1 In recent years, scientists have been more concerned with the earth colliding with comets and asteroids and comet Swift-Tuttle is big, about the same size as the asteroid that wiped out dinosaur sixty-five million years ago.
2 We can only guess how fast a dinosaur might have run.
3 We can examine the bones of dinosaurs and make deductions about how they lived.
4 The most distinctive feature of the dinosaurs was their size.
5 While excavating the site for a new hotel, workers unearthed the remains of several dinosaurs.
6 Children are fascinated by the idea of gigantic beasts called dinosaurs roaming the earth before humans even existed.
7 They also have a feature known as an elongated crest that anchored the upper arm muscles, a feature unique to dinosaurs.