THE COMPLETE DINOSAUR PDF, EPUB, EBOOK

James O. Farlow, M.K. Brett-Surman | 768 pages | 01 Aug 1999 | Indiana University Press | 9780253213136 | English | Bloomington, IN, United States Dinosaur Facts | HowStuffWorks

Bedtime exploit this dynamic perfectly; by the last page, the dress-up dinosaur has finally settled down for a night's sleep, after winning a series of dramatic battles against a playground slide, a bowl of spaghetti, and talking grown-ups. Believe it or not, until 20 years ago, most kids learned about dinosaurs from mounted skeletons in museums, and not computer-animated documentaries on The Discovery Channel or the BBC. Because they're so big and so unfamiliar, dinosaur skeletons are somehow less creepy than the skeletons left by modern wolves or big cats or human beings, for that matter. In fact, many kids prefer their dinosaurs in skeleton form—especially when they're putting together scale-sized models of a Stegosaurus or Brachiosaurus! Finally, and most important, dinosaurs are really, really cool. If you don't grasp that simple idea, then you probably shouldn't be reading this article in the first place. Perhaps you'd be more comfortable learning about birding or potted plants! In reality, the mosasaur was a smaller, frill-less aquatic creature. The scene in Jurassic Park when the dino sneezes on the kid and sprays goo everywhere is pretty funny. That was a lot of slime. But regardless of the humor involved, the brachiosaurus couldn't sneeze due to its long neck. Apparently, the creature's neck was so long that a sneeze would likely have caused its head to explode. Dinosaurs existed starting about million years ago, and they disappeared completely only 65 million years ago. A lot has changed here on Earth in 65 million years, what with the rise of people and all. But while 65 million years is really long, that means there were still millions of years when dinosaurs were around. Stegosaurus and T. In Jurassic World: Fallen Kingdom, our heroes get trapped in a jail cell underneath the mansion of their once-patron, now-evil dinosaur trader. They use a small but thick-skulled dinosaur to escape by tricking it into smashing through the wall and then through the cell door. As such, smashing through a brick wall and then a steel gate to save our heroes, while good cinema, isn't accurate. Movies love to make their monsters bulletproof to some degree. It makes killing the bad guy that much more interesting. But when movies place dinosaurs, which are really just animals, as the bad guys, it gets a little bit weird. Dinosaur hides could've been thick, but more like how a bear's hide is thick. Like any hunter could tell you, shooting a bear with a 9mm handgun is likely to make it upset, but something with a larger caliber would do the trick just fine. It's no different with the T. Definitely not bulletproof. Turns out the internet was getting so upset over a woman outrunning a T. They were just too big. They could, however, walk very quickly. They must've been fast in some way, right? Though T. That's a speed-walking record, surely. Regardless, the scene in Jurassic Park in which the T. After hatching, the babies came out small — roughly the size of a turkey and covered in fuzz. They lost much of their fuzz over time, keeping only small patches on their heads and tails into adulthood. It's probably a safe bet, then, to say that many bird-like dinosaurs looked like ducklings during their juvenile years. Any movie showcasing a baby dinosaur cracking out of its egg to reveal scales isn't quite accurate. The king of dinosaurs couldn't even roar? Now it just seems a lot less scary. But wait. If it couldn't roar, what sound could it make? The T. Knowing that the T. Over two decades of the Jurassic Park T. But cooing? Oh, how the mighty fall. Many films seem to show dinosaurs as slow, lumbering, lethargic giants. And sure, T. Dinosaurs had massive hearts that allowed them to move quickly and pumped the necessary blood to their immense muscles. This means that they could move their limbs at an alarming speed and, therefore, move very quickly. It's a common trope in the Jurassic Park series that the T. But of course they can see things that size — how could they not? How can a creature with eyes that big, known for its predatory nature, not see prey standing still? Imagine a T. It would bump into trees pretty frequently, and it surely would have starved to death. All the prey had to do was stand completely still and voila — perfectly safe. A predator prowling for food because it's