Over many years scientists have developed many different theories to why the dinosaurs became extinct; some are much more known while others and thought to be the truth and others and not known and thought to be a lie.
Faced with an evolving group of competing organisms -- the mammals -- perhaps dinosaurs were driven to extinction by competition. It over-turned many of the existing explanations and was thoroughly rejected by a large majority of the scientists at the time.
Body For about the first half of the 20th century, both scientists and the general public regarded dinosaurs as slow, unintelligent cold-blooded animals, often told to have a brain with the size of a peanut. The dinosaurs were around for roughly million years.
Fossil bones of what were undoubtedly dinosaurs were discovered in New Jersey in the late s and were probably discussed at the meetings of the American Philosophical Society in Philadelphia.
Not all of these names are valid taxahowever.
Even dinosaurs which survived would have lost many sources of food and could not survive. The specimens of Archaeopteryx contain particular anatomic features that also are exclusively present in certain theropods OviraptorVelociraptorDeinonychusand Troodon, among others.
Compared with most of their contemporaries, dinosaurs had an improved stance and posture with a resulting improved gait and, in several independent lineages, an overall increase in size. Knowledge of these, based on fragments of fossil bone, has slowly come to light, and there is now a fairly definite record from Cretaceous rock strata of other ancestral birds related to the living groups of loonsgrebesflamingoscranesparrotsand shorebirds —and thus indication of early avian diversity.
A variety of new theropods of all sizes were widespread; stegosaurs no longer existed; and the ankylosaurs were represented by a collection of new forms that were prominent in the North America and Asia. The first part of my research is devoted to the different hypotheses concerning the extinction event and the catastrophic effects they would have had on our planet at the time.
The Catastrophists believe that a huge catastrophic event took place, killing all of the dinosaurs. Origin and relationships of dinosauria. The theory states that there is a faint companion star to our sun with an orbit that comes close to the sun about every 26 million years.
The search is ever ongoing, and that is why it is possible that, in ten years time, what I have written here may no longer be valid.
It became known as the Maidstone Iguanodon, after the village where it was discovered. Scientists believed that the Asteroid would have travelled times faster than a jet airliner. In doing so, I have grouped my research under 2 main chapters.
In order to understand extinction, it is necessary to understand the basic fossil record of dinosaurs.
University of California Press, Farlow, J. Extinction of Dinosaurs Extinction of Dinosaurs Two-hundred and thirty million years ago the first dinosaur-like creature roamed the earth. Finally The last dinosaurs that walked on the earth died about 65 million years ago.
Following the principles of genealogy that are applied to humans as much as to other organisms, organisms are classified at a higher level within the groups from which they evolved.
From the Morrison site came the original specimens of AllosaurusDiplodocusAtlantosaurus, and Brontosaurus later renamed Apatosaurus. It is equally posited that temperatures will have risen dramatically after the impact and that flaming balls of ejected rock will have created wild fires all around the globe.
Most died out by the end of the Cretaceous Periodabout 66 million years ago, but many lines of evidence now show that one lineage evolved into birds about million years ago.
Lava flooded large areas of India and explosions in the South Atlantic and the Midwestern United States hurled ash over much of the globe.
The fossil evidence shows a moderately rich fauna of plateosaurs and other prosauropods, primitive ornithopodsand theropods during the Late Triassic Epoch million to First, at about the boundary between the Carnian and Norian faunal stages, about million years ago, dicynodonts and a variety of basal archosauromorphs, including the prolacertiforms and rhynchosaurs, became extinct.
The discovery of Kulindadromeus zabaikalicus, an early ornithischian dinosaur whose remains show evidence of featherlike structures on its limbs, suggests that feathers may even have been widespread among the dinosaurs.
Early on it was recognized that, as a group, dinosaurs appear to be most closely allied to crocodiliansthough T. Dinosaurs are often brought up in the media and normal life and are also constantly referenced in relation to other animals and films but not many people actually know what a Dinosaur is.
Harriet Gibson 6 II. Lizards have legs in a squatted position, with the legs going outwards. It is important to note that extinction is a normal, universal occurrence.
EXTINCTION. Two-hundred and thirty million years ago the first dinosaur-like creature roamed the earth. Within five million years it could be considered a dinosaur/5(7). The Cause of the Dinosaur Extinction Essay.
Length: words ( double-spaced pages) Rating: Better Essays. Open Document. Essay Preview. The most popular theory is that an asteroid ended the reign of the dinosaurs. Another theory, massive climate change in the pre-historic atmosphere, caused all the dinosaurs to die.
Essay about Dinosaur Extinction Words | 6 Pages. A number of different theories have been assessed throughout the course of this research to attempt to reach a conclusion as to the reason behind the extinction of the Tyrannosaurus Rex.
The most popular theory of the Catastrophists is the asteroid theory. An asteroid called Chicxulub hit the earth creating a mile wide crater near the Yucatan Peninsula in Mexico. The date this asteroid hit the earth was sometime about million years ago, just about the.
According to them, an asteroid five miles across blasted through the Earth's crust, and threw up molten rock, ash, and dust. Adding to the support to this theory is the discovery of a layer of iridium in New Zealand, Denmark, and Italy.
The last theory for the extinction of dinosaurs is a major climatic change.
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