back to Grade 6+ Dinosaurs by: Lauren V., Grade: 6+ Millions of years ago dinosaurs walked the earth. There were many different types of dinosaurs.Tryceirotops, brontosauruus,tyredactyles, and of course,T-Rex They ate many different kinds of foods including plants, meats, and other dinosaurs.hey came in different shapes and sizes too. some were only a few inches to a foot tall,but others were up to 30 or 40 feet long back to Grade 6+