The animal had a covering of simple feathers or protofeathers. The feathers were seen in fossilized skin impressions from near the jaw and tail. They are not identical to modern bird feathers: they lack a central shaft. Their likely function was to retain body warmth. They could not have been used for flight. Adult tyrannosaurs found in Alberta and Mongolia have skin impressions which appear to show the pebbly scales typical of other dinosaurs. 