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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.

The first megafossil record of the genus Neolepisorus Ching from the late Miocene of Yunnan Province, SW China, is reported. Neolepisorus chingii sp. nov. is represented by a simple fertile frond with one line exindusiate, elliptic-fusiform sori along the lower part of the midrib, and a basal contractive sterile frond with a sinuolate margin. The venation is characterized by a strong midrib, prominent zigzagging lateral veins, and reticulate higher order veins with free-ending veinlets (simple or forked once). The combination of these characters confirms the genus Neolepisorus (Polypodiaceae), now distributed in subtropical Southeast Asia, except for one species, which inhabits Madagascar of tropical Africa. It has a distribution center south of the Yangtze River in China. So far, no megafossil assigned to Neolepisorus has been reported, and the occurrence of Neolepisorus chingii in SW China associated with other types of fern occurrence adds increased evidence of fern radiation during the Neogene in Yunnan Province in response to the uplift of the Tibetan Plateau.

The fossil record of Quercus subgenus Cyclobalanopsis can be traced back to the Late Eocene of eastern Asia based on fossil foliage and acorns. We refer new occurrences of leaf and acorn fossils from the upper Miocene of Tiantai, eastern Zhejiang, China, to two new species, Quercus paraglauca sp. nov. and Quercus heterobracteolata sp. nov.. Q. heterobracteolata represents the earliest confirmed fossil acorn of the subgenus Cyclobalanopsis in China. A review of other occurrences reported in the literature reveals that the divergence of subgenus Cyclobalanopsis occurred not later than the Eocene, and in the Miocene Cyclobalanopsis was already widely distributed. Comparisons of cuticular structure between Q. paraglauca and its nearest living relative species (NLR) Q. glauca suggest that: 1) atmospheric CO2 concentration in the late Miocene was ca. 400 ppmv, i.e. higher than the present natural CO2 concentration, eliminating the industrial influence; 2) the Q. glauca trichome base density is sensitive to the environmental changes; and 3) the late Miocene climate of Zhejiang (eastern China) was warmer and more humid than today.

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.

Compressions of leafy twigs, pollen cones and seed cones of Athrotaxites yumenensis C. Dong et B.N. Sun sp. nov. (Cupressaceae) are abundant in certain layers of the Lower Cretaceous Zhonggou Formation in western Gansu Province, northwestern China. The leafy branches are stiff and ascending. The leaves are scale-like, spirally arranged and closely appressed to the stem. The seed cones are located terminally, globular, with 8-11 helically arranged bract-scale complexes. The bracts are intimately fused with, and more massive than, the seed-bearing portion, and each scale has two seeds. The seeds are oval, 0.9 -1.1 mm long and 1 mm wide with two wings derived from the seed coat. A single pollen cone occurs at the ends of the ordinary branches with 10-16 microsporophylls. The microsporophylls are wedge-shaped and spirally arranged. Terminal microsporophylls fall away from the cone axis after pollen dispersal. The pollen sacs are ovate and produced more than 20 pollen grains per sac. The pollen grains are spherical, lack air bladders and have small germinal papilla and pores. Compared to the extant Tasmanian genus Athrotaxis in morphological, structural and cuticular features of leafy shoots, as well as seed cones and pollen cones, the study fossil consistently shares many characteristics with the extant genus, especially the extant species Athrotaxis cupressoides, but differs from it in other aspects; thus, it has been placed in a new genus. The similar characteristics, however, suggest that the fossil has the closest affinity with the extant Athrotaxis cupressoides. A detailed comparison of leaf morphology and the macro- and microstructure of the pollen and seed cones with related fossil species of Athrotaxis and Athrotaxis-like species reveals that the present fossil is a new species. Additionally, the occurrence of the fossil in the Zhonggou Formation and its similar characteristics with another fossil species, Athrotaxites berryi, suggests that Athrotaxites yumenensis sp. nov. might be an intermediate between Athrotaxites berryi and the extant Athrotaxis and that the new species is more closely aligned with extant Athrotaxis than with Athrotaxites berryi. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.

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.

