The discovery of a large ceratodontiform lungfish from the Middle Triassic (Anisian) of Shanxi, China

Ceratodontiformes is the only extant order of Dipnoi (lungfishes). Fossil remains of this group are rare in Triassic deposits in China. Here, we report the recent discovery of a large ceratodontiform lungfish from the Anisian (Middle Triassic) Sinokannemeyeria Fauna in the Taigu District of Jinzhong City, Shanxi Province, China. The specimen was preserved in the argillaceous siltstones from the Third (uppermost) Member of the Ermaying Formation, including remains of 20 caudal vertebrae and associated elements (‘supraneurals’, interhaemals and dorsal and ventral radials) as well as a series of dorsal fin rays. The discovery documents the oldest articulated ceratodontiform in East Asia, predating the previously known articulated ceratodontiform from the Early Jurassic Yuzhou Biota by at least 43 Ma. With an estimated length of ~162 cm, it represents the largest articulated ceratodontiform known so far in the Triassic. The new finding adds to our knowledge regarding body size, morphological diversity, and the paleogeographic distribution of early ceratodontiforms.