What does Xuanwu look like in ancient mythology? .....

Xuanwu is a spiritual thing composed of turtles and snakes. Xuanwu originally meant Xuanming, and the ancient sounds of Wu and Ming are interlinked. Xuan means black; Ghost means yin. At first, Xuan Ming described the tortoise's divination as follows: the tortoise's back is black, and the tortoise's divination is to invite the tortoise to the underworld to ask questions, bring back the answers and show them to the world in the form of divination. Therefore, the earliest Xuanwu is the tortoise. The historical book "Selected Works" volume 15, Zhang Heng's "Four Fu Xuan" said:' Xuanwu leaves a shell, and the snake bends and corrects itself.' Shan Li notes the cloud:' When a turtle meets a snake, it is called Xuanwu.' Wang Liangchuan in the History of the Later Han Dynasty: "Hong Fu Nv" says: "Wang Liang is the Lord of Xuanwu." Li Xian pointed out: "Xuanwu, the God of the North, is a combination of tortoise and snake." Xuanwu is the god of water and the god of the north. Wang Liangchuan in the later Han Dynasty: "Xuanwu is the name of the water god." "Rebuilding the Integration of Weft Books" Volume 6 "The Emperor of the River Map":' Born in Xuanwu, North China, ... The town is in the north, mainly due to wind and rain. Edit this paragraph of the Northern Emperor, but Xuanwu was upgraded to the Northern Emperor "Zhenwu Emperor" by later Taoist priests. Different from the other three spirits. Other green dragons and white tigers only worked as gatekeepers of mountain temples, and Zhu Bird worked as Xuan Nv for nine days. In ancient times, people imagined some stars in the north as turtles and snakes, and called them divine kings. In folk beliefs, the divine monarch has the following sacred characteristics: (1) the god of the north.