Giant predator lizards can't evolve in the presence of big mammal predators. So the lesson is that mammals suppress much of the evolutionary potentia… - Robert T. Bakker

One might expect that mammals would have taken over the land verte­brate communities immediately, but they did not. From their appearance in the Triassic until the end of the Creta­ceous, a span of 140 million years, mam­mals remained smal and inconspicuous while all the ecological roles of large ter­restrial herbivores and carnivores were monopolized by dinosaurs; mammals did not begin to radiate and produce large species until after the dinosaurs had al­ready become extinct at the end of the Cretaceous. One is forced to conclude that dinosaurs were competitively su­perior to mammals as large land vertebrates. And that would be baffling if dinosaurs were "cold-blooded." Perhaps they were not.

Both birds and crocs have the identical plan to their specialized gizzard apparatus, and this type of internal food processor is absent in the other "reptiles" - lizards, snakes, and turtles.

The sum of evolutionary evidence is thoroughly damning. In nearly every modification of the evolutionary process made in the duckbills as they developed from their dryosaur ancestors, the duckbills suffered a diminution of their swimming potential. Their fore- and hind paws became shorter and more compact, not longer and more widely spread. Their tails got weaker and stiffer. Far from being the best, the duckbills must have been the clumsiest and slowest swimmers in all the Dinosauria. If pressed, they probably could paddle slowly from one riverbanck to another. The central theme of their bodily evolution was indeed specialized - orthodox theory was right on that point - but the direction of specialization was landward. These dinosaurs were specialized for a totally terrestrial existence.