香蕉视频

Dinosaurs may have roamed and mingled more freely in the western interior of North America than previously thought, according to a new study. For decades, many paleontologists believed that during the Late Cretaceous period, from about 100 million to 65 million years ago, dinosaur species occupied relatively restricted ranges in the West. At the end of this period, Leptoceratops, with its beaked snout and neck frill, inhabited the northern part of the West, the long-necked Alamosaurus resided in the south and the triple-horned Triceratops meandered through the western interior.

鈥淭his didn鈥檛 make any sense to me,鈥� said PhD student Matthew Vavrek of 香蕉视频, coauthor of the study published April 19 in the Proceedings of the National Academy of Sciences. 鈥淟arge animals need more space to survive and reproduce. Why would dinosaurs be unable to colonize the whole continent like mammals do today?鈥� Vavrek and Professor Hans Larsson of 香蕉视频 now report that dinosaur ranges were more extensive than previous estimates suggested.