Gigantoraptor
No direct evidence of feathers was preserved with the skeleton. It might have been "naked" because it is three hundred times more massive than the smaller feathered species. Very large animals rely more on mass for temperature regulation, losing the insulating coverings found on their smaller relatives. Arm feathers were probably still present on Gigantoraptor, since their main functions, such as display and covering the eggs while brooding, are not related to the regulation of body heat.