兰州盆地早第三纪植物及古气候意义

化石采自甘肃省兰州盆地咸水河组底部,经研究认为有29种,归属20属12科。它们是：樟科 Lauraceae (Daphnogene),木通科Lardizabalaceae(Akebia),小檗科Berberidaceae(Berberis),榆科Ulmaceae (Planera,Ulmus,Zelkova),桦木科Betulaceae(Alnus,Carpinus),杨梅科Myricaceae(Myrica),杨柳科Sali- caceae(Populus,Salix),紫金牛科Myrsinacese(Ardisia),蔷薇科Rosaceae (Prunus,Sorbus,Sorbaria,Spir- aea),豆科Leguminosae(Gleditsia,Sophora),漆树科 Anacardiaceae(Rhus),忍冬科Caprifoliaceae(Viburnum) 等。经植物区系组成与叶相分析显示,该植物区系的大多数成员是落叶阔叶乔、灌木,少数为常绿灌木。其中特殊的分子是 Rhus turcomanica Korov．ex Vassilvesk,该成分是早第三纪中、晚期的标志化石植物。另一化石植物 Sorbaria callicomifolia Kornilova曾出现在中亚的早渐新世,最晚至早中新世。同一层位采集的孢粉样分析结果显示：该组合仅约20种,种类相对贫乏,并以被子植物的花粉占优势。其中出现裸子植物的麻黄粉,被子植物的白刺粉及蒿粉等,这几个类型均指示沉积时期经历干旱气候。综合植物大化石及孢粉分析研究,均出现一些指示气候为亚热带干旱或周期性干旱气候的特点,并据Rhus turcomanica出现的最晚记录,推测咸水河组底部的地质时代大约是早渐新世晚期。     

History of the development of the temperate forest flora in Kazakhstan,U.S.S.R. from the Oligocene to the Early Miocene

Exact dating of the floras existing in western Kazakhstan during the Oligocene and Early Miocene permits a detailed examination of the formation of a temperate flora during the Rupelian (Early Oligocene), Chattian (Late Oligocene), Aquitanian (the beginning of Early Miocene) and the Burdigalian (end of Early Miocene) Ages and at the same time an establishment of the sequence in the origin and the disappearance of a flora of Turgayan type (the “Turgayan flora” of Kryshtofovich) in Kazakhstan. The most important aspects (composition and terminology) of a previous subtropical flora of a Drevlyanian (possibly Volynian) ecological type (the “Poltavian” flora of Kryshtofovich), which had developed in Kazakhstan and the Ukraine during the Eocene, are also discussed. The text is intended for botanists of various special interests, e.g., paleobotanists, phytogeographers and floristicians, as well as for geologists, especially stratigraphers and paleogeographers. The bibliography comprises more than 200 references and there are seven tables.     

Biogeography of cedrela (meliaceae, sapindales) in central and South america

Dated phylogenies have helped clarify the complex history of many plant families that today are restricted to the world's tropical forests, but that have Eocene, Oligocene, and Miocene fossils from the northern hemisphere. One such family is the Meliaceae. Here we infer the history of the neotropical Meliaceae genus Cedrela (17 species), the sister clade of which today is restricted to tropical Asia. Sequences from the nuclear ribosomal spacer region and five plastid loci obtained for all ingroup species and relevant outgroups were used to infer species relationships and for molecular-clock dating under two Bayesian relaxed clock models. The clock models differed in their handling of rate autocorrelation and sets of fossil constraints. Results suggest that (1) crown group diversification in Cedrela started in the Oligocene/Early Miocene and intensified in the Late Miocene and Early Pliocene, and (2) Central American Cedrela species do not form a clade, implying reentry into Central America after the closure of the Panamanian Isthmus. At present, Cedrela is distributed in both dry and humid habitats, but morphological features suggest an origin in dry forest under seasonal climates, fitting with Miocene and Pliocene Cedrela fossils from deciduous forests.     

