Take the case of the tail presented here. Paleontology presents anumber of ancestral milestones in the development of the axialskeleton and gives a glimpse into the morphology that existedunder the ecological conditions relevant to the time of these earlyorganisms. To understand the selective pressures that would haveaffected the fitness of an extinct organism, we need to know moreabout performance advantages inherent to their morphology. Wecan turn to similar morphologies of extant organisms, or use toolslike bioinspired robotics and computational models if a good livinganalog does not exist.