TOEFL integrated writing Endotherms

The reading states that dinosaurs would be considered as endotherm animals, which can maintain body temperature constantly regardless the environment temperature change, and presents several reasons to support. However, the lecture doesn’t agree and cast doubt the points that the reading mentions.

First, the reading states that discovering dinosaur fossils at the polar region indicates that the dinosaurs had ability to maintain their body temperature constantly in cold climates, which is the characteristic of endotherm animals. However, the lecture argues this points and says that actually the weather at polar regions at that time were warmer than today. So, it would possible that animals that were not endotherms could survive at that region. Then, when the weather started to be colder, the dinosaur migrated to the regions that were warmer.

Second, the reading mentions that the dinosaurs had another endotherm characteristics, which was having legs under their body,not on side way of the body like other modern reptiles. This helped the dinosaurs to run and had active activities in order to keep their body warm. In contrast, the lecture opposes that because the dinosaurs were huge , so they had the legs under their body in order to support their weight , not for running. Also,having large body had some advantages.

Finally , the reading says that the dinosaurs had Haversian canals in thier bones, which was one of the endotherm characteristics. On the other hand, the speaker argues that the dinosaurs had both Haversain canal and growth rings. The growth rings showed rapid growth along with slow growth. This indicates that the dinosaurs did not growth rapidly and constantly all the time as endotherm characteristics. So, dinosaurs are not endotherm animals.