The authors of this book were perhaps a little presumptuous when giving it a title - it goes without saying that this slim volume is hardly the "complete" guide to prehistoric life. It does, however, feature almost all the creatures that appeared in the B.B.C. series 'Walking With Monsters', 'Walking With Dinosaurs' and 'Walking With Beasts', as well as additional species.
For the most part, the computer-generated images of the animals are excellent (though the cave lion is incorrectly proportioned, being depicted with a short tail when it was, in fact, identical to modern lions except for being larger and would therefore have had a long tail).
Unfortunately, though the majority of the information given is correct, there are an unacceptable number of mistakes in the text. Many are simple schoolboy errors, such as using the word ancestor in place of descendant, or stating that "artiodactyl" means "odd-toed" when in fact it means "even-toed". Some may even be typographical errors - for example, it is stated that Smilodon became extinct 100,000 years ago, when it actually became extinct only 10,000 years ago. In either case, these should have been picked up at the editing stage and should not have made it into final print.
What I found more irritating was the apparently deliberate mistranslation of the word "saurus" (which means "lizard") as "reptile" in the case of almost every creature with this as part of its name. Anyone with even a passing interest in palaeontology knows that the name of the famous Tyrannosaurus translates as "tyrant lizard" - here, however, it is translated as "terrible reptile". Whilst it is true that many of these animals were named when dinosaurs were believed to be cold-blooded, lizard-like creatures, one cannot simply change the meaning of the word to reflect our new knowledge.
It is one thing to overlook facts here and there in a work of fiction, but in a supposedly educational reference book I feel every effort should be made to ensure the accuracy of the information, else what is the point? In short, if you buy this book, do so only for the handsome reconstructions of the animals - as an accurate source of knowledge, it should not be relied upon.