Edmontoosaurs Migrate

The passage thinks that edmontoosaurs migrated south to survive the winter. Meanwhile, the pofesser says that they didn't migrate. First of all, the author states that this kind of dinosaur mainly ate plants which could not live during winter, so they have to migrate to find food. But the lectrue argues that it was warmer at that time. There was 24 hours of sunlight during summer, so there were many plants. In winter, there were many dead plants containing many nutritions which could be eaten by this kind of dinosaur, so that they did not have to move to warmer places. In addition, the passage says that edmotosaur skeletons show that they lived in herd, which helps animals coordinate their migration. But the pofesser does not think so.