First record of Cladophlebis beijingensis from the Middle Jurassic Yaojie Formation, Baojishan Basin, Gansu, China, and its palaeobotanical implications

Ferns were diverse in the Middle Jurassic floras of Gansu, northwestern China. Newly discovered, well-preserved fern fronds from the coal-bearing shale member (J2y2) of the Yaojie Formation in the Baojishan Basin are identified as Cladophlebis beijingensis Chen et Dou, representing the first record of this species from the basin. This material extends the known fossil record of C. beijingensis and provides the first detailed cuticular data for the species, offering microstructural criteria that strengthen species-level identification within the morphogenus Cladophlebis. To place the Baojishan occurrence in context, we also synthesise published Cladophlebis occurrence records from the Mesozoic of China and summarise broad spatiotemporal patterns in reported localities and mapped extent, recognising that compilation-based taxonomic and sampling biases limit definitive interpretations. Independent regional evidence (palaeoclimatic zonation, associated floras, and spore – pollen assemblages) is consistent with generally warm and humid conditions in the Baojishan Basin during the early to middle Middle Jurassic, with a tendency towards relatively drier, sub-humid conditions later in the Middle Jurassic.