Fossil reproductive structure from the Eocene of the Changchang Basin (Hainan Island,South China) is recognized as Chaneya hainanensis sp.nov.This new species is characterized by persistent corolla of five obovate petals with three subparallel primary venation linked by arching secondary veins,circular central disk bearing two orbicular ovaries or fruit bodies.This discovery confirms the presence of the extinct fruit genus Chaneya in low-latitude tropical area,providing significant fossil evidence for investigating the origin,migration,and phytogeography of this genus and discussing the Tertiary floristic exchanges among North America,eastern Asia,and Europe.Considering the distribution of this genus and its extant relatives and the climate changes during the Cenozoic,we hypothesize that Chaneya was a widespread tropical or subtropical taxon,but,with climate cooling,became extinct in northern latitudes and evolved into Picrasma (Simaroubaceae) and Rutaceae mainly in modern tropics and subtropics.
Modern palms are diverse and widespread in the tropics and subtropics,especially the tropical rainforests.However,most fossil palm records have been reported from regions of relatively higher latitude.In this paper seven species of coryphoid palm from the Eocene Changchang Basin of Hainan Island of South China are reported.These are Sabalites asymmetricus sp.nov.,S.robustus sp.nov.,S.tenufolius sp.nov.,S.szei Guo,S.changchagnensis Guo,Livistona sp.,and Amesoneuron sp.According to leaf morphological characteristics,they can be classified as members of the subfamily Coryphoideae.In extant flora of Hainan Island,only three species of Livistona have costapalmate leaves.These palm fossils indicate that,during the Eocene,flora in Hainan Island included a diversity of coryphoid palms,which have some bearings on the reconstruction of the palaeoclimate of South China.
