TPO4

In this set of materials, the reading passage and the lecture both discuss on the issue whether or not the dinosaurs are endotherms. As dinosaurs differ from the modern reptiles, the reading passage supports the idea of being endothermic of dinosaur according to three evidences. While, professor in the lecture, opposes with that claim and refutes all three reasons mentioned in the reading passage.

First, based on the article, some fossils of dinosaurs have been found in the Polar Regions which mean they could keep the body's temperature at that time. However, in the lecture, the speaker rejects the reason by explaining about the ways that dinosaurs could keep themselves away from the cold weather. She cites that, in the past, Polar Regions were warm in some parts of the year, they could migrate to warmer places in cold seasons, or they could hibernate like the other reptiles.

Second, in the reading passage, having legs underneath the body is considered an evidence of the idea that dinosaurs are endotherms. While, the professor controverts the idea by declaring some possible reasons for being the legs under the body rather than beside the body. She holds forth that they needed the legs for having high energy to run fast. In addition, it let them support their heavy weight and large body.

Finally, In the article, Haversian Canal in the bone structure of dinosaurs is an evidence of being endothermic. On the other hand, professor supporting the canal in the dinosaur’s bone talks about the growth ring. The ring proves that the dinosaurs in which period of time had fast growth and when they had a slow growth. So, this ring showed that the dinosaurs had had no growth or slow growth in the cold weather which can be a reason that they were undothermic.