简介：As dinosaurs grew into the behemoths of the Cretaceous period they evolved many extraordinary but apparently useless features including spikes, sails horns, crests and the tiny arms of tyrannosaurs. The program reviews these unusual feature..
As dinosaurs grew into the behemoths of the Cretaceous period they evolved many extraordinary but apparently useless features including spikes, sails horns, crests and the tiny arms of tyrannosaurs. The program reviews these unusual features and discusses theories of why they exist.展开