TOEFL Integrated Writing Practice Test 037Dinosaur Fossils

Numerous dinosaur fossils have been discovered in Alaska’s North Slope, an area now known for its frigid Arctic climate. Around 100 million years ago, when dinosaurs roamed this region, the environment was already quite harsh, especially in winter when months of total darkness occurred. How these dinosaurs, particularly the large herbivorous edmontosaur (Edmontosaurus), managed to survive the extreme winter conditions has led paleontologists to propose the idea that they survived by migrating south to more hospitable climates. Several points support this migration hypothesis.

First, the edmontosaur’s diet lends credence to the migration theory. Edmontosaurs were herbivores, relying entirely on plants for food. Since no plants could grow during the prolonged cold and darkness of the North Slope winter, it seems logical that these dinosaurs would have had to leave the region to find food in more temperate areas.

Second, the discovery of many edmontosaur skeletons at the same site suggests they lived in herds. Modern migratory animals, like caribou and buffalo, also live in herds and travel together during migrations. Living in herds allows animals to coordinate their movements, which is another indication that edmontosaurs may have migrated in large groups.

Lastly, edmontosaurs were physically well-suited for long-distance travel. To escape the harsh winter, they would need to migrate approximately 1,600 kilometers south. At a pace of five kilometers per hour, a migration could be accomplished within several weeks. Given that edmontosaurs were capable of running up to 45 kilometers per hour, their physical abilities suggest they could easily have completed the journey to a warmer climate during the harsh Arctic winters.