The epicranial aponeurosis (aponeurosis epicranialis, galea aponeurotica) is an aponeurosis (a tough layer of dense fibrous tissue) which covers the upper part of the cranium in humans and various other animals. In humans, it is attached, in the interval between its union with the occipitofrontalis muscle, to the external occipital protuberance and highest nuchal lines of the occipital bone; in front, it forms a short and narrow prolongation between its union with the frontalis muscle or frontal part of the occipitofrontalis muscle.