Today, Siberia has relatively low biodiversity, but that wasn't always the case. During the last Ice Age, the region was covered with a biome known as the "mammoth steppe," a grassy landscape densely populated by ?" as the name suggests ?" woolly mammoths, as well as species of bison, horse, reindeer, and musk ox. These creatures lived in symbiosis with the fast-growing grasses, and the ecosystem was so successful that it managed to spread over much of Europe, Russia, northern Asia and Canada.