What Happened To The Dinosaurs?? Dinosaurs freely roamed the Earth during the Mesozoic Era (The Age of the Dinosaurs) more than 150 million years ago. Fossils have proved that the dinosaurs roamed many different parts of the Earth at the same time. They survived for hundreds of millions of years on the Earth. One of the great mysteries of the dinosaurs surrounds their extinction. Most dinosaurs finally became extinct about 65 million years ago during the Late Cretaceous period. There have been various theories which have attempted to explain the mystery of their extinction. Some scientists argue over the term and actual concept of the extinction of the dinosaur. There is some debate over the use of the term 'extinction of dinosaurs' as birds are dinosaurs and have survived the apparent extinction to become a vital and prominent species in modern-day society. Older scientists theorized that dinosaurs died out and became extinct because they evolved "'too much" - that is, they became too big and specialized and were unable to adapt to a ever-changing world. But, this theory is inaccurate and unscientific. Dinosaurs were well adapted to their earthly surroundings. They were not unusually stupid and they flourished for more than 150 million years (Gaffney, Dinosaurs, page 148). Another theory centers around the extra-terrestrial causes for the extinction of the dinosaurs. Some believe large meteorite impacts produced great dust clouds causing mass extinction. This theory is flawed. How did birds survive and flourish during this dark phase in our planet's history? Other evidence proves; some dinosaurs actually became extinct before 65 million years ago. This meant some dinosaurs became extinct years before the supposed large meteorite impacts that caused the mass extinction of dinosaurs (Gaffney, Dinosaurs, page 148). The last theory about possible causes of the extinction of the dinosaurs is more plausible than any of the other theories which I haveresearched. This theory utilizes the climatic change of the Earth as a reason for the extinction of the dinosaurs. There is extensive geologic and paleontologic evidence of a great climatic change in the Late Cretaceous and Early Tertiary periods. The climate became quite colder than it had been for many years. The seasons became more extreme. Large bodies of water covering a great portion of the continents drained away. This change and the apparent draining of the seas that covered North America could have actually caused the disorientation, dislocation and extinction of many living things including other types of animals? that roamed the Earth during this period. Dinosaurs were cold-blooded and scientists theorize their bodies could not adapt to the sudden climatic change of the Earth. Other scientists built on this theory by adding that a drought (caused by drainage of large bodies of water) could have contributed to the demise of the dinosaurs (except the birds who could travel greater distances in search of water). The sub-tropic existence of the land during the Cretaceous period was replaced by the more temperate forests of the Early Tertiary during this climatic change which many believe contributed to the extinction of the dinosaurs (Gaffney, Dinosaurs, page 148). I believe that the theory which explains why the dinosaurs became extinct is the climactic change theory. The Earth has a history to tell through many different "voices" (i.e. age of the Earth's rocks). Scientists have listened to these voices (some more than others). The climatic change theory explains why some dinosaurs were not able to survive and others (i.e. birds) were able to survive. There needs to be more investigation into the history of the climatic change theory because I believe it is the most scientific Bibliography Gaffney, E. Dinosaurs. Golden Press: New York, 1990
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