What is the significance of the Fuxi Nuwa Diagram?

The two cornerstones in the north corner of Tomb 4 of the Five Helmets Tomb are depicted as Fuxi and Nuwa, both of which depict the upper body of a man and the lower body of a dragon. On the right side of the picture, Fuxi is a man, with his hands holding up a disk painted with a three-legged crow, symbolizing the sun. In China's ancient legends, Fuxi was the emperor of the east and the son of Hua Qing who was born after stepping on the footprints of the god of thunder in the Lei Ze. On the left side of the picture, Nuwa is a woman figure with a fair face and long hair draped over her shoulders. In her hand, she holds a disk painted with a toad, symbolizing the moon. Nuwa is the goddess of creation, who created mankind from yellow clay. It is said that Fuxi and Nuwa became the "Ancestor Master" and "Ancestor Nurse" respectively after they were married. Therefore, it is believed that this picture of Fuxi and Nüwa symbolizes the birth of mankind.