) After existing for 163 million years, the dinosaurs disappeared at the end of the Cretaceous Period, 66 million years ago. The Earth's appearance during the Mesozoic Era was quite different from its appearance today.The reason for the difference is that although the surface of our Earth seems rock solid, it is not. After existing for 163 million years, the dinosaurs disappeared at the end of the Cretaceous Period, 66 million years ago. The Earth's appearance during the Mesozoic Era was quite different from its appearance today.
When The World Was Black: The Untold History Of The Worldâs First Civilizations, Part One: Prehistoric Cultures (When The World Was Black: The Untold History Of The Worldâs First Civilizations #1) âIn this book, youâll learn about the history of Black people.
A Unipolar World: Systems and Wars in Three Different Military Eras. In 1989 the Berlin Wall fell, the first of a series of events bringing the period known as the Cold War to an end. From a state of military multipolarity (1815-1945), the world had progressed to one of bipolarity (1945-1989), to the current situation of unipolarity.