TOEFL Sample essay : integrated essay from TPO4

In these set of material, both the passage and the professor are talking about if the Dinosaurs were endotherms or not. The reading states that, dinosaurs differ in many ways from modern reptiles , and there is now considerable evidence that dinosaurs were , in fact, endotherms. Conversely the speaker says that, many scientists disapproved that, in addition, all the reasons that mentioned in the passage are unconvincing.

First, the reading states that, one reason for believing that dinosaurs were endotherms is that dinosaur fossils have been discovered in polar regions. However the professor says that, the polar regions were much warmer than today, the animal could live there in the past, furthermore, they couldn't move to warmer areas, that's why they had remained in the polar areas. This directly contradicts what the passage indicates.

Second, the reading argues that, there is a connection between endothermy and the position and the movement of the legs. And the legs of modern endotherms are underneath the body, and so were the legs of dinosaur. But the speaker says that, this position of the dinosaurs' legs because they had need high energy for running, thus the body should support more weight. Thus the position of the legs give advantages to dinosaurs. This was another place where experience contradicted theory.

Third, the reading claims that, the bones of endotherm usually include structures called Haversian canals. And so were in the bones of dinosaurs and this suggests that the dinosaurs were endotherms. But the professor says that, this is right , but the dinosaur also have thickened rings in their bones allow them to grow quickly. So these rings were evidence for the growth rates, in addition these rings don't approve that the dinosaur are endotherms, because there are growing quickly even if the environment came cool.