Dinosaur origami, a beautiful illustrated tutorial on hand-made origami of dinosaurs. Dinosaurs are a type of reptiles from the Mesozoic Era (230 million years ago). Their strong limbs, long tails and huge bodies are the characteristics of most dinosaurs. Portrait. Dinosaurs suddenly disappeared at the end of the Cretaceous period 65 million years ago, becoming a mystery in the history of biological evolution on earth. This mystery is still unsolved by no one.