These two books about dinosaurs are mirror images of each other. Lukas Rieppel's is an account of the discovery, financing, reconstruction and display of the fossils recovered in the second ‘dinosaur rush’ to the American West around 1900, with a concluding chapter on the latest modern studies. Michael Benton's is an introduction to all the modern revelations, with appeals to historical examples to illustrate how perceptions of this much-publicized group of extinct animals have changed since their remains were first discovered.

Rieppel's book is obviously the more relevant for historians and is a major addition to the literature that is expanding our understanding of the complex factors that govern how palaeontology has come to operate in the modern world. It goes behind the scenes to reveal what actually happened in both the discovery of these spectacular fossils and their display in the great natural-history museums founded in the United States in the late nineteenth century and early twentieth. The palaeontologists are there, of course, active in exploration, excavation and description, always likely to fall out with one another over technicalities. But Rieppel is also interested in the capitalists who financed the expeditions and the museums, tycoons like Andrew Carnegie and J.P. Morgan, who saw that spectacular displays could be presented to the public as evidence of their generosity and the success of the economic system they represented. The museums they endowed brought in not just anatomists to reconstruct the skeletons but also specialists in display who drew on the techniques of P.T. Barnum to create lifelike poses and backgrounds. They made sure the results were splashed across the headlines of the popular press and later exploited the new medium of the motion picture. Conan Doyle's endorsement of the movie based on his novel The Lost World created a debate by implying that its scenes represented real life (a confusion that suggests a level of ignorance about geological time among the audiences).

When it comes to the messages being conveyed by the displays, the situation becomes more complex. Henry Fairfield Osborn at the American Museum of Natural History was the leading exponent of orthogenesis, often used to imply that the dinosaurs were a group doomed to extinction by inbuilt trends leading to gigantism and overelaborate ornamentation. This fitted in with the popular view that the herbivores, at least, were sluggish, stupid beasts incapable of any serious response to challenges from carnivores or the environment. On the other hand, the realistic paintings by Charles Knight depicted conflicts between carnivores and herbivores, conveying a more active image. Rieppel notes that another painting of woolly mammoths seems intended to contrast the individual ferocity of the reptilian conflicts with the more intelligent and cooperative behaviour of the mammals, prefiguring the eventual emergence of complex modern societies. He argues that this progressionist image is at variance with the general assumption that the period was the heyday of social Darwinism, whether based on individual or group competition. On this interpretation, Carnegie and his fellow capitalists were trying to counter the more negative image of their activities by displaying evolution as the emergence of coordinated social action.

I have to say I was left wondering whether the audiences actually grasped the messages supposed to be implicit in these displays. I am impressed by the transformation in the understanding of dinosaurs that took place in the late nineteenth century, which was boosted by the discoveries of the first and the second American dinosaur rushes (the first being the scene of the rivalry between O.C. Marsh and E.D. Cope). They had at first been seen as gigantic lizards or crocodiles – think of the reconstructions at Crystal Palace – and could be passed off as variants on a stage in the ascent of the chain of being towards humankind. In the 1860s it was recognized that some were bipedal, and over the following decades new fossils revealed a fantastic array of bizarre forms quite unlike anything alive today. The displays that Rieppel describes presented the scientists and the public with a flourishing branch of the tree of life that had to be lopped off to make room for the rise of the mammals. Whatever the intentions of those who financed the displays, their efforts actually promoted a world view in which even the most successful groups can be swept aside by extraneous factors, to be replaced by formerly obscure types that turned out to have more potential.

Benton's book has less to offer historians since it is intended to provide an up-to-date account of the latest fossil discoveries and the increasingly sophisticated techniques by which they are interpreted and displayed. It does, however, use historical examples, including the first Lost World movie, to illustrate how ideas have changed through time. It will be of interest to those who want to understand how scientists actually work in this area, Benton himself being one of the most active and authoritative experts in the field. Linking with the theme of Rieppel's book, it also gives us an insider's view of how the results are presented to the public. Benton was a consultant for the BBC's Walking with Dinosaurs television series in 1996 and understands how movies such as Jurassic Park were made. He certainly appreciates how efforts are made to bring the creatures to life and to tell us something about the past history of life on Earth – but with less emphasis on whatever ideological messages those who commission the displays might have in mind.