Rediscovered in 1938, they were thought to be extinct. Lampreys ... and they are currently not at risk of extinction. Musk oxen, native to the upper regions of North America, have been around ...

About 3 thousand years ago, apparently due to climate change, musk oxen in Eurasia became completely extinct. They remained only in hard-to-reach places in North America and Greenland. To return ...

Related: Muskox Calf's First Venture Into a Leaf Pile Is Full of Joy and Wonder But never fear, head butting is a natural part of musk ox behavior ... Their prehistoric range is far more ...