Dinosaurs are much cooler than mammals because they are so much bigger. T. rex could eat a tiger, easy.

Saurischians include the sauropods (the biggest of all dinosaurs) and the theropods (the carnivorous dinosaurs).

Ornithischians include Triceratops, Pachycephalosaurus, Stegosaurus, Ankylosaurus and Iguanodon.

The coolest dinosaurs of all were the sauropods. They were way huge. I mean, you may think it's a long way from the top of a giraffe to the bottom, but that's peanuts to a Brachiosaurus. The coolest sauropods of all were: Bruhathkayosaurus Amphicoelias fragillimus Brachiosaurus, which has the species: altithorax brancai ?nougaredi Sauroposeidon Migeod's mysterious M23 sauropod