This blog is devoted to paleontology, but it is also motivated by my love of gaming. Fantasy creatures are vivid, in part, because they are realistic enough to imagine. Dragons and wyverns, in particular, are strange to imagine because no living creatures resemble them. It is reasonable to infer that in the past, peoples of many cultures found fossils of dinosaurs, and mythical dragons are a pretty good reconstruction if you find incomplete skeletons.
But vertebrates as a whole are more remarkable than dragons. Deriving from the same kit of parts–skull, spine, ribs, and four limbs–vertebrates have evolved in amazing variety over the past 500 million years. Dinosaurs might have been even better evolved than modern mammals because of the efficiency of the biped, hybrid, and quadruped variants counterbalanced by substantial tails. If in fact they had the same high-efficiency respiration system we see in modern birds, that might explain the massive size of dinosaurs without the need for a higher percentage of oxygen in the atmosphere. Mammals may have efficient endothermic metabolisms, but it is entirely possible that the most effective vertebrate body plans were wiped out with the K-T extinction. Since evolution works by random mutation, there is no reason to assume that the mammals that survived the K-T extinction would be ‘better’ than the vertebrates that got wiped out.
Tail-less bipedalism is a good example of a loss of more efficient variations. Birds lack substantial tails, limiting how well they can run. Humans may be the weirdest of all, using large arms to counterbalance because of a complete lack of tails, and plantigrade feet for basic stability. Frequent back and knee problems among humans suggests that our body-plan was ‘good enough’ for adaptive success, but not at all optimal. Getting a sense of the many vertebrate possibilities from Permian tetrapods to Cenozoic bats and primates can give us a more balanced, skeptical perspective about the human condition in relation to our world. I find this study endlessly entertaining and amazing.