S1, E4: Take a first look at how paleontologists categorize dinosaurs. Focusing on the major Saurischia group, identify the dinosaurs of the subgroup Theropoda, including carnivorous predators such as Tyrannosaurus rex and feathered dinosaurs. Continue with subgroups Prosauropoda, a diverse group of herbivores, and Sauropoda, containing the giant, long-necked herbivores such as the iconic Apatosaurus.