Endotherms are animals such as modern birds and mammals that keep their body temperatures constant For instance humans are endotherms and maintain an internal temperature of 37 C no matter whether the environment is warm or cold Because dinosaurs were rep

The reading and the listening don’t concur with the concept whether dinosaurs were endotherms due to several evidences.

First of all, the reading passage indicates that fossils of dinosaurs found in polar region can prove that dinosaurs were endotherms because only endotherms can be active in there. However, the speaker claims that polar region at that time was warmer than today. Moreover, even when the climate is too cool for dinosaurs to live in, they might migrate to other places which were warmer or they could hibernate while winter.

Secondly, contrary to the belief in the reading that endothermy allows running efficiently only if legs are positioned under body, so dinosaurs whose legs were below their bodies were regard as endotherms, the speaker argues that dinosaurs’ legs were underneath their bodies because they need to support their heavy weight. As a result, dinosaurs’ legs below their bodies were not a characteristic of endotherms but for a good support of bodies.

Lastly, from the reading, endotherms usually include Haversian canals which allow animal grow up rapidly, so do dinosaurs. Yet, the speaker indicates that dinosaurs’ growth rings weren’t a characteristic of endotherms. To be precise, it is true that dinosaurs will grow quickly while the weather is warm but they will grow slowly or even stop growing when the weather get cold. As a result, dinosaurs were not endotherms due to the growing pattern.