For the most part, this book makes a fascinating and highly informative read. It details extinct animals from a wide variety of groups and time periods - the dinosaurs in particular are excellently represented, with almost every known species featured. Other animal groups appear in lesser numbers, but well-known pterosaurs, plesiosaurs and prehistoric mammals all make an appearance. In addition, lesser-known extinct animals are included, such as early amphibians and the mammal-like reptiles.
However, there are a few glaring errors which cannot be overlooked. For example, the nimravids are described as cats, when they were in fact a completely separate family (Nimravidae, as opposed to Felidae). Two of the prehistoric whales, Rodhocetus and Basilosaurus, are classified in their information boxes as primates, which is obviously incorrect. One sentence reads: "It has been accepted for some time that the dinosaurs evolved from birds" - clearly the words "dinosaurs" and "birds" are the wrong way round here. There are also spelling errors that one would not expect to see in a scientific book such as this - e.g. yolk spelt "yoke".
The problem here is that, once you notice one mistake, you are left wondering how many others you have missed. The end result is that you cannot rely on the information given as being correct. In an educational book such as this every effort should be made to ensure the accuracy of the facts, otherwise those who buy the book in good faith will end up being misinformed - surely the very opposite of the purpose of this kind of publication.