TPO 39 Integrated Task

In this given set of materials, the main topic is centered on possible explanations regarding the mass extinction at the end of Triassic period, which contributed to the dominance of dinosaurs afterwards. While the writer puts forward three possible explanations as cited in the passage, the professor disagrees and claims that none of them is good enough whereas they seem reasonable.

To begin with, first possible explanation according to the passage is disruption of food chains which might have been resulted from destruction of coastal and shallow-ocean species due to fluctuation of sea levels near the end of the Triassic period. However, the professor refutes this reason by stating that these species had the ability to adapt to changes. Also, she notes that fluctuations in sea levels happened gradually, therein coastal species had time to adapt. So, the change must be rapid to lead to extinction.

Second, the writer mentions that SO2, which had been released from volcanoes activity, might have lowered global temperatures, hence, leading to massive extinction. Yet again, the professor disagrees and notes that SO2 is still present in atmosphere, but, the global temperature does not seem to be lower. Therefore, SO2 must not have been in the atmosphere long enough to have an impact on extinction.

Last but not least, the professor rejects the third possible explanation mentioned in the passage, blocked sunlight resulted from an impact of massive asteroid which created debris, by mentioning that scientists did not find any evidence of such asteroid or crater, depression left behind by the asteroid due to the impact. Although they found some evidence but it was for 12 years before the extinction. Hence, this explanation is unlikely to be the reason for massive extinction.