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Although many fossil and molecular data suggest migrations from Malesia and Asia to Australia appear to dominate floristic exchange between Australian and Asian rainforests, evidence is emerging that demonstrate dispersal of plant groups from Australia to Asia. In this paper, a new species Agathis ledongensis sp. nov. is described on the basis of silicified wood from the late Oligocene–early Miocene of the Qiutangling Formation in Ledong, Hainan Island, South China. It is the first fossil record of Agathis in the Northern Hemisphere, and the only known fossil evidence of its dispersal outside of Gondwana. The close affinity of the fossil wood from Ledong with the genus Agathis was confirmed by comparing quantitative traits in 31 wood samples of 20 species representing all three extant genera of the Araucariaceae. The percentage of tracheids with uniseriate pitting on radial walls is shown as an additional diagnostic trait for separating Agathis and Wollemia from Araucaria. The wood of Agathis ledongensis provides evidence for the dispersal of this important plant group from Australia, or another Gondwanan terrane, to eastern Asia based on reliable fossil data. It records the occurrence of this genus in Hainan Island by the early Miocene, i.e. at the beginning of the formation of the island chains between Australia and the South-East Asia and thus the provision of a land migration route. As the land routes between these continents were restricted at that time, the migration of Agathis to Malesia and Asia was presumably facilitated by long-distance dispersal of its winged seeds by wind. [ABSTRACT FROM AUTHOR]

Premise of research. Petrified wood has never been described from the Miocene of South China, and the Miocene flora from this region is also poorly known. The fabaceous fossil wood introduced in this article not only contributes to the scant knowledge of petrified woods in South China but also provides significant fossil evidence to study the Miocene floristic diversity in the modern tropical area of China. Methodology. Anatomically preserved petrified woods collected from the Early-Middle Miocene of Jialai-Nanbao Basin, Hainan Island, were sectioned in accordance with standard methods of cutting, grinding, and polishing. We determined their taxonomic positions based on comparative work in anatomy with similar extant and fossil wood slides. Pivotal results. Woods in two different degrees of fossilization represent the same species and correspond closely to wood structure of modern genera Afzelia and Intsia and their fossil counterparts Pahudioxylon. The wood is recognized as Pahudioxylon bankurensis Chowdhury, Ghosh, et Kazmi, which had been reported from the Neogene of India. Six species of Pahudioxylon (P. sahnii Ghosh et Kazmi, P. deomaliense Prakash, P. welkitii Lemoigne et Beauchamp, P. assamicum Prakash et Tripathi, P. indicum Prakash, and P. bengalensis Ghosh et Roy) have been reconsidered as its synonyms. Conclusions. This studied Pahudioxylon species represents the first occurrence of this genus in China as well as rarely reported Miocene plant megafossils in South China. Several previously described Pahudioxylon species should be merged into P. bankurensis. [ABSTRACT FROM AUTHOR]

Fossil cytoplasm is attracting increasing attention in the fossil record, and ultrastructures in plant cells are revealing new aspects of ancient life. Chloroplasts have been previously reported in fossil plants in the US, Canada, and Russia. Here, we report on fossil chloroplasts with internal ultrastructure in a fossil leaf of Nelumbo changchangensis from the Eocene of Hainan Island, South China. The chloroplasts in this fossil demonstrate great similarity to their counterparts in living relative as well as those in the previous reports. The well-preserved chloroplasts in plant fossils call for more attention to ultrastructures and the fossilizing mechanisms of cytoplasm. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Abstract: The modern distribution centre of the genus Craigia is situated in South China and adjacent northernmost Vietnam, but it was widely distributed in Europe, North America and East Asia during the Tertiary. Up to now, the genus Craigia includes only two extant and two fossil species. Based on a detailed study of the fossil material from the coal-bearing deposits of the Changchang Formation (Eocene) from the Changchang Basin of Hainan Island, China, Craigia hainanensis sp. nov. is established. This is the first fossil record of Craigia in its modern distribution centre which provides a new data on the origin and phytogeographic history of this genus. The distribution of extant and fossil Craigia in North America, Europe, Central and East Asia suggests that the Far East of Russia is a possible centre of origin of Craigia where the fossil record of this genus goes back to the Paleocene. During the Eocence global warming event, Craigia had dispersed rapidly to North America, Spitzbergen, East and Central Asia, and reached its modern distribution centre in South China no later than in the early Late Eocene. During the Oligocene and Neogene this genus continued to spread over Asia and further dispersed to Europe. [Copyright &y& Elsevier]

