What adaptations of the wild yak enable it to survive in the alpine biome?

The alpine biome is one of the coldest biomes on the planet, it is generally because of the high altitudes. The summer temperature varies in between -12 to 10 degree Celsius, and the average precipitation in the biome is about 30 cm in a year.  

The animals living in the region, adapt to the cold by migrating to warmer regions, hibernating, or insulating their bodies with the help of fat and fur layers. Their bodies seem to possess shorter tails, legs, and ears, in order to minimize the loss of heat.  

One of the animals living in the alpine biome is the wild yak, the animal has adapted to the biome with the help of dense and wooly coats, specially amended feet, horns to dig for food, and if necessary does the migration in winter times to the warmer regions.  

is called echinoderms