A fossil fruit wing of Dipterocarpus from the middle Miocene of Fujian, China and its palaeoclimatic significance

Dipterocarpus zhengae sp. nov. is described from the middle Miocene Fotan Group of Zhangpu county, Fujian Province, Southeast China on the basis of a fruit wing. Three kinds of venation of the calyx longer lobes (enlarged sepals) occur in the winged fruits of extant Dipterocarpus. The fossil species is referred to the kind having three primary veins and within that category is most similar to extant Dipterocarpus gracilis Blume in the size of the longer lobe as well as its venation. The occurrence of the fruit wing of Dipterocarpus, together with palynological evidence, indicates unequivocally that a tropical climate and tropical rain forest occurred in Zhangpu during the middle Miocene, warmer and more humid than at the present day. The palaeobiogeography of Dipterocarpus is reviewed.