Extinction Of Dinosaurs Essay -- essays research papers

Extinction of Dinosaurs     Two-hundred and thirty million years past the first dinosaur-likecreature roamed the earth. Within five million years it could be considered adinosaur. They were soon at the top of the food chain. They populated all(prenominal)continent. Then 65 million years ago they vanished. The most brawnycreatures ever to live on earth had become extinct.     Dinosaurs were not the tho victims of this "mass defunctness." Therewere many other species that were killed off. During what is known as the K-Textinction (K stands for Cretaceous, T stands for Tertiary), many species andfamilies became extinct. These include all marine reptiles such as plesiosaurs,mosasaurs, ichthyosaurs, and ammonites, swimming and flying reptiles, seacrocodiles, and foraminifera. In addition to that there were many bony fish,sponges, snails, clams, and sea urchins became extinct.     Paleontologists have proposed scenar ios that could have caused theseextinctions. One such scenario involves the growth number of small mammalswhich ate dinosaur eggs, and therefore caused the dinosaurs kind rate to drop.The birth rate became smaller than the death rate and the dinosaurs died out.This, however, is not a plausible scenario. This would only account for thedinosaurs, but not all the other creatures of that time. Paleontologists postulateto come up with a more plausible and de...