During the Ice Age, giant mammals such as mammoths, sabre-toothed cats and woolly rhinoceroses once roamed Northern Europe and America. The cold oceans of the northern hemisphere were also home to giants like Steller’s sea cow, which grew up to eight metres long and weighed up to ten tonnes, and has been extinct for around 250 years. Now an international research team has succeeded in deciphering the genome of this ice-age species from fossil bones. They also found an answer to the question of what the genome of this extinct species of sea cow reveals about present-day skin diseases.