From “The hare and the tortoise: Or, rather, the dinosaur and the crocodile” (The economist, Dec 3rd 2011), we learn:
Fashion affects all human activities, and science is not exempt. In the field of palaeontology, for example, the stock of crocodiles is rising. Their role in Mesozoic ecosystems, including as predators of dinosaurs, has been reassessed over the past few years—and their diversity of forms (even including herbivorous species) is becoming increasingly apparent. This shift of perception is causing fossil hunters to take a renewed look at crocodiles, dinosaurs and the similarities and differences between them.
The researchers report that dinosaurs grew more quickly than crocs.
… the features indicating rapid growth were added one by one during the Triassic (the period immediately before the Jurassic). That is not terribly surprising. What is surprising is that all of these features were present in the last common ancestor of dinosaurs and crocodiles. The former, in other words, perfected rapid growth and went on to dominate the Mesozoic, while the latter gave it up.
Crocodiles had the last laugh, though. Fast-living dinosaurs were unable to survive the crisis at the end of the Cretaceous, when an asteroid hit Earth and brought photosynthesis to a halt. Slow-living crocs, by contrast, were able to cling on until conditions improved, and are now found throughout the tropics and subtropics. Thus, 65m years ago, were the fates of two groups of animals decided by evolutionary differences inculcated 220m years ago.
The money shot would be to know how that happened