It is hard to domesticate an emu, and no-one ever rode a kangaroo into battle

The zoological lottery that Jared Diamond describes - the pure chance of whether your local animals can be domesticated - enormously favoured Europe and Asia. Australia, by contrast drew a very short straw. It is hard to domesticate an emu, and no-one ever rode a kangaroo into battle. The Americas were almost as badly off, but they did have the llama. Llamas cannot compete with horses for speed, or donkeys for pack power; they also have an infuriating habit, when tired, of just stopping and refusing to move. But they are extraordinarily well adapted to high altitude; they cope well with the cold and can forage for their own food; they cab provide wool, meat and manure; and, although they cannot carry people, a healthy llama can comfortably transport about 30 kilograms of goods.

N. MacGregor, A history of the world in 100 objects (2010), 403
[73: Inca gold llama]