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Nothotsuga is a monotypic genus of Pinaceae endemic to southern China today. Molecular data indicate that Nothotsuga split from Tsuga during the Palaeogene with the earliest fossils from the upper ...

Numerous pollens and a few wood fossils with probable affinity to Podocarpus L’Heritier ex Persoon have been discovered from China. However, the leaf fossils of Podocarpus were not well documented....

Fossil leaves of Populus L. (Salicaceae Mirb.) were widely reported in the North Hemisphere during the Cenozoic. However, most of them are leaf impressions without details of cuticles or only preserved as tiny cuticle fragments. Here, we describe several fossil leaves of Populus with fine cuticular structures from the upper Pliocene of Tengchong, western Yunnan, China. The leaves have ovate, rhombic-ovate to orbicular leaf shape with long petioles, pinnate venation, rounded to cuneate bases, acuminate apices and serrate margins. They are pilose bilaterally with multicellular trichome bases and hypostomatic with paracytic stomata. According to the gross morphology and cuticle structures, the present fossils mostly resemble the extant species P. rotundifolia Griff. except that the fossils have denser trichome bases, and are therefore tentatively assigned to Populus cf. rotundifolia Griff. Nowadays, P. rotundifolia is distributed at mountain slopes above an elevation of 2000 m a.s.l. The present new finding indicates that western Yunnan might have approached its present height at least by the late Pliocene. Recent phylogenetic study proposed that the divergence of P. rotundifolia from P. davidiana Dode occurred at the Pleistocene (Calabrian, ca. 0.88 Ma). However, our fossil occurrence implies that such a divergence might have occurred at least by the late Pliocene (3.3–2.8 Ma), much earlier than the molecular estimation. In addition, the Hengduan Mountainous Region might be the species differentiation center of P. rotundifolia from P. davidiana based on their modern distributions and the present fossil occurrence.

The fossil records of Pinus L. are abundant since the Late Cretaceous, especially for the subgenus Pinus L. (the hard pines). However, those of the subgenus Strobus (D. Don) Lemmon (the white or so...

Premise of research. Cyclocarya Iljinskaya (Juglandaceae) is a genus with a single living species that is endemic to central and south China. The genus has an abundant North American and Eurasian fossil record from the Paleocene to the Pliocene, documenting its spread across Europe to western Siberia during the Oligocene and its arrival in Japan by the Miocene. However, there have been no fossil occurrences of Cyclocarya near its modern distribution. In this study, we describe a new species of Cyclocarya from the upper Miocene Nanlin Formation in Lianghe County, western Yunnan Province, southwest China, and discuss its biogeographic implications.Methodology. We examined the fossil fruit using LM and SEM, and we compared its morphology with fruits of fossil Cyclocarya and extant Cyclocarya paliurus (Batalin) Iljinsk.Pivotal results. The fossil fruit of Cyclocarya simipaliurus sp. nov. consists of a small nutlet that is surrounded by a circular and flange-like wing. The nutlet is circular in plan view and o...

Abundant fossil records indicate that the genus Smilax L was widely distributed in North America and Europe during the Paleogene and thrived in the Miocene. However, since the early Pliocene, the fossil occurrence of Smilax has become very rare. In this study, we describe three leaf taxa of Smilax from the upper Pliocene of West Yunnan, Southwest China based on their leaf architecture and cuticle features. Smilax tengchongensis sp. nov. and Smilax cf. bracteata Presl differ from each other both in leaf shape and cuticle features. The leaves of Smilax sp. possess a different shape and venation but share similar cuticle features with those of S. tengchongensis sp. nov. The morphological diversity of our fossils indicates that a warm and humid climate with a multilayered structure existed in the Pliocene forests of West Yunnan. Moreover, recent molecular studies indicate that both New World and Old World species of Smilax exhibited an intercontinental disjunct distribution via the Beringia land bridge between East Asia and North America. However, this biogeographic disjunction is not well demonstrated by the fossil records as a result of inadequate paleobotanical data. (C) 2017 Elsevier B.V. All rights reserved.