hungry is aggressive, yes? So, naturally, a predatory dinosaur would've been the same way. But the dinosaurs in Jurassic Park are really aggressive all the time. Raptors continue stalking people after already eating several of them. Pterodactyls snatch humans after escaping their enclosure. The dinosaurs in this fictional theme park were probably well fed. It's a kind of zoo, after all. If they were well fed, then what really would've happened was that they would simply have ignored the running people because they were full. The acid-spitting, shrunken menace was distorted by artistic license, once again. The first dinosaurs existed on pretty much an equal footing with their archosaur, crocodile and pterosaur cousins; if you traveled back to the late Triassic period, you would never have guessed that these reptiles, above and beyond all the others, were fated to inherit the earth. That all changed with the still-mysterious and little-known Triassic- Jurassic Extinction Event, which wiped out the majority of archosaurs and therapsids "mammal-like reptiles" but spared the dinosaurs. No one knows exactly why; it may have had something to do with the upright posture of the first dinosaurs or perhaps their slightly more sophisticated lungs. By the start of the Jurassic period, dinosaurs had already started to diversify into the ecological niches left abandoned by their doomed cousins--the most important such event being the late Triassic split between saurischian "lizard-hipped" and ornithischian "bird-hipped dinosaurs. Most of the very first dinosaurs can be considered saurischians, as can the "sauropodomorphs" into which some of these early dinosaurs evolved--slender, two-legged herbivores and omnivores that eventually evolved into the giant prosauropods of the early Jurassic period and the even bigger sauropods and titanosaurs of the later Mesozoic Era. As far as we can tell, ornithischian dinosaurs--which included ornithopods , hadrosaurs , ankylosaurs , and ceratopsians , among other families-- could trace their ancestry all the way back to Eocursor, a small, two-legged dinosaur of late Triassic South Africa. Eocursor itself would have ultimately derived from an equally small South American dinosaur, most likely Eoraptor, that lived 20 million or so years earlier--an object lesson in how such a vast diversity of dinosaurs could have originated from such a humble progenitor. Share Flipboard Email. Bob Strauss. Science Writer. What Do You Call a Person Who Studies Dinosaurs?

Most titanosaurids were about 40 to 50 feet long, but a few became gigantic. The titanosaurids lived mainly in the southern hemisphere during the Cretaceous Period, surviving there as the northern-hemisphere sauropods became extinct. The theropods were all the predatory dinosaurs except the herrerasaurians. From the smallest dinosaurs to the largest meat-eaters, the theropods had the most different kinds of saurischian dinosaurs of all suborders. These two-legged meat-eaters had clawed feet with no more than three functional toes. The wings and feet of birds are similar to the arms and feet of theropod skeletons. Also like birds, all theropods to some extent had hollow hones. The best ancestral bird is the small, feathered, theropodlike Archaeopteryx from the Late Jurassic. The theropods evolved into two major groups: the Ceratosauria, with flexible tails; and the Tetanurae, with stiff tails. All the earliest theropods were ceratosaurians. Their fossil record is from the Late Triassic through the Late Jurassic. The tetanurans appeared in the Middle Jurassic, diversified in the Late Jurassic, and were the main northern-hemisphere predators until the Late Cretaceous. It was small and nimble and had a long, slender skull with many teeth. Families: Halticosauridae and Ceratosauridae : Dilophosaurus, which lived during the Early Jurassic, had a double crest on its head. Ceratosaurus was from the Late Jurassic and had a horn on its head. Both were from North America and are examples of later members of the ceratosaurians. After the Late Jurassic, ceratosaurians apparently vanished in the northern hemisphere but survived in South America. Family: Abelisauridae : The abelisaurids are a group of medium to large African and South American theropods characterized by short, tall skulls. Carnotaurus from Argentina and Majungatholus from Madagascar are similar with the exception that Carnotaurus has two large horns on the skull. The tetanurans, the most advanced theropods, included several groups where the relationships are not well