Major vegetation trends in the Tertiary of Patagonia (Argentina): A qualitative paleoclimatic approach based on palynological evidence

The patterns of Patagonian vegetation change suggest a strong relationship between the major thermal characters of the flora and the global paleoclimatic trends during Tertiary times. This conclusion was reached from the assessment of fossil pollen data from Patagonia throughout the Paleogene and Early Neogene periods and the subsequent comparison of palynological data to the global deep-sea oxygen isotope record. Four main time intervals were recognized based on the temporal distribution of selected angiosperm key taxa. (1) Paleocene to Early Eocene: presence of megatherm elements (e.g. Nypa, Pandanus), probably integrating mangrove communities in Patagonian lowlands. (2) Middle Eocene to Early Oligocene: rise to dominance of mesotherm and microtherm Nothofagus species. Megatherm taxa were well recorded at the beginning of this interval (e.g. Ilex) but were shown to disappear towards the end. (3) Late Oligocene to Middle Miocene: new increases of megatherm taxa such as palms, Cupania and Alchornea. First occurrences of mesotherm Asteraceae, represented by trailing Mutisieae, were reported. (4) Late Miocene: dispersal of meso-microtherm and arid adapted taxa (e.g. Ephedraceae and Asteraceae) across the non-Andean region of Patagonia. Microtherm Nothofagacean forests probably occurred on the higher rainfall regions of western Patagonia. The current vegetation was most likely reached during this last stage with the forest development under wetter conditions on the Andean sectors, and the steppe throughout the non-Andean region of Patagonia.     

Palaeogene palaeobiogeography of the Indian subcontinent

Certain palaeoecological criteria in the reconstruction of the Palaeogene palaeobiogeography of the Indian subcontinent are discussed. The Early Palaeogene is characterised by marine oscillations, a prolific invertebrate fauna, extensive coal facies development and outpouring of basaltic lava flows, the last being a feature connected with the movement of the Indian Plate and coinciding with a Himalayan orogenic impulse. The Middle Eocene transgression marks the transition of marine sedimentation to fluvial conditions in northern India with the presence of a fairly diverse mammalian fauna in northwestern Pakistan and northern India. During the Late Oligocene, mammals clearly ancestral to the much more prolific Siwalik fauna were present in western Pakistan, northeastern India and southcentral Burma.The flora consists of mainly tropical to subtropical families with the addition of some temperate elements in Assam in the latter half of the Eocene and Oligocene. Invertebrates indicate a close affinity between the western and eastern sectors and suggest that the sea was continuous in the north at least up to the Palaeocene. With the emergence of land in the northeastern part of the subcontinent, the fauna of Assam acquired distinct Indo-Pacific elements similar to those of Burma and the Indonesian Arc. Later, the sea was divided into two gulfs which gradually shrank towards the end of the Palaeogene and disappeared by the Middle Miocene.     

New fossil leaves and fruits of Lauraceae from the Middle Miocene of Fujian,southeastern China differentiated using a cluster analysis

The fossil record of Lauraceae can be traced back to the Early Cretaceous of eastern Asia based on fossil flowers. Here, we refer a number of new occurrences of leaf and fruit fossils of Lauraceae from the Middle Miocene of Zhangpu, Fujian, China, to seven species. These data provide evidence supporting the fact that a diverse subtropical, or tropical, Lauraceae-dominated evergreen forest surrounded this region 15 million years ago (Mya). The Lauraceae fossils presented in this paper provide evidence for the evolution of this group as well as new materials that enable the study of the Fujian Province Neogene flora. The fossils described in this paper fill in the gaps in studies about Lauraceae pollen in the Middle Miocene from Fotan, Fujian, China. In addition, these fossils also enrich the Middle Miocene fossil records of Lauraceae in eastern Asia, especially improving the study of the macrostructures and reproductive organs of fossil Lauraceae from southern China. The similarity between fossil and modern fruits shows that during the Middle Miocene the fruit morphological of Lauraceae have changed very little. We also identify families where the fossils we report belong to their closest relatives and can be used to reconstruct the paleoenvironment of Fujian in the Middle Miocene.     

Climatic niche evolution in Smilacaceae (Liliales) drives patterns of species diversification and richness between the Old and New World

