English: Nanuqsaurus is a tyrannosaurid theropod from Alaska. 70 million years ago, Alaska experienced cold weather and extreme changes in daylight during the year. Prey availability likely would have increased during the summer, then declined in the dark winter, leaving predators with little to eat. In its initial description, Nanuqsaurus was estimated to have been 5–6 m long and 500–900 kg in weight. This diminutive size was postulated as being an adaptation to its high-latitude habitat. However, later studies suggested that its supposed small size was unfounded, and that it was likely similar in size to other North American tyrannosaurids - as much as 9 m in length.