2, At the end of the Cretaceous, the geological record shows that these seaways retreated from the continents back into the major ocean basins. no one knows why. Over a period of about 100,000 years, while the seas pulled back, climates around the world became dramatically more extreme: warmer days, cooler nights; hotter summers, colder winters. Perhaps dinosaurs could not tolerate these extreme temperature changes and became extinct.
3, If true, though, why did cold-blooded animals such as snakes, lizards, turtles, and crocodiles survive the freezing winters and torrid summers? These animals are at the mercy of the climate to maintain a livable body temperature. It’s hard to understand why they would not be affected, whereas dinosaurs were left too crippled to cope, especially if, as some scientists believe, dinosaurs were warm-blooded. Critics also point out that the shallow seaways had retreated from and advanced on the continents numerous times during the Mesozoic, so why did the dinosaurs survive the climatic changes associated with the earlier fluctuations but not with this one? Although initially appealing, the hypothesis of a simple climatic change related to sea levels is insufficient to explain all the data.
Why does the author mention the survival of “snakes, lizards, turtles, and crocodiles” in paragraph 3?
A. To argue that dinosaurs may have become extinct because they were not cold-blooded animals
B. To question the adequacy of the hypothesis that climatic change related to sea levels caused the extinction of the dinosaurs
C. To present examples of animals that could maintain a livable body temperature more easily than dinosaurs
D. To support a hypothesis that these animals were not as sensitive to climate changes in the Cretaceous period as they are today
Saori T.
12/06/13