It seems stranger than fiction�but it�s true: this astonishing array of fascinating creatures really did inhabit the earth eons before humans ever existed. But they have come alive once again on these vivid pages to amaze kids. Youngsters can see what emerged and when, beginning with single-celled life forms more than 3,500 million years ago. There�s plenty of engrossing detail on the development of life in the sea, land, and air; on invertebrates, fish, amphibians, early tetrapods, reptiles, birds, and, finally, on mammals and other prehistoric beings. Each creature�including dinosaurs, of course�gets a full, information-packed spread, along with drawings to show what it probably looked like, an illustration of a known animal for comparison, and a time line.