Mesozoic strata are well developed in Huating County, Gansu Province, Northwest China. However, few megafossil plants from this region have been reported in detail and thus the fossil plant diversify is unclear. In this study, the new conifer species Storgaardia gansuensis n. sp. is described based on recent collections from Aalenian to Bajocian at Xihua coal mine of Huating, Gansu Province, China. The specimens are characterized by leafy shoots alternately or sub-oppositely arranged, linear to linear-lanceolate, hypostomatic leaves with thin cuticles. On the basis of the epidermal structures of St. gansuensis and comparison with extant conifers, we propose that Storgaardia is allied with Amentotaxus of Taxaceae. The paleogeographic distribution suggests that Storgaardia probably originated in the Late Triassic in East Asia, and later spread from Asia to Europe and further to East Greenland. The paleogeographic distribution of Storgaardia and associated plants indicates that they lived under a warm-temperate to temperate climate during the Middle Jurassic in East Gansu Province, Northwest China. 2016 Elsevier B.V. and Nanjing Institute of Geology and Palaeontology, CAS. All rights reserved.

Phylogenetic analyses indicate that the genus Podocarpus diverged around the Cretaceous/Paleogene boundary, and two monophyletic subgenera Podocarpus and Foliolatus had differentiated during the Paleogene. Most of described fossil remains were related to the subgenus Podocarpus, but those of the subgenus Foliolatus have not been well documented. Here, we described a new species of Podocarpus, P. yunnanensis sp. nov., and P. cf. forrestii from the lower Pliocene of western Yunnan, China based on a detailed comparisons of gross leaf morphology and cuticular structures between the studied fossils and extant Podocarpus. These two fossil taxa together with P. pliomacrophyllus H. Chen et J.Y. Wu from the same horizon, revealed a thriving of Podocarpus in western Yunnan during the Pliocene. For the subgenus Foliolatus, its early representatives might originate from Australasia and spread northward to northeastern India at least during the late Oligocene. The Neriifolius subclade within the subgenus is much older than the estimate of molecular clock studies, and the Indochinese subclade is probably derived from a rapid diversification driven by the continuous uplift of Hengduan Mountains (HDM) with the accompanying climate fluctuations since the late Miocene. Moreover, the thriving of Podocarpus in the Pliocene of western Yunnan reveals a warm and humid climate during that period. The Pleistocene glaciation and the geographic barriers posted by the HDM might contribute to the modern distribution of Podocarpus in South China and Indochina Peninsula.

Six well-preserved seed cones of Tsuga with fine bract-scale complexes were discovered from the late Miocene (Tortonian; 9.2–10.8 Ma) deposits of the Shengxian Formation at the border of Ninghai and Tiantai County, Zhejiang Province, eastern China. The fossil cones possess ovate to elliptic shape, spirally arranged and obovate-orbicular ovuliferous scales, and cuneate-rhombic bracts hidden behind the scales with 2-lobed apex. Based on detailed comparison with extant and fossil cones of Tsuga, the present fossils are assigned to Tsuga cf. dumosa (D. Don) Eichler. The discovery of the fossil cones indicate that Tsuga had a wider distribution during the late Miocene than at the present. The increase of the difference in temperature between the coldest and warmest months since the late Miocene had forced Tsuga to retreat from eastern Zhejiang.

Fossil Ginkgophyta are one of the most widely used indicators for estimating the paleoatmospheric CO2 levels from the Triassic to present day. There are quite a few CO2 estimates for the Triassic to Jurassic interval; however, the data from China are still limited. In this study, two fossil Ginkgoites species, Ginkgoites magnifolius Du Toit and Ginkgoites obrutschewii (Seward) Seward, are described based on recent collections from the Upper Triassic and Middle Jurassic in Huating County, Gansu Province, Northwest China. The fossil leaf morphology and epidermal structure were studied and the stomatal parameters were analyzed for the reconstruction of paleoatmospheric CO2 concentrations. The paleoatmospheric CO2 concentration during the Late Triassic of China is estimated for the first time based on fossil material from Gansu. Our fossils yield paleo-CO2 values of 1962 ppmv in the Late Triassic and 1320 ppmv in the Middle Jurassic. Compared with previous estimates of atmospheric CO2 concentration based on stomatal parameter of fossil Ginkgo/Ginkgoites from Northwest China, the change of Jurassic paleo-CO2 levels accord with the trend of CO2 concentration proposed by GEOCARB III and Crustal Production models. The results demonstrate that the paleo-CO2 of the Late Triassic was higher than that of the Early to Middle Jurassic; but an increasing trend of paleo-CO2 could be detected from the Early to the Middle Jurassic. However, the GEOCARBSULF model indicates a decreasing trend during this interval. Therefore, the present data provide an independent check for the paleo-CO2 value estimation based on isotopic analysis.

