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

The article states that there are considerable evidence that dinosaurs were endotherms animals and provides three reasons of support. However, the professor explains that many scientists have problem with the arguments made in the passage and refutes each of the Author’s reasons.

First, the reading claims that dinosaur fossils have been discovered in polar region and this would prove that it was an endotherm to survive there. The professor opposes this point by mention that at old days the polar region was not cold as today, it was much warmer. According to the professor the polar dinosaurs were lived there when the weather is cool and when it changed, they just hybridized or move to another region with less cold.

Second, the article asserts that the position of the leg in dinosaurs are the same as the position of the leg in endotherm animals, and that support the idea of an endotherm dinosaurs. On the other hand, the professor contends that it is true that the dinosaurs have their legs under their body as the other endotherms, but it doesn’t prove that the dinosaur was an endotherm also. She adds that the position of the leg was essential for the dinosaurs to carry their heavy weight.

Third, the article claims that the dinosaurs have a bone structure called haversian canals, which is exist on isotherm's animals. The professor refutes this point by saying that the dinosaurs have the growth rings also. According to the professor, these rings means that the dinosaurs stopped growing in cold weather, not like the endotherm animals which grow constantly in different weather. She adds that the dinosaurs grow only in warm weather and stopped growing on cold weather as the growth rings show on their bones. This disputes the information made in the passage.