Cambrian Period, the first geologic period of the Paleozoic Era. It began 570,000,000 years ago and lasted 70,000,000 years. It is named for Wales (which the Romans called Cambria), where sedimentary rocks of the period were first recognized.
Ever since its discovery in 2000, a dinosaur fossil named Leonardo has held the interest of paleontologists the world over. A 3-D model of the animal even toured the world. So what's the big deal?
Emperor Qin ordered 7,000 generals, cavalrymen and archers to protect his mausoleum. What's so odd about that? Well, they were made of terracotta.