Two fossil leaves identified as Castanopsis presclerophylla n. sp. collected from a diatomite bed in the upper Pliocene (3.3–2.8 Ma) in Tengchong County, Yunnan Province, Southwest China, are characterized by elliptic laminar shapes with acuminate apex, convex base, simple trichome bases and cyclocytic stomata. The cuticles of extant leaves from six selected Castanopsis species that are similar to the Pliocene fossil leaves in laminar shape were examined in detail for the comparison. Based on the analysis of leaf architecture and cuticular characteristics, the present fossil leaves most closely resemble the extant leaves of Castanopsis sclerophylla (Lindl.) Schott., which prefers a subtropical climate. The published fossil records of Castanopsis also indicate that it was once widely distributed in North America, Europe and Asia before the Pliocene, and then rapidly retreated to the East and Southeast Asia as a result of the Pleistocene glaciation.

A long shoot with needles and two immature seed cones, and some isolated organs of shoot, needles and seed cones from the late Miocene Shengxian Formation in Zhejiang Province, East China are described. A detailed comparison of the gross morphology and cuticle micromorphology of needles and seed cones with previously published Cenozoic fossils and related extant pine species reveals that the present fossils can be identified as a new species, Pinus premassoniana sp. nov., which has the closest affinity with extant Pinus massoniana. A pollen cone with copious bisaccate pollen grains from the same locality is identified as an indeterminate species of subgenus Pinus. The pollen grains show a verrucate external sculpture on the corpus and sacci and an alveolae internal structure in the sacci. The fossil needle cuticles and pollen cone of the genus Pinus from China are reported for the first time. The modern distribution indicates that P. premassoniana sp. nov. should also live under a warm and humid climate. Hitherto, there is no any reliable fossil record that has an affinity with the extant P. massoniana. The occurrence of the present fossils suggests that P. premassoniana has existed in East China since at least in the late Miocene.

Two types of fronds belonging to a new species, Drynaria dimorpha sp. nov., are described from the upper Pliocene Mangbang Formation in western Yunnan, southwestern China. The base frond is lobate and the lobes are incised up to 2/3 or more of the width. The foliage frond is preserved as individual fertile or sterile pinnae with serrated margin and constricted basal part. Circular son are arranged in one row on either side of the primary vein. In situ spores are monolete and planoconvex, elliptical in polar view and bean-shaped in equatorial view. A detailed morphological comparison suggests that none of the previously described drynarioid fossils and extant species is in accord with the present ferns. The discovery of this new fern indicates that a developed humus-collecting structure of Drynaria had existed and a species-level radiation of this genus had taken place at least by the late Pliocene. (C) 2012 Elsevier B.V. All rights reserved.

Smilax tiantaiensis sp. nov. is described from the Late Miocene Shenxian Formation in Zhejiang Province, East China based on five fossil leaves with fine venation and well preserved cuticles. The fossil leaves are characterized by an ovate shape, entire margin, mucronate apex, rounded base, five primary basal acrodromous veins with reticulate venation in between; leaves hypostomatic, anticlinal walls undulated and stomatal apparatus anomocytic. The fossils have been compared with extant and other fossil species hitherto described in this genus. Some fossil stromata, hyphae and spores identified as Callimothallus pertusus Dilcher (Microthyriaceae) were discovered on the both epidermides of S. tiantaiensis. The climbing habit of Smilax and the presence of the epiphyllous fungus of C. pertusus on the fossil leaves may indicate that the multistratified forest was growing under a humid climate during the Miocene in Zhejiang. (C) 2011 Elsevier B.V. All rights reserved.

