One type of early Australian Art is called “xray art.” The form is drawn as though the viewer can see through to the skeletal structure of the animal and its entrails. p 220 "Spirit and Art: Pictures of the Transformation of Consciousness," by Van James 2002 Steiner Books
Xray painting is not only widely known of Aboriginal Australian art but it is also common to other tribal cultures.
The images are more spiritual than simply being useful pictures created by hunters. Although the nomads would certainly have opportunity to become familiar with the inside of animals that they regularly carved, the art is thought to be more "essentially spiritual" than this. Van James indicates that early tribal cultures could see phenomenon much more deeply than contemporary people who merely relate to the outer exterior of objects.
The stories of aboriginal people, like the one related on page 201, talk about the dreamtime and the creation of the world. It is thought that xray, line art drawings were a way of recording creation stories.
The drawings may be of even greater spiritual significance. Tradition would have them "produced only in part by the living," as the spirit of the deceased and the dreamtime gods were said to assist in the creation of the artwork. In this way messages of spirits from the dead were channelled through the living.
To show an example of what is meant by this van James shows older, simpler spirit drawings called "MIMI." The spirit are said to have left their images on the rocks as they "melted into them." fig 263 page 202 Google Books
Explore further examples of xray, line art on page 201 (figures 262 and 263) of the same text and then try this class exercise from Enchanted Learning