There must have been a first time in the distant human past, some thousands of years ago, when someone stumbled across the bones of a large but unknown creature. This amazed person must have reasoned that there are large and terrifying animals in the world. And so, legends of dragons entered the story telling tradition of our species. Once this tale of gigantic ferocious beasts was told, our busy imagination led us to believe we must sometime meet the monsters face to face. So, stories of encounters with wild animals would grow and spread to become vivid sagas of battles between dragons and people.

It took many centuries for human beings to grasp the real story, that these monsters existed not in the present but hundreds of millions of years in the past, when the ancestors of people were still tiny and mouse-like. It is only in the last two centuries that we have been seriously searching for and studying the remains of the real dragons, the dinosaurs.

By now we have dug many bones out of the ground, measured, compared and reassembled what has been found and have been amazed by the startling array of long extinct giants. There are known so far over 700 kinds of dinosaur and as many giant extinct mammals unlike anything alive today. In all likelihood, many hundreds or thousands more remain to be discovered. The bones have told us that certain groups of reptiles must have been the ancestors of mammals. These books attempt to show this transition from reptiles, taking place alongside the dinosaurs, to a new kind of warm blooded animal who would survive the catastrophe that ended the big reptiles and eventually  produced many new mammal giants that then also passed into extinction.

Any coloring book that takes on this huge and growing area of knowledge must of course only scratch the surface. But we hope the young colorers who amuse themselves with these pictures of a few well known dinosaurs and early mammals will have a window open on the world of the past and get a little greater appreciation and understanding of the origins and evolution of life on Earth