understood. Crests and other decorations on the head were usually not present. Their hands had three or fewer fingers, and the "thumb" usually had the largest claw. It was the smallest theropod, about three feet long and lightly built. Family: Coeluridae : Ornitholestes and Coelurus, which lived during the Late Jurassic in western North America, were fast-running, lightly built theropods that were two to three feet tall at the hips and from six to ten feet long. Family: Carcharodontosauridae : This group of giant theropods from Gondwana includes enormous predatory dinosaurs, Giganotosaurus from Argentina and Car-charodontosaurus from North Africa. Family: Therizinosauridae : The therizinosaurids were apparently herbivorous or omnivorous theropods known from the Late Cretaceous of Asia and North America. The unusual, birdlike pelves and almost prosauropod-like skulls of therizinosaurids have resulted in uncertainty about their evolutionary position, but they have recently been shown to be theropods closely related to the Ornithomimidae. Family: Spinosauridae : Spinosaurids are a distinctive group of theropods with long, crocodile-like snouts and elongated vertebral spines that may have formed sail-like structures on their backs. Family: Oviraptorisauridae : Another curious theropod from the Cretaceous of Asia is Oviraptor, which has a tall, highly pneumatic skull with a turtle-like beak. Oviraptor got its name "egg predator" because specimens were found in Mongolia with what were originally thought to be nests of ceratopsian eggs. Family: Allosauridae : This family is typical of the larger Jurassic and Early Cretaceous theropods that were from 15 to 35 feet long or longer. The biggest allosaurid may have been more than 40 feet long. Allosaurids were slender but dangerous predators. Family: Tyrannosauridae : Most dramatic of all the theropods were the tyrannosaurids, which probably came from allosauridlike ancestors at the beginning of the Late Cretaceous. Unlike other tetanurans, they had massive bodies, unusually shaped heads, and small two-fingered hands. Some tyrannosaurids were nearly 50 feet long and became the largest meat-eating land animals known. The smallest, such as Nanotyrannus, were about 18 feet long. The medium-size tyrannosaurids, such as Albertosaurus and Daspletosaurus, were about 30 feet long. Family: Ornithomimidae : Many kinds of small theropods also arose in the Cretaceous. Their skeletons were birdlike. Most had changes in their front legs and hands for a powerful striking action. The "quick-strike" motion of the front limbs may have been the beginning of the power stroke of birds' wings. The "ostrich dinosaurs" or Ornithomimidae are known best from the Late Cretaceous of eastern Asia and western North America. They had small heads and they usually had no teeth. They had long necks and short, stiff backs. Their front limbs were long, and their powerful rear legs were built for speed. They are thought to have been the fastest dinosaurs. Family: Dromaeosauridae : Deinonychus and other "sickle claw" theropods are among the best-studied dinosaurs. The discovery of Deinonychus supported the idea of a bird-dinosaur relationship and started the debate about dinosaurs being warm-blooded. Each foot had a large, sickle-shaped claw on the second toe. The end of the tail had vertebrae that locked together to make it stiff. Family: Troodontidae : This group of "sickle claw" theropods had large brains and large eyes that faced forward. Some, such as Troodon and Saurornithoides, may have been almost as smart as some mammals. The earliest ornithischian dinosaur was Pisanosaurus, a three-foot-long, two- legged bipedal plant-eater from the late Middle Triassic of Argentina. All ornithischians were plant-eaters. Later ornithischians split into three advanced groups: heavy, armored plant-eaters that walked on all fours; specialized dome-headed dinosaurs and horned dinosaurs; and two-legged plant-eaters that included Iguanodon and duckbilled dinosaurs. Other primitive ornithischians are usually classified in this family. All fabrosaurids were small bipedal plant-eaters. The best-known fabrosaurid is Lesothosaurus, also from the Early Jurassic of southern Africa. The pelvis of Lesothosaurus shows some features that put it at the bottom of ornithischians. Scutellosaurus from the Early Jurassic of western North America was protected by small bony plates resembling the larger plates of later armored ornithischians. Stegosaurs were the main armored dinosaurs of the Jurassic Period; ankylosaurs