New fossil materials of hybodus (Chondrichthyes) in the Middle Jurassic found in Chuanjie Basin of central Yunnan Province

Chuanjie basin in Lufeng County of Yunnan Province produced hybodontoidea's fossils in Middle Jurassic strata, which include Hybodus houtienensis, Hybodus xinzhuangensis (New species), and Hybodus chuanjieensis (New species). Hybodus houtienensis is one of the earliest hybodontoidea found in China, the holotype consists of broken spines, and subtype specimen is a tooth crown. On the basis of the new fossil material found in the same strata of Chuanjie Basin, we have added Subtype specimens of the Hybodus houtienensis, also added the description about it; the authors set up two new hybodus species:Hybodus xinzhuangensis and Hybodus chuanjieensis, thus enriching the group of "houtienensis hybodus belt". The biostratigraphy of Hybodont, ancient environment of biostratigraphy and geographical distribution were also discussed.