“Dinosaur” is still sometimes used as a pejorative. The image of a lumbering swamp monster doomed to extinction has proved too appealing an insult for some to abandon. They should beware, though. Nothing is more out-of-date and stuck-in-the-mud than to imagine that dinosaurs were anything other than astonishingly successful. Over the past half century, a palaeontological revolution has transformed our understanding of them. Recently, it has been picking up ever more dramatic speed. “One by one,” Michael Benton writes, “the speculations about evolution, locomotion, feeding, growth, reproduction, physiology, and, finally, colour have fallen to the drive of transformation.” Dinosaurs these days are the cutting edge.

Benton’s new book explains why. No one with even the faintest interest in the subject will want to miss it. He is one of the world’s most eminent palaeontologists, and throughout his distinguished career has been at the heart of the step change in dinosaur palaeobiology. He is also, though, a natural communicator. As a child, he had yearned to become a palaeontologist so that he could be paid for doing what he loved: “collecting fossils, drawing ancient creatures, and reading about dinosaurs endlessly”. As a professor, he has made sure to pay back his debt to the amateur enthusiast he once was. He served as a consultant on the BBC’s Walking With Dinosaurs; he founded an education programme to take palaeontology into schools. Now, with The Dinosaurs Rediscovered, he has written a book for the general reader that explains not just what specialists know about them, but how they have come to that point. It is an account, as Benton puts it, of “the transformation of palaeontology into science”.

I defy anyone who is, like me, a non-scientist to read it and not feel a sense of wonder at what palaeontologists now understand. So much that even 20 years ago was supposition has hardened into fact. Benton opens his book on 27 November 2008: the day his team became “the first ever – or at least the first on record – to have seen evidence of melanosomes in dinosaurs”. These hollows inside the feathers of a bird-like dinosaur from China, Sinosauropteryx, had once contained pigment. Because the melanosomes were ball-shaped, Benton was able to identify what colour the feathers had been. Sinosauropteryx had been ginger. Benton’s excitement at this discovery is engagingly articulated. “Our first desire was to rush out and tell the world – to call the press and shout from the rooftops! On the other hand, as scientists, we are trained to be careful, and we wouldn’t want to look foolish by making such a wild claim if the evidence wasn’t there.” But the evidence was there; and Benton is at pains to explain just how he and his colleagues, banishing the 125 million years that separated them from the lifetime of the dinosaur they were studying, could be certain that their claim was justified.

When they write about their profession, most palaeontologists choose to emphasise expeditions into the wilds. Benton, a veteran of many field trips to North America and China, prefers to dwell on what can be learned back in the office. It is not only fossil microscopy that has delivered the astonishing advances in our understanding of dinosaurs over the past couple of decades. So, too, have advances in engineering models and computational methods. “Although they may seem less exciting because they do not involve Land Rovers, sweat and exotic desert locations, they can be crucial in resolving questions.” Benton demonstrates just how momentously dinosaurs have been brought back to life inside computers. Though he dismisses any prospect of obtaining dinosaur DNA, his achievement is to make those in his book appear far more real as living organisms than anything that might be achieved by CGI.

“Until recently,” he writes, “the way we viewed dinosaurs – whether as lumbering, slow reptiles, or active, fast movers – depended on the prejudices of the moment … Now we know for sure how dinosaurs stood and walked, their speeds, and whether they could fly and swim.” The trend has been repeated in the field of dinosaur behaviour. Scientists can now be confident how fast a T rex could move – in a way that would have been impossible in 1993, when Jurassic Park was released. And they have come to an increasingly sophisticated understanding of how dinosaurs fed. Engineering methods reveal that the maximum bite force of an Allosaurus was 1,000 times that needed to crack a boiled egg. A tyrannosaur would puncture its victim with its front teeth, then tear off the flesh by pulling back its head. Entire food webs, deriving from new approaches in ecology, are being sketched out. “But,” Benton adds, “there is so much to do.”

Nothing better illustrates the change in our understanding of dinosaurs than the discovery of why they went extinct. Forty years ago, no one knew that an asteroid had smashed into what is now the Yucatán peninsula, ending the Mesozoic era. Similarly, 20 years ago, it was very much a minority position that birds should be classified as dinosaurs, and that dinosaurs had thus not been entirely wiped out. Benton is excellent on both these recent developments, but he is most interesting of all on an unsolved puzzle. We know where the dinosaurs went, but how and when did they originate? As one of the world’s leading authorities on the mass extinction that marked the start of the Mesozoic – an event even more devastating than the one that ended it – Benton provides the reader with an outline, but can do little more than that. The ancestral dinosaurs remain undiscovered. “This is a chapter,” he writes, “that will definitely need rewriting in ten years’ time.”

• The Dinosaurs Rediscovered: How a Scientific Revolution is Rewriting History is published by Thames & Hudson (£24.95). To order a copy go to guardianbookshop.com or call 0330 333 6846. Free UK p&p over £15, online orders only. Phone orders min p&p of £1.99.