Carnivorous pokemon were slow to develop near the poles, and the large, peaceful, and extremely expressive Amaura were a testament to the directions in which evolution can go without them. From the moment they hatched out of their enormous eggs, Amaura were already too large for any of their small, poorly attested contemporaries to have any hope of devouring. With no threats to their continued survival, Amaura became noted for their extremely long lifespans. But with no foes to defeat in battle the process of evolution was equally slowed, and for developing a remarkably honest means to communicate with other pokemon. Unlike the facial expressions nearly exclusively used to expression emotions today, an Amaura's colored sail could be seen from a vast distance and was incapable of deception, which has become a danger to wild pokemon in a world where predators can smell fear.
It is unknown to science if climate change or predation ultimately did the Amaura in, but the popular imagination has overwhelmingly preferred the latter explanation. The idea of an idyllic polar world full of shy, innocent Amaura being torn upside-down by a horde of cold-resistant Tyrantrum, or Lapras, or the distant ancestors of Beartic, is far more fascinating than the idea of these pokemon being destroyed by nothing more than another of many shifts of this planet's temperature over the course of geologic time.
Modern Amaura trainers can find support for both narratives; Amaura seem friendly, open, and innocent by the standards of pokemon today, but they can be taught to battle. They come equipped with tough stone bodies which are difficult to devour and claimed by some to be an artifact of defossilization, and many argue that a purely ice-type Amaura, while edible, would have lacked body structure and could not support its own weight.