remained in the background. But ankylosaurs replaced stegosaurs in the Cretaceous Period. Scelidosaurus was very much like both groups. It was from the Early Jurassic of England and it walked on all four limbs quadrupedal. It had stegosaurlike teeth, an ankylosaurlike pattern of armor plates and spines, and a pelvis like Scutellosaurus. The armor was a double row of large bony plates that ran along the back from behind the head to the tail. Sharp spines on the end of the tail were used as a weapon against predators. During the Early Cretaceous, ankylosaurs replaced stegosaurs everywhere except in India. Ankylosaurs were different from stegosaurs because they had flexible body armor rather than a double row of tall plates. They were also closer to the ground, with only a slight arch, if any, to their backs. The heads of stegosaurs were long and narrow, but ankylosaurs had short, board skulls. Instead of tail spines, ankylosaurs had shoulder spines or tail clubs for defense. Family: Nodosauridae : The more primitive ankylosaurians, including all Jurassic and southern-hemisphere genera, belong in this family. Some nodosaurids had large, cone-shaped spines along the neck and shoulders for protection. Family: Ankylosauridae : This family may have arisen during the Early Cretaceous from a nodosaurid ancestor. Ankylosaurid skulls had horns projecting from the back, giving them a triangular shape when viewed from above. One of the most widely-known carnosaurs was Velociraptor , which is considerably smaller than depicted in the "Jurassic Park" films. Sauropods , on the other hand, were enormous, four-legged herbivores like Brachiosaurus, Apatosaurus and Diplodocus. Dinosaurs with armored bodies and spiny tails were ankylosaurs. Ceratopians -- like Triceratops -- had frills and horns on their heads. But not every reptile that lived during the Mesozoic era was a dinosaur. In fact, a lot of extinct animals that people think of as dinosaurs aren't classified as dinosaurs. This is because they don't share one or more of dinosaurs' basic traits:. So because of their bone structure, habitat or other traits, these animals weren't technically dinosaurs. But they did leave behind same evidence that dinosaurs did -- fossils. Next, we'll look at what fossils can and can't tell us about dinosaurs' physical appearance. The earliest dinosaurs lived in a world that looked very different from the Earth we know today. Rather than being separated by expansions of ocean, the continents were packed together in a mass known as Pangea. Dinosaurs lived for about million years, and during that time, the continents gradually spread to form the shapes we recognize today. The discovery of a new dinosaur-or new fossils of a poorly known dinosaur-may change the family tree. We will never know all the different dinosaur groups that lived, so their family tree will always be incomplete. Dinosaurs are classified as reptiles, but all reptiles do not form a single clade a group that includes a common ancestral species and all the species that descended from it. There are two reptilian clades. One clade includes all living reptiles, dinosaurs, ichthyosaurs, plesiosaurs, and birds the Sauropsida. The other clade is the mammals and the extinct mammallike reptiles the Theropsida. Crocodilians and birds are more closely related to each other than either is to lizards and snakes. They are part of a smaller sauropsid clade, the Archosauria. Lizards and snakes are in the clade Lepidosauria. Archosaurs had a large opening in the front of each eye. As the many groups of archosaurs evolved, this antorbital fenestra "window in front of the eye" sometimes closed in crocodilians and the later plant-eating dinosaurs or merged with the nostril in pterosaurs. It was the largest opening in the skull of the large predatory dinosaurs, such as Allosaurus and Tyrannosaurus,. The earliest archosaurs are found in Permian rocks, formed before the Mesozoic Era began. In the beginning of the Mesozoic, when animal life was recovering from the worst mass extinction in the world's history, the archosaurs expanded and quickly spread. Most of those first archosaurs were extinct by the end of the Triassic Period, but the Pterosauria, Saurischia, and Ornithischia survived to the end of the Mesozoic, and the Crocodilia survived to the present. Birds have not been found in the Triassic, although some puzzling Triassic birdlike animals have recently been discovered in Asia, Europe, and Texas. Two important evolutionary changes took place among the