At 10 meters in length, the woolly therizinosaur (Arctonyx americensis) is the largest of the herbivores of the North American tundra. This species eats grass and small plants, which it crops from the ground with a flattish-tiped beak.  Its snout is elongated, and its eyes are set far up to give the best vision while grazing.  In the winter, these dinosaurs grow shaggy coats of plumage, and the enlarged neural spines over their shoulders support fat stores for times of famine.

    Unlike the seculasaurids, which migrated to North America during the Miocene, the woolly therizinosaur is a ceronychid, closely related to the moora and panha that live just across the Bering Sea. 

(Text by Daniel Bensen)