TOEFL integrated writing: Endotherms

The reading states that the dinosaurs would be an endothermic animals, which can maintain their body temperature constantly regardless, of the environmental temperature change exactly like humans and other mammals.The passage provides various reasons to support. However, the lecture doesn't agree with this and casts doubts about the points that the reading had mentioned.

Firstly, the reading states that the dinosaur fossils at polar region indicates that the dinosaurs had an ability to maintain their body temperature constantly like a man in cold climates, which is the characteristic feature of endothermic animals.However, the lecture argues about this point and says that the weather at polar region at that time was warmer than today.So, it would be possible for the animals to survive in that region when they are not endotherms. Then, when the weather started to be colder, the dinosaur would migrate to the regions that are warmer or hibernate by using various modern techniques.

Secondly, the reading mentions that the dinosaur had another important feature that was having legs under the body, not on side ways of the body like other modern reptiles like crocodiles. AS the dinosaurs need heavy energy to run and have active movements in order to keep their body warm this was very helpful. In contrast , the lecture opposes this statement because the dinosaurs were gigantic creatures, so they had their legs under their body in order to support their weight and not for running.

Finally, the reading states that the dinosaurs had Haversian canals in their bones, which was one of the important characteristic feature of endotherms. In contrariety, the speaker argues that the dinosaurs had Haversian canal along with growth rings. These growth rings are thickening of bones when the dinosaurs were rapidly growing.They are evident. These growth rings show rapid growth followed by no growth to slow growth.This indicates that the dinosaurs did not grow rapidly and constantly as other endotherms. So, these all reasons indicates that the dinosaurs were not endothermic animals.