Jiutian Xuanniao and Xuanniao are both ancient China Shenniao. Nine-day Xuanniao is classified as Phoenix, which is the mount of Shao Hao, the eldest son of Xuanyuan Huangdi. According to the Book of Songs, the dark bird is a black swallow, which belongs to the category of swallows, so the difference between the nine-day dark bird and the dark bird lies in the different categories.
In The Classic of Mountains and Seas, the image of the nine-day bird is actually a swallow. However, with the development of the tribe, the later images evolved into cockscomb and peacock-tailed phoenix.