In particular, dinosaurs did not participate in the Cretaceous Terrestrial Revolution, some 130 to 100 Ma, when flowering plants, leaf-eating insects, social insects, squamates, and many other modern groups radiated substantially.
2009 February 6, Michael J. Benton, “The Red Queen and the Court Jester: Species Diversity and the Role of Biotic and Abiotic Factors Through Time”, in Science, volume 323, number 5915, pages 728–732