Dale Russell from the Canadian National Museum was the first to notice a curious twist in the evidence for my case. Dinosaurs did indeed have a much lower ratio to their prey than did finback reptiles or spiders. But their ratios were still higher than those obtaining today in the Serengeti, in Indian game parks, or in most ecosystems today where large mammals are the top predators.(Dinosaur Costume) Predatory dinosaurs average about 3.5 percent of their prey. In the best-studied modern game park, the Serengeti, the predators average only one tenth of 1 percent or less—in other words, their prey is nearly a thousand times greater in number than the predators. The average ratio to prey of all modern predatory mammals is 1 percent or less—three or four times less than the ratio of the predatory dinosaurs.
If dinosaurs had been as warm-blooded as modern lions, why were their predator-to-prey ratios so much higher? That was a question requiring an answer. Dale Russell concluded that the dinosaurs’ metabolic rates must have been three or four times lower than the mammals’. But I believe his conclusion was incorrect. The predator-to-prey ratios for fossil mammals average about 3 or 4 percent, much higher than those calculated for today’s mammals, and identical to those of the dinosaurs. (dinosaur equipment)Do these averages imply that the extinct mammals were cold-blooded? That is hardly likely. (dinosaur supplier)The extinct predators that established the percentages were perfectly normal mammals—saber-toothed cats, hyenalike carnivores, giant wolflike bears. Nothing in their anatomy has ever suggested they were cold-blooded. Paleontologists who had studied them have universally assumed—correctly, I think—that they were as warm-blooded as any modern mammals.