Both the reading and listening discuss whether dinosaurs were endotherms or not. The author believes that they were endotherms unlike modern reptiles, and provides three reasons for support. The lecturer challenges the claims made by the author. She is of the opinion that none of these reasons are correct.
To begin with, the author suggests that dinosaurs were endotherms since their fossils were found in the polar region, which means that they were able to control their body temperature in the extreme cold weather. As a result, they were endotherms. This specific argument is challenged by the lecturer. She says that the polar region at that time was warmer than today, which enabled even the non endotherms to live there. Moreover, the polar dinosaurs lived there when the climate was suitable, and once the cold weather started, they could hibernate or migrate to other areas. Thus, the presence of polar dinosaurs fossils does not prove that they were endotherms.
Secondly, the writer argues that the dinosaur's legs were placed under their body that allow them to do physical activities like running. The article mentions that their leg position indicates that they were endotherms. The lecturer, however, rebuts this claim by asserting that their leg position main function is to support their body weight and they could grow to very large sizes. Hence, this claim is not plausible.
Finally, the author posits that the fossils of dinosaurs bone structures contained Haversian canals, which is the indicator of rapid growth in endotherms. The lecturer, in contrast, casts doubt on this point by explaining that their bones contained growth rings in addition to the Haversian Canal. These rings represent the period of time when they did not grow rapidly in a cold climate, and this pattern of growth supports that they were not endotherms at all.