TO say that Robert Sabuda makes pop-up books is a bit like saying Michelangelo painted ceilings or that Eiffel made towers - the bare facts do not do justice to the individual skill and creative verve involved. To use the correct terminology, Sabuda is a "paper engineer", which is to say that he is one of a very small band of people designing and creating pop-up books.

There are only around 40 people on the planet who do this, and each book has to be made by hand, usually on assembly lines in South America or Asia. These days Sabuda, a gay American 40-something who works out of a Manhattan studio with his partner Matthew Reinhart, sells about 500,000 copies of each of his titles.

Sabuda started to create his own pop-up books while still a child. His first professional work was The Christmas Alphabet, published in 1994. Since then he has created versions ofThe12DaysOfChristmas,Alice's AdventuresInWonderlandandThe Wonderful Wizard Of Oz, that last being widely considered his greatest creation.

Since 2005 Sabuda and Reinhart have been working on the Encyclopedia Prehistorica, afactualtrilogyexploringlifeinthe prehistoric age. The first two books covered dinosaurs, then sharks and sea monsters. Now Encyclopedia Prehistorica: Megabeasts deals with ancient mammals.It is an extraordinary work - dense, rich and satisfying. There are six spreads, each ofwhichisdominatedbyadifferent pop-up image, all of them colourful and dramatic. In the first, a quetzalocoatlus - "named for the serpentine sky-god of the Aztecs"-spreadsitswings;opening and closing the pages creates a pleasing flapping motion.

These six main images have a considerable wow factor. However, what gives Megabeasts staying power is that each spread also contains several smaller pop-ups concealed within flaps. So, for instance, hidden within the spread dominated by a fierce mammoth there is also a woolly rhino, a wolf and smilodon fighting over a carcass, a giant beaver, a giant deer, a baby mammoth being discovered by miners, and a cave man painting animals. The pictures are terrifically eloquent and even children who cannot read the text will understand much of what is going on. Megabeasts is aimed at ages five and up, but a careful child of around three will also get a great deal out of the book, if properly supervised.

Pop-up books have been around since the 13th century. Originally they were used for astrological calculations and to predict the future, then later they formed part of anatomical textbooks - lift the flap and you could see what lay within the body. It wasn't until the late 1920s that they were designed to delight children.

In the 21st century, the age of iPods and the Nintendo Wii, Sabuda's pop-up books seems almost radical in their laborious method of production and the way they force the reader to slow down and explore with hand and eye something which is physically present. Megabeasts feels like a luxury item in the sense that it is clearly the work of a master craftsman but also in the way that it takes time to appreciate. This is not a book that you read between the Tweenies and Fimbles or in five minutes before bedtime. It deserves and demands to be savoured.

Sabuda and Reinhart's next project is a series called Encyclopedia Mythologica dealingwithdragons, fairies, gods and heroes. That sounds about right - these two men perform a kind of wizardry.