Shape of Mesozoic dinosaur richness

The richness of Mesozoic Dimosauria is examined through the use of a new global database. Mesozoic dinosaurs show a steadily increasing rate of diversification, in part attributable to the development of new innovations driving an increasing variety of behavioral strategies. The data do not suggest that dinosaurs were decreasing in richness leading to extinction during the last similar to 10 m.y. of the Cretaceous. Refinement of the dating of dinosaur fossils, rather than the collection of more dinosaurs, is the best way to resolve globally the rate of the Cretaceous-Tertiary dinosaur extinction.