The word dinosaur is derived from the Greek term deino’s which fearful or terrible and sauro’s means lizards or the reptiles. Dinosaur have been believed to be existed on Earth before 65 million years ago. The dinosaurs ruled the Earth for millions of years. Scientists beleive that the dinosaurs were vanished in a massive asteroid impact on Earth millions of years ago causing climatic changes, erupting volcanoes, choking chemical gases and other possible factors.
Dinosaurs existed on Earth in different sizes
The Dinosaurs existed on Earth in different sizes and shapes. There lived gaingantic ones to the flying ones and the ones size of a turkey. The largest dionsaurs were Argentinosaurs, seismosaurs, ultrasaurs, brachiosaurs and the supersaurs. The smallest dinosaurs was the Compsognathus. Plant eating sauropods were the hugest animals to walk on Earth. There was only one continent on the Earth when the dinosaurs existed.
Dinorsaurs are classified into two types
The scientist classified dinosaurs into two types based on their bone structures. They are the Saurischians and Ornithischians. Dinosaur fossils have been discovered in all the continents. Some of the animals moved very faster and some moved very slowly due to their heavy bodies. There were carnivorous and herbivorous dinosaurs. Scientists beleave that birds were descended from a type of dinosaurs called theropods.