What if elephants were as small as dogs? What if frogs were protected by armor? In prehistoric times, they were! In fact, other than a few unique changes, lots of prehistoric beasts looked similar to modern animals that live on Earth. Hedgehogs had long tails and no quills, some birds laid eggs the size of footballs, and dragonflies could eat reptiles and amphibians! If these extinct beasts came to life, they might look familiar--but you wouldn't want to get in their way! Read this book to learn more about the incredible and terrifying prehistoric ancestors of modern animals.