How many dinosaurs is there in the world?

There are millions of dinosaurs left in the world. They are called birds. There are none of the four legged terrestrial type pictured in the text books, such as T-Rex. They were all killed about 65 million years ago. Only animals weighing less than a few pounds survived the great extinction. Dinosaurs, except for birds, all weighed too much. It is hard to believe how small our ancestors were.