The Road to Extinction Dinosaurs have captured the whole world’s attention and curiosity. How did they come to be extinct? What factors led to this downfall? Are they completely extinct? All these questions additional to several others have aroused among many scientists. Although the extinction of the dinosaurs was the smallest one it seems to be the most discussed (Meyer, 2016, personal communication). So what was the cause of the end of these grand creatures? In the article “The ‘Great Extinction’ That Never Happened: the demise of the dinosaurs considered”, Sarjeant and Currie discuss various explanations that have risen about the extinction of the dinosaurs and what caused it. Major topics among these are iridium layers, dust clouds, extraterrestrial impact, and drastic changes in climate. It is questioned whether the iridium layer was formed from the extraterrestrial impact or from volcanic activity. If the iridium layer formed due to volcanic activity it would have done so through dust clouds. This theory supports that oxygen levels would have been extremely low which would have suffocated the dinosaurs. Not enough evidence is presented in order to prove if the extinction was owed to the extraterrestrial impact or not. There were also major changes in sea levels and climate changes that more than likely caused environmental stress to the biota and marine biota. Sarjeant and Currie support Birkelund and Haukunsson with the concept that the extinction was caused by numerous events and not solely one (Sarjeant and Currie, 2001). Gould defines three popular explanations as to why the dinosaurs became extinct but he proceeds to describe why they may be flawed. One theory suggested that dinosaurs went extinct due to the high temperatures that arose during the Cretaceous period. Testes are external because they would not function well with the high internal temperatures of their bodies which understandably led to the theory of sterilization of the male dinosaurs attributable to the high external temperatures. Had that certainly taken place, there would no longer be any future generations. Another theory thought to have been a cause of the elimination of these creatures was the overdose of angiosperms which came about towards the end of the dinosaurs’ time. They contained high amounts of chemicals avoided by most mammals. Some believe that dinosaurs did not possess what was needed in order to distinguish the bitter taste of the plants or the organs to break the chemicals down. An overdose is the result of what this theory claims. Lastly, Gould presents the final notion that might have contributed to this extinction which is one that Sarjeant and Currie discussed as well. An asteroid or comet must have hit the earth which then caused a dust cloud to form. This dust cloud covered the sun
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Since the only trace of iridium is near the impact location it seems that it would have affected the immediate area solely, therefore it would not be enough to eliminate the entire species across the earth. There must be additional causes. A combination of temperature fluctuations, competition between species, scarce resources for any of the reasons discussed, along with many other factors must have contributed to the slow declination of this species. Yet, there is not enough evidence to conclude a concrete answer leaving scientists to continue asking and
Since the only trace of iridium is near the impact location it seems that it would have affected the immediate area solely, therefore it would not be enough to eliminate the entire species across the earth. There must be additional causes. A combination of temperature fluctuations, competition between species, scarce resources for any of the reasons discussed, along with many other factors must have contributed to the slow declination of this species. Yet, there is not enough evidence to conclude a concrete answer leaving scientists to continue asking and