Geographical variation in species richness in plant groups is determined by the interplay between historical, evolutionary, and ecological processes. However, the processes underlying the striking disparity in species richness between Asia and the Americas remain poorly understood. Here, we synthesize global phylogenetic and macroecological data on the diversification of Smilacaceae, deciphering potential drivers underlying the species diversity pattern biased toward Asia. We compiled global distributions of all Smilacaceae species, and reconstructed the biogeographic history and niche evolution using a new time-calibrated phylogeny (eight genes, 135 species). Integrating these data sets, we estimated evolutionary histories and diversification rates for each region, and tested correlations among species diversification, niche evolution, and niche divergence. Smilacaceae probably originated during the Late Cretaceous/Early Palaeocene and began to diversify in middle to low latitudes in Central America and Eurasia during the Late Eocene. Both the Old and New World clades exhibited a steady, albeit slight, increase of species diversification from the Late Eocene to Early Miocene. However, the Old World clade experienced an abrupt increase in net diversification during the Late Miocene. Our findings also revealed that species diversification rates were positively correlated with ecological niche evolution and niche divergence. Niche shifts and climatic niche evolution since the Middle Miocene played crucial roles in species diversification dynamics within Smilacaceae. The high plant richness in Asia may be explained by greater diversification in this region, potentially promoted by heterogeneous environments.     

Evolution of bird communities in the Neogene of Central Asia,with a review of the Neogene fossil record of Asian birds

A complete taxonomic review of Neogene birds of continental Asia is provided. To date, avifauna from the latter half of the Miocene and Pliocene of Central Asia (Mongolia and adjacent regions of Inner Asia) are most thoroughly investigated. Available data enable a reconstruction of successive replacement of Early and Middle Miocene avifaunas by communities of the Recent type. Middle Miocene avifaunas of Mongolia include a great number of extinct genera and species, many of which were widespread in Eurasia. Extant genera became dominant in the Late Miocene and taxa close to living species appear in the Late Pliocene fossil record. Late Pliocene communities of birds of Central Asia were complex in genesis, composed of Miocene relicts (Struthio), immigrants from the European regions of the Palearctic (phasianid Plioperdix), North American immigrants (Calcarius), and also autochthonous elements, the origin of which is apparently connected with the arid belt of Central Asia (diverse passerines).     

Divergence time estimation in Cichorieae (Asteraceae) using a fossil-calibrated relaxed molecular clock

Knowing the age of lineages is key to understanding their biogeographic history. We aimed to provide the best estimate of the age of Cichorieae and its subtribes based on available fossil evidence and DNA sequences and to interpret their biogeography in the light of Earth history. With more than 1,550 species, the chicory tribe (Cichorieae, Asteraceae) is distributed predominantly in the northern Hemisphere, with centres of distribution in the Mediterranean region, central Asia, and SW North America. Recently, a new phylogenetic hypothesis of Cichorieae based on ITS sequences has been established, shedding new light on phylogenetic relationships within the tribe, which had not been detected so far. Cichorieae possess echinolophate pollen grains, on the surface of which cavities (lacunae) are separated by ridges. These lacunae and ridges show patterns characteristic of certain groups within Cichorieae. Among the fossil record of echinolophate pollen, the Cichorium intybus-type is the most frequent and also the oldest type (22 to 28.4 million years old). By using an uncorrelated relaxed molecular clock approach, the Cichorieae phylogenetic tree was calibrated with this fossil find. According to the analysis, the tribe originated no later than Oligocene. The species-rich core group originated no later than Late Oligocene or Early Miocene and its subtribes diversified no later than Middle/Late Miocene or Early Pliocene—an eventful period of changing geological setting and climate in the Mediterranean region and Eurasia. The first dispersal from Eurasia to North America, which resulted in the radiation of genera and species in North America (subtribe Microseridinae), also occurred no later than Middle or Late Miocene, suggesting the Bering land bridge as the route of dispersal.     

Middle Eocene–Early Pliocene Subantarctic planktic foraminiferal biostratigraphy of Site 1090, Agulhas Ridge

The analysis of planktic foraminiferal assemblages from Site 1090 (ODP Leg 177), located in the central part of the Subantarctic Zone south of South Africa, provided a geochronology of a 330-m-thick sequence spanning the Middle Eocene to Early Pliocene. A sequence of discrete bioevents enables the calibration of the Antarctic Paleogene (AP) Zonation with lower latitude biozonal schemes for the Middle–Late Eocene interval. In spite of the poor recovery of planktic foraminiferal assemblages, a correlation with the lower latitude standard planktic foraminiferal zonations has been attempted for the whole surveyed interval. Identified bioevents have been tentatively calibrated to the geomagnetic polarity time scale following the biochronology of Berggren et al. (1995). Besides planktic foraminiferal bioevents, the disappearance of the benthic foraminifera Nuttallides truempyi has been used to approximate the Middle/Late Eocene boundary. A hiatus of at least 11.7 Myr occurs between 78 and 71 m composite depth extending from the Early Miocene to the latest Miocene–Early Pliocene. Middle Eocene assemblages exhibit a temperate affinity, while the loss of several planktic foraminiferal species by late Middle to early Late Eocene time reflects cooling. During the Late Eocene–Oligocene intense dissolution caused impoverishment of planktic foraminiferal assemblages possibly following the emplacement of cold, corrosive bottom waters. Two warming peaks are, however, observed: the late Middle Eocene is marked by the invasion of the warmer water Acarinina spinuloinflata and Hantkenina alabamensis at 40.5 Ma, while the middle Late Eocene experienced the immigration of some globigerinathekids including Globigerinatheka luterbacheri and Globigerinatheka cf. semiinvoluta at 34.3 Ma. A more continuous record is observed for the Early Miocene and the Late Miocene–Early Pliocene where planktic foraminiferal assemblages show a distinct affinity with southern mid- to high-latitude faunas.     

