dinosaurs endotherm

The reading states that dinosaurs were endotherm animals and provides three reasons of support. However, the speaker explains that scientists believe these arguments are unlikely true and refutes each of the author’s claims. First, the article claims that dinosaurs' fossils have been discovered in Polar Regions which suggest dinosaurs belong to this category since endotherms are the only ones suitable to maintain and survive temperatures in cold climates. The professor refutes this point by saying that those regions were warmer years ago than nowadays. Moreover, although such great temperatures were reached, dinosaurs could have migrated or hibernated from this temperature. Hence, the fossils found do not prove this animal was endotherm. Second, the article posits that because dinosaurs had leg located under the body, they were endotherms. Furthermore, the leg position has allowed them to sustain physical activity, such as running. The author states that today, endotherm animals present legs underneath as dinosaurs at that time. However, the professor explains that dinosaurs were not endotherms even though the legs were under the body. Moreover, he mentions that the most reasonable explanation is that they needed to grow to large size in order to support their weight. Thus, dinosaurs cannot be categorized as endotherm. Third, the article says that dinosaur presented harversian structures inside the bones which suggest that they grew quickly as endotherm animals do. The professor opposes to this point by saying that they also had some structures are called growth rings that indicate dinosaurs grew and stopped growing in some periods. This disrupted pattern is characteristic of non endotherm animals, so dinosaurs were not endotherm as the reading exposed.