Dinosaur Extinction

For over 150 million years, dinosaurs dominated Earth. They were incredibly successful-so successful in fact that all of the other animal groups had no choice but to play a secondary role in nature. 65 million years ago, however, every species of dinosaur went extinct as well mosasaurs, plesiosaurs, pterosaurs, ammonites, and many families of brachiopods and sea sponges. Also, many shark species as well as most vegetation did not survive(“Dinosaur Extinction”). What could have possibly killed off the dominant animal group of the time? The answer to this question is still unclear but there are many hypotheses that attempt to explain this extinction event. To find out exactly how this happened, evidence must be gathered not only from fossils