British mammals in the Tertiary period

British Tertiary mammals are best represented in the Eocene and earliest Oligocene epochs. Additional occurrences are from the Miocene and Late Pliocene. The Eocene is marked by the occurrence of various extinct orders as well as the appearances of some of the earliest and must primitive artiodactyls and perissodactyls. The appearances in the Early Eocene and Early Oligocene represent major dispersal events, reflecting penecontemporaneous palaeogeographic changes. In the intervening timespan Britain was part of an European island, sharing its endemic terrestrial fauna. From the late Middle Eocene to earliest Oligocene, the British record is detailed enough to trace successive changes in the patterns of diversity and faunal turnover, which may relate to changing climate as well as to the dispersal events. It has been shown that changes in patterns of ecological diversity through the Eocene and earliest Oligocene match vegetational changes judged from plant fossils. They suggest a gradual transition from closed forest in the Early Eocene to a more open environment with reedmarsh and wooded patches by the end of the epoch.     

Early Miocene repetitive vegetation and climatic changes in the lacustrine deposits of the Rubielos de Mora Basin (Teruel, NE Spain)

Pollen analysis of a Lower Miocene succession from the Rubielos de Mora Basin (NE Spain) has been carried out with the aim of reconstructing the flora, vegetation and climatic changes. Previous paleobotanical studies on these sedimentary rocks and adjacent areas interpreted very diverse climates for the Early Miocene: from humid temperate to dry subtropical. In this study, a rich thermophilous pollen spectrum and a diverse subarid flora including Nitraria, Caesalpiniaceae, Ephedra and Acacia, indicative of a dry subtropical climate are identified. On the other hand, mesothermic taxa with high water requirements are also abundant. Therefore, the pollen assemblages evidence the juxtaposition of very contrasted environments: the presence of subdesertic taxa, typical of plants growing in the lowlands and conditioned by a long warm, dry season, together with others with very high water requirements, needing constant water. This can be explained by the presence of the Rubielos de Mora Lake providing local conditions for developing riparian forests. The vegetation was clearly controlled by the water availability under a subtropical and dry-seasonal climate. Pollen changes along the succession, which coincide with sedimentological changes, are related to climatic variations. Alternation in pollen taxa (thermophilous–dry vs. mesothermic–riparian) reflects the influence of the cyclicity of temperature and precipitation on the lake level and vegetation.     

北部湾盆地海中凹陷古近纪古气候研究

古气候对烃源岩的发育具有重要的控制作用,温暖湿润的气候成为优质湖相烃源岩发育的有利气候条件。本次根据X1井及X2井的孢粉资料及粘土矿物数据,采用孢粉定量统计分析与粘土矿物分析相结合的方法,对海中凹陷中始新世—晚渐新世的古气候进行了研究。研究显示海中凹陷流沙港组二段沉积时期(中—晚始新世)气候相对温暖湿润,为南亚热带湿润—半湿润气候;流沙港组一段沉积时期(晚始新世—早渐新世早期)气候开始转凉,为中亚热带湿润—半湿润气候;涠洲组沉积时期(早渐新世晚期—晚渐新世晚期)气候逐渐变得干燥,为中亚热带半湿润—半干旱气候,同时明确了流沙港组二段沉积时期为海中凹陷优质湖相烃源岩发育的最佳时期。     

