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Simple Summary: Two fruit fossil species of Ceratophyllum L. are discovered from South China, namely C. cf. muricatum Chamisso from the upper Eocene of the Maoming Basin, Guangdong, and C. demersum L. from the Miocene of the Guiping Basin, Guangxi. Our findings provide evidence for the distribution of Ceratophyllum in South China in the late Eocene, and its wide expansion in subtropical China during the Miocene. Ceratophyllum L. is a cosmopolitan genus of perennial aquatic herbs that occur in quiet freshwaters. Fossils of this genus have been widely reported from the Northern Hemisphere, most of them occurring in the temperate zone. Here, we describe two species of fossil fruits discovered from subtropical areas of China. The fossil fruit discovered from the upper Eocene Huangniuling Formation of the Maoming Basin is designated as C. cf. muricatum Chamisso, and fruits discovered from the Miocene Erzitang Formation of the Guiping Basin are assigned to the extant species C. demersum L. The discovery of these two fossil species indicates that Ceratophyllum had spread to South China by the late Eocene and their distribution expanded in subtropical China during the Miocene. [ABSTRACT FROM AUTHOR]

PREMISE OF THE STUDY: Phylogenetic analysis of DNA sequence data has changed our view on the evolution and systematics of plant taxa. Based on the phylogenetic analysis of several molecular markers, fruit anatomy, and pollen morphology, the genera Altingia and Semiliquidambar were formally transferred to the genus Liquidambar. The new species of Liquidambar from the Eocene of South China significantly extends our knowledge of the variability of the morphological characters of this genus in the geological past. Fossil leaves in conjunction with data on the associated reproductive structures allow us to make inferences about patterns in the evolutionary history of Liquidambar. METHODS: Fossil leaves and associated reproductive structures preserved as impressions were described and compared with the corresponding organs of extant and fossil relatives. The morphological variation of numerous leaves was examined by stereomicroscopy. KEY RESULTS: Liquidambar maomingensis sp. nov. is characterized by polymorphic leaves including both palmately lobed and unlobed leaves. This study presents the first observations of such dimorphism in the fossil record of Liquidambar leaves. Two distinct leaf groups are interpreted as sun and shade leaves. CONCLUSIONS: The fossil leaves and associated infructescences from Maoming probably belong to the same plant. The occurrence of fossil leaves similar to those of extant species previously considered with in Semiliquidambar and Liquidambar with the associated infructescences close to those of Altingia provide paleobotanical evidence that justifies combining the genera Liquidambar, Altingia, and Semiliquidambar into the single genus Liquidambar as recently proposed based on molecular markers. [ABSTRACT FROM AUTHOR]

* Premise of the study: Dipterocarps are the representative component of tropical rain forests in Southeast Asia and hold important economic and ecological significance, but their origin and migration are controversial. Information on dipterocarpaceous fossils, particularly the more convincing reproductive structures, not only can improve the phylogenetic and phytogeographic studies of this family, but also provide important information for reconstructing paleoclimate. * Methods: Morphologically preserved winged fruits and associated leaves were collected from the Late Eocene Huangniuling Formation, Maoming Basin, South China. We determined their taxonomic positions based on comparative morphology with similar extant and fossil specimens and discuss their phytogeographic and paleoclimatic implications by consulting the distribution and habitat of fossil and modern populations. * Key results: The Late Eocene winged fruits are attributed to Shorea Roxburgh ex Gaertner (Dipterocarpaceae) as Shorea maomingensis sp. nov. The associated leaves are recognized as Shorea sp. based on leaf architecture, and they are likely to be conspecific with the winged fruits. * Conclusions: The discovery of dipterocarps indicates that they had arrived in tropical and humid South China by the Late Eocene. Dipterocarps including Shorea exhibit a wide range of physiological tolerance to climate; palynological analysis suggests an increase in aridity and seasonality in the Maoming Basin from the Late Eocene. Dipterocarps became adapted to this seasonal climate from the Late Eocene to Early Miocene, expanded northward in the climatic optimum of the Middle Miocene, and declined and gradually disappeared from the southeastern part of the continent from the Late Miocene. [ABSTRACT FROM AUTHOR]

[Display omitted] • Valuable insight into impact of past climate changes on range dynamics of M. insignis. • Additional evidence of glacial expansion for montane species at low latitudes. • Offer protection strategy for low latitudes montane species respond to climate change. The Pleistocene Epoch, marked by significant climatic fluctuations and glaciations, profoundly impacted plant populations. However, our understanding of the influences of last glaciations on tropical-subtropical flora and vegetation remains limited due to insufficient data. Here, we present mummified wood of Magnolia insignis (Wall.) Bl. from the Upper Pleistocene (33–30 ka cal. BP) of Maoming, South China, providing direct evidence of a broader historical range for this species during the period prior to the LGM in the last glaciation. Combining these findings with results from MaxEnt modeling, we demonstrate an expanded range of M. insignis into lower latitudes during last glaciation with subsequent interglacial contraction. This represents the second documented case of such a scenario for a cold-tolerant high-elevation plant species at low latitudes. The results of MaxEnt modeling and a comparison of climatic data across different time periods indicate that the contraction of M. insignis from the Maoming and other low latitude regions of East Asia was driven by the increase in summer temperatures during Holocene. This study not only sheds light on the responses of cold-adapted mountainous species at low latitudes of East Asia to last glaciation, but also justifies the importance of their protection in the view of nowadays and future climate changes. [ABSTRACT FROM AUTHOR]