archosaurs. They changed from-sprawling, lizardlike animals to animals that walked with their legs held directly under their bodies. The other change was from a cold-blooded, lizardlike metabolism the way a body uses energy to a warm-blooded, birdlike metabolism. These changes did not take place in all archosaurs, but they happened in the dinosaurs. Crocodilians are the only surviving example in which those changes did not occur; birds are the only surviving group in which they did occur. Warm-bloodedness may have appeared early in the dinosaur-bird clade, so that almost all dinosaurs were warm-blooded. This trait may have been inherited from a common ancestor dinosaurs shared with birds. Or, these changes may have happened after dinosaurs and birds separated, so that only a few advanced predatory dinosaurs were warm-blooded. The ancestors of dinosaurs developed a stronger ankle. This kind of ankle occurs in pterosaurs, dinosaurs, and birds. Lagosuchus, Lagerpeton, and Pseudolagosuchus were small, bipedal they walked on two legs archosaurs with advanced ankles and other features that suggest they were closely related to dinosaurs. The Linnaean System of Classification. Types of Dinosaurs | HowStuffWorks

There are currently about named species, but this probably represents a fraction of the dinosaurs that ever existed. Dinosaurs ranged in size from immense to tiny, and they came in a range of shapes. Today's dinosaur classifications come from these differences in shape and size. Carnivorous dinosaurs were all theropods , bipedal animals with three-toed feet. Carnosaurs were a small, agile type of theropod. One of the most widely- known carnosaurs was Velociraptor , which is considerably smaller than depicted in the "Jurassic Park" films. Sauropods , on the other hand, were enormous, four-legged herbivores like Brachiosaurus, Apatosaurus and Diplodocus. Dinosaurs with armored bodies and spiny tails were ankylosaurs. Ceratopians -- like Triceratops -- had frills and horns on their heads. But not every reptile that lived during the Mesozoic era was a dinosaur. In fact, a lot of extinct animals that people think of as dinosaurs aren't classified as dinosaurs. This is because they don't share one or more of dinosaurs' basic traits:. So because of their bone structure, habitat or other traits, these animals weren't technically dinosaurs. But they did leave behind same evidence that dinosaurs did -- fossils. Next, we'll look at what fossils can and can't tell us about dinosaurs' physical appearance. The earliest dinosaurs lived in a world that looked very different from the Earth we know today. Rather than being separated by expansions of ocean, the continents were packed together in a mass known as Pangea. Dinosaurs lived for about million years, and during that time, the continents gradually spread to form the shapes we recognize today. Dinosaurs continued to live on every continent -- there are even fossils buried under the ice in Antarctica. Prev NEXT. Modern reptiles like turtles and crocodiles are cold-blooded, or "ectothermic," meaning they need to rely on the external environment to maintain their internal body temperatures. Modern mammals and birds are warm-blooded, or "endothermic," possessing active, heat-producing metabolisms that maintain constant internal body temperature, no matter the external conditions. There's a solid case to be made that at least some meat-eating dinosaurs—and even a few ornithopods —must have been endothermic since it's hard to imagine such an active lifestyle being fueled by a cold-blooded metabolism. On the other hand, it's unlikely that giant dinosaurs like Argentinosaurus were warm-blooded since they would have cooked themselves from the inside out in a matter of hours. Fierce carnivores like Tyrannosaurus rex and Giganotosaurus get all the press, but it's a fact of nature that the meat- eating "apex predators" of any given ecosystem are tiny in number compared to the plant-eating animals on which they feed and which themselves subsist on the vast amounts of vegetation needed to sustain such large populations. By analogy with modern ecosystems in Africa and Asia, herbivorous hadrosaurs , ornithopods , and to a lesser extent sauropods , probably roamed the world's continents in vast herds, hunted by sparser packs of large-, small-, and medium-sized theropods. It's true that some plant-eating dinosaurs like the Stegosaurus had such tiny brains compared to the rest of their bodies that they were probably only a little smarter than a giant fern. But meat-eating