MIMETIC MUSCULATURE. “Non-mammalian vertebrates use these muscles in breathing and feeding functions but in mammals they also take on new roles assisting with gathering sensory information, making facial displays or expressions during social interactions, moving the external ears, and changing the size of the openings for the external nose, eyes, and mouth.”
http://onlinelibrary.wiley.com/doi/10.1111/joa.12440/full