TPO 39 Integrated Essay Extinction event

The reading and the lecture are both about a mass extinction event at the end of the Triassic period. The author of the reading presents three possible explanations for this phenomenon. The lecturer casts doubt on the claims made in the article. She thinks that none of the theories are supported by facts or evidence.
First of all, the author claims that declining sea levels led to this mass extinction event. The passage notes that many animal populations that lived there were affected by sea level change. This point is challenged by the lecturer. She says that gradual changes would allow the animals to adapt. She points out that the change took place over millions of years and this would give the creatures enough time to evolve and survive.
Secondly, the author states that massive cooling could have killed these animals. The paragraph argues that volcanic activity released a lot of SO2 which contributed to this cooling. This argument is rebutted by the lecturer. She suggests that SO2 can cause a drop in temperature, but it doesn’t stay in the atmosphere very long, only a few years. She notes that this chemical combines with water and comes down as rain.
Finally, the author mentions that an asteroid hitting the earth's surface caused mass extinction. He is of the opinion that this asteroid strike caused large amounts of soil and crushed rock, which were thrown up into the atmosphere where it can block out sunlight. In contrast, the lecturer's stance is that the researchers couldn't find any asteroid crater dated to the time when the mass distinction occurred. She puts forth the idea that the crater they found was dated to about 12 million years before the extinction. That's just too long before the extinction.