dinosaurs large and small, ranging from Troodon to T. These reptiles required better-than-average sight, smell, agility, and coordination to reliably hunt down prey. Let's not get carried away, though—even the smartest dinosaurs were only on an intellectual par with modern ostriches. Many people mistakenly believe that mammals "succeeded" the dinosaurs 65 million years ago, appearing everywhere, all at once, to occupy the ecological niches rendered vacant by the K-T extinction event. The fact is, though, that early mammals lived alongside sauropods, hadrosaurs, and tyrannosaurs usually high up in trees, away from the heavy foot traffic for most of the Mesozoic Era. In fact, they evolved at around the same time—during the late Triassic period—from a population of therapsid reptiles. Most of these early furballs were about the size of mice and shrews, but a few like the dinosaur-eating Repenomamus grew to respectable sizes of 50 pounds or so. It may seem like nitpicking, but the word "dinosaur" applies only to land-dwelling reptiles possessing a specific hip and leg structure, among other anatomical characteristics. As large and impressive as some genera such as Quetzalcoatlus and Liopleurodon were, flying pterosaurs and swimming plesiosaurs ichthyosaurs and mosasaurs weren't dinosaurs at all—and some of them weren't even all that closely related to dinosaurs, save for the fact that they're also classified as reptiles. While we're on the subject, Dimetrodon —which is often described as a dinosaur—was actually an entirely different kind of reptile that flourished tens of millions of years before the first dinosaurs evolved. Rather, the process of extinction dragged on for hundreds, and possibly thousands, of years, as plunging global temperatures, lack of sunlight, and the resulting lack of vegetation profoundly altered the food chain from the bottom up. Some isolated dinosaur populations, sequestered in remote corners of the world, may have survived slightly longer than their brethren, but it's a sure fact that they are not alive today. Share Flipboard Email.

Why Do Kids Like Dinosaurs?

Constantly compared to the Tyrannosaurus rex, the Giganotosaurus was one of a handful of dinosaurs that rivaled, or possibly exceeded, the creature in size. University of Kansas paleontologists are comparing the bones of a new T. Could this exciting find help bridge the gaps between Africa's late Cretaceous fossil record and that of other continents? OK, hop in your time machine and go back 67 million years or so to the Cretaceous period. Then find a Tyrannosaurus rex and challenge it to a race. Sounds crazy, huh? Could you really outrun a Tyrannosaurus rex? Learn about Monoclonius, Late Cretaceous dinosaurs and dinosaurs of all eras. The recently discovered large theropod Abelisaurus comahuensis, from Patagonia is argentina, looked a little like Albertosaurus from Alberta, Canada, particularly in its size and lifestyle. Find out more about the Late Cretaceous dinosaurs. Albertosaurus was an older "cousin" to the better-known Tyrannosaurus. In many ways the two were similar: the head was large compared to the body, the tiny forearms had only two fingers each is and the long tail balanced the body over two powerful back legs. Anchiceratops was discovered along the Red Deer River in Alberta in Learn more about the Anchiceratops and Late Cretaceous Dinosaurs. The ornithomimid is anserimimus, has the name "goose mimic. With a thigh bone over seven and a half feet long, longer than any other femur known is antarctosaurus was a sauropod of spectacular proportions. Find out more about this and other Late Cretaceous dinosaurs. Aralosaurus is from Kazakhstan in the Soviet Union. It is known only from a nearly complete skull that is missing the front of the snout and all of the lower jaw, but no skeleton. Learn more about this Late Cretaceous duckbilled dinosaur. In , British paleontologist Richard Lydekker published the first description of sauropod dinosaurs from South America that had been unearthed in Patagonia is argentina. One of these was the Argyrosaurus. Learn more about this Late Cretaceous dinosaur. Arrhinoceratops is a rare ceratopsian known from only one skull that lacks a lower jaw. This single specimen was found in along the Red Deer River of Alberta by an expedition from the University of Toronto. This carnivorous dinosaur was named more than one hundred years ago for an unusual tooth found in the Judith River Badlands of northern Montana. When it was discovered, much of the West was still