Neogene Fossil Woods Of Yunnan Province And Their Palaeoclimate Implications

191 specimens of fossil woods collected from Neogene sediments of Yunnan Province are studied. Seven taxa are identified and described in details. Among of them, three new species are established as Ericaceoxylon longlingense, Ericaceoxylon hymenanthesoides and Vacciniaceoxylon vacciniumoides. P alaeoenvironment and palaeoclimate of three localities are discussed with the reference to the ecological comparisons of extant taxa using the nearest living relative approach. Identified taxa and their characters as follows:Pinus armandii Franchet: Normal vertical and horizontal resin canals with thin-walled epithelial cells present. Cross-fields pitting window-like. Ray tracheid walls smooth or with minute dentations.Tsuga dumosa Richer: The regular presence of ray tracheids. Axial parenchyma cells rare and distribute in the boundaries of growth rings. Cross-field pitting cupressoid with 1-5 pits. Tori extensions present on pit membrane.Taxodioxylon cryptomeripsoides Schonfeld: Growth rings distinct, transition from early wood to late wood more or less abrupt. Bordered pits on tracheids radial walls mostly uni-seriate rows. Rays entirely parenchymatous, uni-serate; horizontal and tangential walls of ray cells smooth and thin. Cross-field pitting taxodoid with 1-4 pits. Axial parenchymatous cells abundant, diffusely distributed as solitary cells or occasionally as tangentially aligned pairs.Taxodioxylon cunninghamioides Watari: Growth rings distinct, transition from early wood to late wood more or less abrupt. Bordered pits on tracheids radial walls uni-seriate and bi-seriate rows. R ays e ntirely p arenchymatous, u ni-serate; h orizontal a nd t angential w alls o f r ay c ells a re smooth and thin. Cross-field pitting taxodoid with 1-4 pits. Axial parenchymatous cells abundant, diffusely distributed as solitary cells or occasionally as tangentially aligned pairs.Ericaceoxylon longlingense sp. nov.: Growth rings boundaries distinct. Wood diffuse-porous. Vessels solitary with angular outline; perforation plates scalariform; intervessel pits and vessel-ray pitting alternate to scalariform; helical thickenings only in vessel elements tails. Fibres with thin-to thick-walled. Axial parenchyma rare, scanty paratracheal. Ray width 1-6 cells; Body ray cells procumbent with mostly 2-4 rows of upright and /or sqaure marginal cells.Ericaceoxylon hymenanthesoides sp. nov.: Growth rings boundaries distinct. Wood semi-ring-porous. Vessels solitary with angular outline; perforation plates scalariform; intervessel pits and vessel-ray pitting opposite; helical thickenings throughout body of vessel elements. Fibres with thin- to thick-walled. Axial parenchyma rare, scanty paratracheal. Ray width 1-4 cells; Body ray cells procumbent with 1-9 rows of upright and /or square marginal cells.Ericaceoxylon cf. hymenanthesoides: Growth rings boundaries distinct. Wood semi-ring-porous; Vessels solitary with angular outline; perforation plates scalariform; intervessel pits and vessel-ray pitting opposite or opposite to scalarifonn; helical thickenings in vessel elements present. Fibres with thin- to thick-walled. Ray width 1-3 cells; Body ray cells procumbent with 1-9 rows of upright and /or square.Vacciniaceoxylon vacciniumoides sp. nov.: Growth rings boundaries indistinct. Wood semi-ring-porous; Vessels solitary with angular outline; perforation plates reticulate and scalariform; intervessel pits and vessel-ray pitting alternate; helical thickenings throughout body of vessel elements. Fibres with thin- to thick-walled, bordered pits distinct. Axial parenchyma rare, diffuse and scanty paratracheal. Ray width 1-4 cells; Body ray cells procumbent with 1-4 rows of upright and /or square marginal cells.There are 2 taxa, Taxodioxylon cryptomeripsoides Schonfeld and Taxodioxylon cunninghamioides in Ltihe locality. The existence of two taxa of Taxodiceae reflects a warm-humid local environment under subtropical climate during Late Miocene.There are 4 taxa, Pinus armandii, Ericaceoxylon longlingense, Ericaceoxylon hymenan...