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

When the dinosaurs fell at the end of the Cretaceous, they were not a senile, moribund group that had played out its evolutionary options. Rather they were vigorous, still diversifying into new or­ders and producing a variety of big­brained carnivores with the highest grade of intelligence yet present on land.

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.

I do not be­lieve birds deserve to be put in a taxo­nomic class separate from dinosaurs.