Dinosaur reconstructions have been exhibited in public for over a hundred years. During that time, scientific and public understanding of these extinct animals has changed considerably. Changes in perception have influenced and been influenced by the three-dimensional reconstructions mounted in museums and galleries, and these in turn have been influenced by the availability and use of mounting materials and techniques. The dinosaur exhibition in The Natural History Museum (NHM) in London contains examples of original, altered, and new dinosaur reconstructions that are described here—two, Gallimimus and Massospondylus, in detail. The final form of any reconstructed dinosaur is often influenced by factors beyond the control of the conservation, preparation, and mounting workers involved.