The long and the short of tails

Amniote tails display a wide variety of features for adaptation to diverse environments. Each feature originates from its own distinct developmental processes, and these processes in turn attest to an organism's evolutionary history. In this perspective, we discuss the ontogeny of tails from embryonic to adult stages, amniote tail regeneration, the mechanisms underlying tail length and neural systems, and the benefits of studying tails across vertebrates, in mammals, birds, and non-avian reptiles.