Osborn named "Tyrannosaurus rex" and "Velociraptor", and many other dinosaurs. His biographer Ronald Rainger said he was "a first-rate science administrator and a third-rate scientist". Under his leadership, staff of the American Museum of Natural History worked on displays. The museum became one of the top exhibitions in the early twentieth century. As a result, the murals, habitat dioramas, and dinosaur mounts attracted millions of visitors, and inspired other museums to imitate. His decision to invest heavily in exhibitions angered curators, who hoped to spend more time on their own research. 