Endotherms are animals that maintain a constant body temperature no matter what the external temperature is.

The reading passage and the lecture both question if dinosaurs are endotherms or not. Whereas the author of the reading states that dinosaurs are endotherms the instructor suggests otherwise. The professor casts doubt on the points made in the reading for three reasons. Firstly, the reading states that dinosaurs surviving in the polar regions must have maintained a constant body temperature irrespective of the external temperature like the endotherms. Nevertheless, the instructor rebuts this argument by explaining that at those times polar regions were much warmer,and in winter the dinosaurs might have hibernated like other reptiles or might have migrated. Secondly, according to the reading, the position and movement of the legs underneath the body of dinosaurs suggest that they were endotherms. However, the professor disputes this point. He says that although legs were present in dinosaurs' bodies they were not meant for high-energy movements like running as endotherms do, but for providing support to their gigantic body size. In this context, it can be said that dinosaurs did not fall under the category of endotherms. Finally, the reading claims that like endotherms, canals were present in the bone structure of dinosaurs also. Even though, the instructor admits this point he claims that the creatures were not constantly growing, which contradicts the characteristic of the endotherms because the latter shows regular growth and not periodic growth like the dinosaurs. In conclusion, although the reading and the lecture are both about the controversy of whether dinosaurs are endotherms or not, the professor refutes all the three points made in the reading