First record of Araucaria with leafy shoots and reproductive organs from the Lower Cretaceous of NW China and its historical biogeography

The modern Gondwanan genus, Araucaria , exhibited a worldwide distribution during its early evolution in the late Mesozoic. However, the scarcity of fossil records restricted exploring its early radiation and evolution. A new species, Araucaria gansuensis sp. nov. was described based on well-preserved leafy shoots associated with female cones, deciduous pollen cones and bract-scale complexes from the Lower Cretaceous of Northwest China. Maximum parsimony analysis revealed that the phylogenetic position of A. gansuensis is within the basal clade of Sect. Eutacta . Moreover, palaeobiogeographic analysis suggested that Araucaria possibly originated in the low latitudes of the Pangea and formed differentiation centers in Laurasia (East Asia) and Gondwana (South America) in the Middle Jurassic. Furthermore, with the breakup of Pangea, Araucaria rapidly radiated globally, and exhibited a more extensive distribution in the Northern Hemisphere during the Cretaceous. The discovery of A. gansuensis as a significant representative has unveiled a pathway for the dispersion of Araucaria in East Asia and Europe. Subsequently, Araucaria , which had a more primitive lineage, started declining and facing extinction in the Northern Hemisphere in the Early Paleocene due to factors such as geographic isolation, climatic variations, and expansion and dominance of angiosperms. • A new species, Araucaria gansuensis sp. nov. was reported from the Lower Cretaceous of NW China • Fossils Araucaria , which were distributed in East Asia during the Mesozoic, are the common ancestor of modern Araucariaceae and have primitive features. • The existence of the Pangaea facilitates the spread of Araucaria , and its breakup is a driver of divergence of Araucaria.