wild. Avaceratops lammersi was a small ceratopsid known from a single skeleton found in the Judith River Formation of Montana in Learn more about the Avaceratops and other Late Cretaceous dinosaurs. Avimimus 'bird mimic' was a small, lightly built theropod from the Upper Cretaceous Djadokhta Formation of Mongolia. Much of the buzz has now shifted to Eoraptor , discovered in , a tiny about 20 pounds South American dinosaur whose plain-vanilla appearance would have made it a perfect template for later specialization by some accounts, Eoraptor may have been ancestral to lumbering, four-footed sauropods rather than agile, two-legged theropods. A recent discovery may overturn our thinking about the South American origin of the first dinosaurs. In December of , paleontologists announced the discovery of Nyasasaurus , which lived in a region of Pangaea corresponding to present-day Tanzania, in Africa. Shockingly, this slim dinosaur dates to million years ago, or about 10 million years before the putative first South American dinosaurs. Still, it may yet turn out that Nyasasaurus and its relatives represented a short-lived offshoot of the early dinosaur family tree, or that it was technically an archosaur rather than a dinosaur; it's now classified, somewhat unhelpfully, as a "dinosauriform. These early dinosaurs spawned a hardy breed that quickly at least in evolutionary terms radiated out to other continents. The first dinosaurs quickly made their way into the region of Pangea corresponding to North America the prime example is Coelophysis , thousands of fossils of which have been discovered at Ghost Ranch in New Mexico, and a recent discovery, Tawa , has been adduced as further evidence for the South American origin of dinosaurs. Small to medium-sized carnivores like Podokesaurus soon made their way to eastern North America, then onward to Africa and Eurasia a latter example being the western European Liliensternus. The first dinosaurs existed on pretty much an equal footing with their archosaur, crocodile and pterosaur cousins; if you traveled back to the late Triassic period, you would never have guessed that these reptiles, above and beyond all the others, were fated to inherit the earth. That all changed with the still-mysterious and little-known Triassic-Jurassic Extinction Event, which wiped out the majority of archosaurs and therapsids "mammal-like reptiles" but spared the dinosaurs. No one knows exactly why; it may have had something to do with the upright posture of the first dinosaurs or perhaps their slightly more sophisticated lungs. By the start of the Jurassic period, dinosaurs had already started to diversify into the ecological niches left abandoned by their doomed cousins--the most important such event being the late Triassic split between saurischian "lizard-hipped" and ornithischian "bird-hipped dinosaurs. Most of the very first dinosaurs can be considered saurischians, as can the "sauropodomorphs" into which some of these early dinosaurs evolved-- slender, two-legged herbivores and omnivores that eventually evolved into the giant prosauropods of the early Jurassic period and the even bigger sauropods and titanosaurs of the later Mesozoic Era. As far as we can tell, ornithischian dinosaurs--which included ornithopods , hadrosaurs , ankylosaurs , and ceratopsians , among other families--could trace their ancestry all the way back to Eocursor, a small, two-legged dinosaur of late Triassic South Africa. Eocursor itself would have ultimately derived from an equally small South American dinosaur, most likely Eoraptor, that lived 20 million or so years earlier--an object lesson in how such a vast diversity of dinosaurs could have originated from such a humble progenitor.

https://static.s123-cdn-static.com/uploads/4638245/normal_601fa53fba42c.pdf https://uploads.strikinglycdn.com/files/3bededdf-51be-4b36-ae95-01a7ffda443b/die-modenarrheiten-ein-spiegelbild-der-zeiten-und-sitten-fur- das-deutsche-volk-288.pdf https://static.s123-cdn-static.com/uploads/4643731/normal_60200dd5e5bd2.pdf https://files8.webydo.com/9585811/UploadedFiles/B07185DE-FA0C-C42E-67CB-D91A6AF0293F.pdf https://files8.webydo.com/9586543/UploadedFiles/E47F6E7D-8D61-E8A9-4F6E-8D020445EDA0.pdf https://uploads.strikinglycdn.com/files/c7eb545b-66c1-4918-be5d-6b46020c14b3/die-besten-scherzfragen-fur-senioren-und-kinder-505-quiz- und-denkaufgaben-fur-jung-und-alt-95.pdf https://uploads.strikinglycdn.com/files/330b4050-8864-4e2d-82d4-d95867394a5b/das-tal-den-bewasserern-brechts-kreidekreis-stuck-und- auffuhrungspraxis-891.pdf