Macrofossils of Carpinus have been widely reported from the Cenozoic of the Northern Hemisphere. However, the leaf cuticules of the genus have rarely been described. A new species, named Carpinus tengchongensis Dai et B.N. Sun, sp. nov., is identified based on 13 leaf fossils, collected from the late Pliocene Mangbang Formation, Tengchong County of Yunnan Province, China. The important characters of the fossil are its oblong-ovate leaf shape, obliquely cordate base, doubly serrulate margin, straight and moderately thick primary vein, pinnate secondary veins, percurrent tertiary veins, orthogonally reticulate areoles, absence of veinlets, anomocytic stomata with double-layered stomatal rim, well-formed T-pieces and trichome bases, which indicates an affinity within the genus Carpinus section Carpinus subsection Monbeigianae, especially with C. tsaiana. Carpinus fossils were present from the Eocene to Pliocene with disjunctive distribution in the North Temperate Zone, which broadly reflected the present distribution pattern and probably demonstrates the tolerance of Carpinus to environmental change.

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.

Well preserved late Pliocene-early Pleistocene megafossil leaves of Betula yunnanensis Zhi-Cheng Lin et Bai-Nian Sun sp. nov. were collected from the Mangbang Formation in southeastern Tengchong County, West Yunnan Province, China. Species determination was achieved by comparing the leaf architecture, cuticle and fine venation of the newly discovered specimens with thirty-four extant Betula species occurring in China and Japan, and four selected extinct species from China and Poland. Leaf architecture shows that the fossil species are most similar to the species of section Betulaster. Cuticular analysis of all the six species found in China and Japan belonging to section Betulaster (including Betula alnoides, B. rhombibracteata, B. cylindrostachya, B. luminifera, B. maximowicziana, B. fujianensis) was subsequently performed. Comparisons made between the extant and the extinct species confirm that based on leaf size, numbers of lateral vein and trichome types, B. yunnanensis is a new species. An explanation of why and how the peltate scales are only preserved as shield remains in the fossil materials is given. (C) 2010 Elsevier B.V. All rights reserved.

Although both fossil pollen and molecular data support a long evolutionary history for the Aquifoliaceae, reliable macrofossils have rarely been described. Here, a new species, Ilex protocornuta Xiang-Chuan Li et Bai-Nian Sun sp. nov. from the Late Miocene Xiananshan Formation of Zhejiang Province, East China, which is unequivocally identified based on eighteen leaf macrofossils, can be placed in the subgenus Ilex section Ilex subsection. The new species shows the closest affinity to Ilex cornuta Lindley et Paxton. A survey of Ilex fossil records (pollen and leaves) from the Cretaceous to the Pliocene in China suggests that the past distribution of fossil Ilex species is much wider than that of extant species, while the occurrence of the probably evergreen I. protocornuta may indicate that a warm and humid climate similar to that of today existed in East China during the Late Miocene, which is also supported by the co-occurring plants that prefer a tropical, subtropical or warm-temperate habitat (i.e. Smilax, Lagerstroemia and evergreen Quercus). (C) 2010 Elsevier B.V. All rights reserved.

Eight fossil leaves identified as Exbucklandia tengchongensis sp. nov. (Hamamelidaceae) were collected from the Pliocene Mangbang Formation in Tengchong, Yunnan Province, Southwest China. The fossil leaves are characterized by the overall rounded lamina with entire margin, actinodromous venation, and cyclocytic stomata, which suggest the affinity within the genus Exbucklandia , particularly with E. populnea . A survey on the cuticles of the sun and shade leaves of modern E. populnea indicates that the shade leaves generally possess more pronounced undulate anticlinal cell walls and a much lower stomatal density than the sun leaves. Two morphotypes, i.e. sun vs. shade types, of the fossil leaves were therefore recognized. The distribution of the modern Exbucklandia suggests that the genus lives under a warm climate with a mean annual temperature (MAT) from 13 °C to 27 °C and a mean annual precipitation (MAP) from 800 mm to 2500 mm. Hence, E. tengchongensis might also live under a similar climatic condition in the Pliocene. Leaf margin analysis on the Tengchong flora supports this result. The little change of Neogene MAT in Southwest China is therefore supported.