Dinosaurs are a diverse group of animals of the clade Dinosauria. They first appeared during the Triassic period, 231.4 million years ago, and were the dominant terrestrial vertebrates for 135 million years.
here is two weird facts about Dinosaurs :-
1- The smallest known dinosaur was about four inches tall and weighed less than a chihuahua.
2- The amount of water on Earth is constant, and continually recycled over time: some of the water you drink will have passed through a dinosaur.