This book about paleontology is the only science that can show who the ancestors of different creatures inhabiting today's Earth were. Until recently, we did not even suspect that whales breed from artiodactyls, birds from dinosaurs, and beetles and spiders - of course, through many intermediate stages - from worms with a proboscis and claws on soft legs. Yes, molecular biology can explain who is related and prove that birds are closer to crocodiles than to turtles, and whales are closer to hippos than to bears. But what did these poultry models or whalebumps look like? All living things were constantly changing, all organisms were actually transitional forms and, it turns out, looked completely different than one might assume when studying the modern natural world. It is impossible to cover all these forms in one book, but let's try to talk about the most interesting ones.