Artwork of a dinosaur, Tyrannosaurus, hunting in a forest. Dinosaurs were reptiles that dominated life on land for 140 million years throughout the Mesozoic era: from the late Triassic period until the end of the Cretaceous period 64 million years ago. Over 800 species are known which are divided into two groups: the reptile-hipped and the bird- hipped dinosaurs. The Tyrannosaurus species belongs to the first group and includes the largest carnivorous, two-legged dinosaurs which reached 12m in length. Dinosaurs became suddenly extinct probably due to strong climatic changes and the competition from mammals in the changing environment.
Model release not required. Property release not required.