TPO4 TASK 1

The professor discusses some problems that scientists have with the idea of considering dinosaurs as endotherm. These lecture is in direct opposition with the presented facts in the reading passage.

First, the lecturer asserts the discovery of dinosaurs fossils can't prove the fact that they were endotherms. In fact, she points out polar regions were warmer at that time comparing with today and the temperature was high enough for animals to live even they who weren't endotherm. Moreover, she states that dinosaurs could migrate on cold seasons to warmer areas and then came back to that region again when the weather was fine. Meanwhile, they could hibernate on cold climates to survive like what other animals did. On the other hand, the reading passage elaborates dinosaurs could maintain a body temperature higher than their environment so they are endotherms.

Second, the professor makes it clear that the position of their legs doesn't prove considering them as endotherms and there is another explanation for this. Indeed, she illustrates their legs were under their bodies instead of being beside their bodies like crocodiles. She, demonstrates this position can support more weight and in this way they could grow to very large sizes and by this they had some advantages over other contemporary animals. Conversely, the reading passage claims the position of their legs suggests they are endotherms.

Third, she mentions although their bone's structure had Haversian canals they had growth rings as well. The evidence of growth rings in their bodies means they didn't grow continuously and there were some gaps in their growth process. She describes endotherms grow rapidly in all seasons and their growth doesn't cease on cold seasons. But the existence of growth rings in their bodies picturesquely indicates their growth was stopped or at least was slower on cold climates so they can't be endotherms. However, the presented facts in the reading passage specifies the evidence of Haversian canals in their bodies boosts the idea of considering them as endotherms.