Abstract: A new species of Nelumbo Adanson is described from the Eocene of the Changchang Basin, Hainan Island, South China. This is the first comprehensive report on a fossil Nelumbo species from the Eocene of the Changchang Basin, Hainan Island. The co-occurrence of fruits, tubers, rhizomes with numerous adventitious roots, leaves, and receptacles indicates that the plants grew where they are preserved. These specimens, combined with palynological assemblage and other macrofossils, indicate a tropical or subtropical humid climate in the Changchang Basin from the late early Eocene to early late Eocene. [Copyright &y& Elsevier]

Abstract Bartonian-aged samples from the Changchang Formation (Hainan) have been palynologically analyzed using light microscopy (LM) and scanning electron microscopy (SEM). The presence of cf. Laurelia -type pollen demonstrates a wide geographical range for this family during the Eocene. A particular paleobiogeographic pattern, suggesting Eurasia as the place of origin, can be seen from six pollen taxa: (1) A Flueggea -type, together with previously found European Flueggea fossils, (2) a Nyssa -type closely resembling the extant Nyssa sinensis and upper Eocene Nyssa pollen from Europe, (3) three Symplocos- types, which are closely related to the early diverging Symplocos subgenus Palura, resemble upper Eocene Symplocos pollen from Germany, and (4) a Cornus- type belonging to the "blue-or-white-fruited clade," like several Cornus fossils from Europe. In contrast, an Asian paleobiogeographic pattern can be seen from six Hainan taxa: (1) Two Phyllanthus subgen. Eriococcus/Isocladus -types, here described for the first time, that, so far, occur only in China, (2) a Lagerstroemia- type that resembles pollen of the Miocene Lagerstroemia cathayensis from China and pollen of two extant deciduous Lagerstroemia taxa, (3) a Juglans -type that is assumed to belong to Juglans section Cardiocaryon , and (4) two Dipterocarpaceae pollen types (cf. Dipterocarpus and cf. Dryobalanops) that are here described for the first time from Eocene strata outside India. A much wider distribution can be observed with the Fagus -type pollen closely resembling pollen of the extant Fagus "subgenus Engleriana" and Paleogene Fagus pollen from Greenland and Canada, suggesting an amphipacific distribution of an ancient Fagus "Engleriana lineage" during the Eocene. The Craigia -type corroborates the presence of Craigia diaspores from the Changchang Formation and two Mortoniodendron -types reveal a particular paleobiogeographical history; extant Mortoniodendron grows in Central America and is known there since the Miocene. However, Eocene Mortoniodendron -type pollen from Europe and now Hainan indicate a far wider distribution of this genus. The two Iodes types, one resembling African/Madagascar taxa and one a Melanesian taxon, suggest that the Old World disjunction of Iodes in Africa/Madagascar and SE Asia is a Paleogene relict, whereas the third Icacinaceae taxon resembles two genera of the Mappia/Nothapodytes clade, where Mappia occurs today in Central America and Nothapodytes in SE Asia. Highlights • Eocene pollen from Hainan were analyzed with LM and SEM. • Eocene Eurasian populations of Cornus , Juglans , Nyssa, and Symplocos existed. • Dipterocarps, Phyllanthus subgen. Eriococcus/Isocladus and Lagerstroemia are Asian. • Laurelia, Flueggea, Iodes , and Trachycarpeae were widespread in the Eocene. [ABSTRACT FROM AUTHOR]

The middle Eocene (Lutetian–Bartonian, 48.6–37.2 Ma) near-equatorial megafossil flora from swamp and lacustrine facies of the lower Changchang Formation, Hainan Island, South China (19.631463°N, 110.445049°E) is highly diverse (> 200 taxa) dominated by an unusual mixture of angiosperms typical of modern temperate, subtropical and tropical evergreen and deciduous forms. It is also rich in palms. Multivariate analysis of the architecture of minimally transported woody dicot leaves reveals a mean annual air temperature (MAT) of ~ 22 ± 4.7 °C with a marked thermal seasonality range of ~ 21 °C. The year-round humid climate lacked any monsoonal signature. The overall climate signal is compatible with the growth characteristics exhibited by fossil wood, but is warmer than the climate signal derived from pollen and spores using Co-existence Analysis. Corrections for possible palaeoelevation of the basin bring the megafossil-derived MAT estimate in line with 54–52 Ma sea surface and soil temperatures obtained from the Gulf Coast, USA, (palaeolatitude ~ 30°N) using multiple geochemical proxies and supports the claim that the low latitude Eocene climate was not uniformly warm. This challenges previous conclusions based on ∂ 18 O analysis of unaltered calcareous microfossils. Our air temperature data also adds to the challenge of understanding heat transport away from the equator to higher latitudes during ‘hothouse’ climate regimes. [ABSTRACT FROM AUTHOR]