. Thus there was the terrible (fearful) lizard (Gk., deinos, fearful, plus sauros, lizard). Dictionary of Word Origins by Joseph T. Shipley Sir Richard Owen was an English zoologist and paleontologist (palaeontologist, British). In 1856, he was appointed superintendent of the natural history department of the British Museum and was instrumental in the establishment of the separate British Museum (Natural History), now the Natural History Museum, becoming its first director in 1881. In addtion to all of his important scientific publications, Sir Owen named and reconstructed numerous celebrated fossils, including the giant moa bird Dinornis, the dinosaur Iquanodon, and the earliest bird, the Archaeoptryx. The Greek term deinos was: expressive of the quality of objects which, from their vastness, magnitude, etc., inspire fear, awe, reverence, power, etc. from Pickering: Comprehensive Lexicon of the Greek Language, 1873 edition.

Richard Owens first published definition of Dinosauria was fearfully great lizards, and he noted that the groups peculiar anatomical features (fused sacrum, pachyderm-like limbs) were all manifested by creatures far surpassing in size the largest of existing reptiles. His arch-rival, Thomas Huxley (1869), even questioned if the name Dinosauria was appropriate after some members of the group turned out to be small. The term terrible lizard is now often wrongly interpreted to indicate a frighteningly vicious nature for dinosaurs, but this was not Owens original idea, and results from the different range of meanings terrible can have in English. Contrary to the version of history given in many current books, Owen did not introduce the term Dinosauria in a famous address to the British Association for the Advancement of Science at Plymouth, England, on August 2, 1841.

Detailed accounts of Owens spoken lecture in a number of respected journals of the day (including The Literary Gazette and The Athenaeum) make no mention of the Dinosauria, and indicate that Owen treated Megalosaurus and Iguanodon only as large, if unusual, lizard-like reptiles. It was only in the much-revised and expanded published version of the report, that appeared nearly a year later, in 1842, that Owen formally named and described the Dinosauria as a new order of reptiles, distinguished in particular by the presence of a sacrum with five fused vertebrae, as found in large mammals and birds. Recent research by the British geologist, Hugh Torrens, has documented how Owen came to his break-through insights between 1841 and 1842. Owens reasons for erecting the Dinosauria are still partly misinterpreted. History of Dinosaurs Dinosaurs are the best examples of success and adaptation known. They ruled the Earth longer than any other land animals, including humans (about 150 million years), and gave rise to birds. Dinosaurs and humans did not coexist.

The death of the last dinosaur and the appearance of the first human (genus homo) is estimated to be separated by about 64 or 65 million years. Paleontologists have constructed a timeline in which dinosaurs existed in the Mesozoic Era which theoretically started about 248 million years ago and which was divided into the Triassic Period, then the Jurassic Period, and finally the Cretaceous Period said to have ended about 65 million years ago when dinosaurs became extinct and then a new Cenozoic Era began in which mankind is said to have evolved or came into existence. As stated above, authorities maintain that mankind [Cenozoic Era] did not exist in the same time period or era as the previous period of the dinosaurs [Mesozoic Era], but mankind should not feel too self assured about the absence of threats from dinosaurs. If the dinosaurs could not touch them, there were (and are) plenty of other dangers that people must be aware of. Time present and time past Are both perhaps present in time future And time future contained in time past. -T.S. Eliot Turning ones back on present dangers and pain Cancels out the advantages we have from past gain.

Dinosaurs were not warm-blooded like modern mammals, nor were they cold-blooded like modern lizards. Most specialists believe that dinosaurs were dinosaur-blooded, a condition that combines warm-bloodedness with a changing metabolism over the animals lifetime. A new unofficial term, metathermy, has been proposed for this condition in Mesozoic dinosaurs. Popular books, movies, and TV specials are not necessarily completely accurate. They often contain errors and outdated information, and may reflect the personal bias of the writer. Most dinosaur books and TV scripts are not reviewed by professional dinosaur paleontologists. All of the dinosaurs did not live and die at the same time. The distance in time between Tyrannosaurus and Apatosaurus (formerly called Brontosaurus) is the same amount of time as between Tyrannosaurus and the first humans, about 65 million years. Of the (approximately) 350 known mesozoic dinosaurs, only one to two dozen species faced the final extinction in North America.

Mammals did not arise after the dinosaurs, and there is no evidence that they helped drive the dinosaurs into extinction by eating their eggs. Mammals and dinosaurs both appeared in the Upper Triassic Period. The End of the Dinosaurs Did an asteroid (or comet) kill the dinosaurs? The asteroid theory of dinosaur extinction has not been proven nor solved. Proof that an asteroid hit the Earth at the end of the Cretaceous does not automatically prove that it killed the dinosaurs. Most dinosaur specialists are willing to accept that an asteroid hit the Earth, but not that it was the one cause of the Mesozoic extinctions. However, most articles on this topic are written by non-dinosaur specialists. The remaining unsolved question is when did the asteroid hit? Was it before, during, or after the classic dinosaurs went extinct? It should be remembered that birds are the direct descendants of one dinosaur group, the Theoropoda; so in a way, dinosaurs are not extinct. All big monster reptiles from the prehistoric past are not dinosaurs. They represented less than 10% of the 40 groups of reptiles from the Mesozoic Era.

Pterodactyls, sea-serpents, giant lizards, pelycosaurs, and other big prehistoric beasts are not dinosaurs. Monsters and dragons are the products of fiction and mythology while dinosaurs were real. Archaeologists do not dig up dinosaurs. Archaeology (a subdivision of anthropology) deals only with mankind and covers the last four million years. Paleontology (a combination of geology and biology), deals with all fossils and covers the last 3.5 billion years! The preceding material is based on information presented in The Top 10 Misconceptions about Dinosaurs compiled by M. K. Brett-Surman, Donald F. Glut, and Thomas R. Holtz of the National Museum of Natural History, Smithsonian Institution, Washington, D.C. as seen on its Internet site.

Question: The giant Jurassic plant-eating dinosaur now known as the Apatosaurus was formerly known by what name ?
Answer: BRONTOSAURUS