Nanuqsaurus is one of the closest cousins of T.rex, but would have looked very different. It was still a fierce, toothy predator that walked on two legs, but it was a dwarf: it was less than half the size of its famous cousin.
Nanuqsaurus lived on a floodplain on the edge of an inland sea in North America, in an area that was also home to Troodon.
Nanuqsaurus, like Allosaurus, would have been able to hear low-frequency sounds.
Nanuqsaurus' teeth were banana shaped but serrated like a carving knife – perfect for sawing into flesh.
A keen sense of smell was important in tyrannosaurids. Their olfactory bulbs are large. Nanuqsaurus would have been excellent at locating food over large territories.
Nanuqsaurus is one of the newest dinosaurs to science. It was described as a new species in March 2014 by American palaeontologists, Tony Fiorillo and Ron Tykoski. Fiorillo has been leading dinosaur-hunting expeditions to the cold, frozen mountains of northern Alaska for over a decade. Some of his field sites are within the Arctic Circle.
Vision: Like all tyrannosaurids, Nanuqsaurus would have had excellent binocular vision for depth perception and a heightened ability to detect movement while hunting for prey.
Skin: Nanuqsaurus probably had scales covering much of its body. Based on other tyrannosaur discoveries, we can say it might also have had some feathers.
Brain: All theropod dinosaurs, like Nanuqsaurus, were relatively intelligent with large brains and excellent senses. They were much more intelligent than other groups of dinosaur like the sauropods or ceratopsians.
Prey: Some scientists believe that Nanuqsaurus would have hunted in packs, based on the discovery of an aggregation of fossilised Albertosaurus individuals, Nanuqsaurus' closest relatives. However, this behaviour is highly debated.
Bite: Tyrannosaurids like Nanuqsaurus are experts in delivering crushing bites to their prey. They would have generated the strongest bite forces known.
Nest: From studying Nanuqsaurus' closest relatives, palaeontologists believe its eggs would have measured between 10-15cm (4-6in) long, had a shell a couple of millimetres (0.07in) thick and looked bird-like in shape.
Nanuqsaurus is part of the theropod and tyrannosaurid dinosaur clans. These include some of the large, bipedal, carnivorous dinosaurs, including Tyrannosaurus rex.
Nanuqsaurus may have guarded their eggs and watched over their offspring. They were certainly too big to sit on their nests, so they may have used rotting plants to incubate their brood, much like modern alligators do today.
Nanuqsaurus could grow a massive 50kg (110lb) each year before it reached sexual maturity. That's almost the weight of a person each year.
Dinosaurs could grow brain tumours. One tyrannosaur fossil has been uncovered with a spongy mass in its skull cavity. This would have made the individual a bit wobbly and accident prone in life.
Nanuqsaurus would have been the apex predator on its patch, feeding on smaller herbivorous dinosaurs, including ceratopsids and hadrosaurs.