Two Phases in the Evolution of the Body Size of Dinosaurs

During the Late Triassic – Jurassic phase of the evolution of dinosaurs, their mean and maximum body size increased concurrently with increasing species diversity. On the contrary, in the Cretaceous, although the number of dinosaur species increased, the body size ultimately decreased. This might have been connected with the increase of the number of land masses and the decrease of their areas in the Late Cretaceous caused by global tectonics.