Neogene climates and vegetation history of western Yunnan are reconstructed on the basis of known fossil plants using the Coexistence Approach (CA) and Leaf Margin Analysis (LMA). Four Neogene leaf floras from Tengchong, Jianchuan and Eryuan in southwestern China are analyzed by the CA, and the paleoclimatic data of one Miocene carpoflora from Longling and three Pliocene palynofloras from Longling, Yangyi and Eryuan are used for comparison. The Miocene vegetation of the whole of West Yunnan is subtropical evergreen broad-leaved forest, and a similar mean annual precipitation is inferred for Tengchong, Longling and Jianchuan. However, by the Late Pliocene a large difference in vegetation occurred between the two slopes of Gaoligong Mountain, western Yunnan. The region of Tengchong retained a subtropical evergreen broad-leaved forest vegetation, whereas in Yangyi and Eryuan a vertical vegetation zonation had developed, which consists, in ascending order, of humid evergreen broad-leaved, needle and broad-leaved mixed evergreen, and coniferous forests. Distinctively, the Late Pliocene vegetational patterns of West Yunnan were already very similar to those of the present, and the Pliocene mean annual precipitation in Tengchong was markedly higher than that of Yangyi and Eryuan. Considering that the overall vegetation of West Yunnan and the precipitation at Yangyi and Eryuan have undergone no distinct change since the Late Pliocene, we conclude that the Hengduan Mountains on the northern boundary of West Yunnan must have arisen after the Miocene and approached their highest elevation before the Late Pliocene. Furthermore, the fact of the eastern portion of the Tibetan Plateau underwent a slight uplift after the Late Pliocene is also supported. (C) 2010 Elsevier B.V. All rights reserved.

The cuticular d13C values and stomatal parameters (stomatal density and stomatal index: SD and SI) of two Betulaceae species, Betula mioluminifera Hu et Chaney and Carpinus miofangiana Nathorst, from a suite of superposed horizons in West Yunnan, southwestern China, were measured in order to recover Late Pliocene CO2 levels. Correlations are given for d13C, SD, epidermal cell density (ECD), and SI. d13C reveals a positive trend with the SD and SI in the two species, and such a positive correlation can also be observed between the d13C and ECD in C. miofangiana. However, d13C has a slightly negative correlation with the ECD in B. mioluminifera (R2= 0.06), possibly influenced by their different genotypes. Reflecting the changes through time, the d13C values of B. mioluminifera and C. miofangiana significantly increase with high determination coefficients (R2= 0.67 and R2= 0.65, respectively), as do SD (R2= 0.66 and R2= 0.51, respectively) and SI (R2= 0.50 and R2= 0.79, respectively). Research on extant B. luminifera and C. fangiana shows that the SD and especially SI, exhibit a prominent negative correlation with CO2 concentration. Pliocene CO2 levels are reconstructed as 381.5-439.4 ppmv and 377.8-472.3 ppmv, respectively, based on comparisons of the two fossil species with their nearest living equivalent (NLE) species. The significant positive trends of the d13C, SD and SI with ascending position of the fossils in the section indicate that the atmospheric CO2 levels declined in the Late Pliocene (3.30-2.83 Ma). Furthermore, the calculated CO2 levels are higher than in other studies and probably demonstrate that local CO2 enrichment can be caused by frequent volcanic eruptions over a long time scale

Platycladus Spach is native to Central China, but its natural occurrences are very difficult to establish. According to molecular phylogenetic data, this genus might have originated since the Oligocene, but no fossil record has been reported. Here, we describe eight foliage branches from the upper Miocene in western Yunnan, Southwest China as a new species, P. yunnanensis sp. nov., which is characterized by foliage branches spread in flattened sprays, and leaves decussate, imbricate, scale-like and dimorphic. The leaves are amphistomatic, and the stomata are elliptical or oblong, haplocheilic, and monocyclic type. Based on a detailed comparison with the extant genera of Cupressaceae sensu lato, our fossils are classified into the genus Platycladus. The occurrence of P. yunnanensis sp. nov. indicates that this genus had a more southernly natural distribution in the late Miocene than at present. Molecular phylogeny and fossil records support a pre-Oligocene common ancestor for the genera Platycladus, Microbiota and Calocedrus. The separation of the three taxa was most likely caused by the arid belt across Central China during the Oligocene. In addition, the cooling down of the global temperature and the strengthening of Asian monsoon since the Miocene will further promote the migration of these genera.