In the United States wealthy tycoons funded fossil-hunting expeditions and new natural history museums to display their discoveries. Dinosaurs from the Western states dramatically transformed the way the ascent of life could be represented because they were quite unlike any living reptiles and confirmed that the ‘tree of life’ had many more branches, some of which had disappeared completely. There was increasing evidence of relatively abrupt transitions in the earth’s history, forcing geologists and evolutionists to reconsider their impression that change had been more or less continuous. As the tree of life became more complex, the assumption that the human species was the inevitable outcome of progressive evolution became less plausible. Although non-Darwinian theories were retained by some authorities, the new vision of evolution came to seem more compatible with Darwin’s vision of an open-ended and less predictable process.