Prehistoric lungfish

Ceratodontidae is an extinct family of lungfish with fossils known worldwide from the earliest Triassic to the Eocene.

Youngolepis is a genus of prehistoric lungfish which lived during the Early Devonian period (Lochkovian to Pragian stages, about 407-416 million years ago). Fossils of Y. praecursor have been found in the Xitun Formation of China & the Bac Bun Formation of Trang Xa, Vietnam. Some additional fossil specimens from the Xishancun Formation of China have been referred to Youngolepis sp. & represent the oldest known occurrence of the genus. In addition, Y. praecursor is also found in the Xujiachong formation

Dipteridae is an extinct family of prehistoric lungfishes which lived in the Devonian period.