试论晚白垩世以来气候、地理等因素的变化对鼍类的进化及地理分布等影响

现存的鼍属只有两个种:即东亚的扬子鳄及北美的密河鳄。虽然这两个种的性质、纬度分布以及生态环境等都十分相似;但两者的水平分布的距离却几有地球的半圈。本文根据有关鼍类的进化、迁徙等的历史资料,对此进行了初步的探讨。     

俄罗斯阿穆尔河东部上泽亚坳陷始新统孢粉

报道一个产于上泽亚(Uupper Zeya)坳陷(东经129-130°,北纬54-55°)东南部,保存良好的化石孢粉植物群.孢粉组合中裸子植物花粉居统治地位,占总数的53.4%,其中Taxodiaceae占36.3%,松科仅占5%.被子植物花粉占39.9%,多为葇荑花序类,如胡桃科、桦木科、山毛榉科等;同时还有不少反映温暖气候的分子,如Liquidambar,Balsaminaceae,Magnoliaceae,Nyssaceae等.孢子植物占21%.这样的孢粉植物群代表了潮湿温暖的温带气候.孢粉学至今在坳陷区内仍是人们用以确定地层时代的唯一依据.Pistillipollenites macgregorii,Anacolosiditessuplingensis,Ulmoideipites tricostatus及U. crempii等的出现可以确定含孢粉地层的地质时代属于中-晚始新世.斯涅日诺戈斯克产煤区中晚始新世沉积中的孢粉层位与普里阿姆尔耶,雅库提亚和亚洲东北部的同期沉积相当.     

西藏新生代秋乌组孢粉化石的发现及其初步研究

本文首次报道西藏雅鲁藏布江缝合带附近秋乌组含煤沉积中的孢粉化石。孢粉植物群主要由Quercoidifes,具孔类及三孔沟类花粉组成,包括12科26属及一些未定类群。组合中产有少量的Graminidites及Tsugaepollenites。植物群的总体特征显示其时代可能为渐新世至早中新世。秋乌组沉积早期的环境比较温暖。     

Lizards of the family Arretosauridae Gilmore, 1943 (Iguanomorpha, Iguania) from the Paleogene of Mongolia

The family Arretosauridae is an enigmatic group of Asian iguanians, which contains one species, Arretosaurus ornatus Gilmore, 1943 from the Late Eocene of Inner Mongolia (China). In this work, the fossil family is classified within the taxon Iguanomorpha (Iguanidae sensu lato) and supplemented with three new forms from the Middle Eocene and Early Oligocene of Mongolia and the previously described Hemishinisaurus latifrons from the Late Eocene of China, which was originally assigned to Anguimorpha (Xenosauridae). New data characterize Arretosauridae as an important element of the Paleogene herpetofauna of Asia.     

Bombacaceae pollen from the Indian Tertiary sediments and its bearing on evolution and migration

Several pollen species recovered from the Indian Tertiary sediments have close similarities with pollen of extant Bombacaceae. These morpho species are included in the morphogenera Lakiapollis Venkatachala and Kar, Dermatobrevicolporites Kar, Bombacacidites Couper, Tricolporocolumellites Kar and Retitribrevicolporites Kar. Nine species are re-described on the basis of original type material or other specimens. The fossil pollen belongs to the Bombax- and Durio-types. The small-sized Bombax-type pollen (e.g., Eriotheca pollen) has been documented in India from the early Palaeocene to the Miocene while large-sized pollen similar to that of Bombax appeared in the Oligocene and continued up to the Present. The lobed variety of the Bombax-type is rare and occurs only in the Pleistocene. Palynological evidence suggests a migration of Bombacaceae producing Bombax-type pollen to India from Africa. Durio-type pollen appeared in the late Palaeocene and continued to dominate until the early Eocene. In southern India, this pollen remained frequent during Oligocene/Miocene times, whereas in other areas, it became rare at the end of the Eocene. The earliest (late Palaeocene) record suggests an origination of Bombacaceae producing Durio-type pollen in India and a subsequent migration to Southeast Asia.     

内蒙千里山地区中、上渐新统的发现及其意义

在这篇文章中,根据所发现的脊椎动物化石和岩性,将内蒙伊克昭盟千里山地区陆相第三纪地层分为四部分。并建立了两个组:上部上渐新统伊克布拉格组和中部中渐新统乌兰布拉格组。后者被分为上、下两段。在亚洲,一直未能发现完整的,具有丰富脊椎动物化石的中、晚渐新世地层的剖面。千里山地区渐新统连续剖面的发现,对亚洲中、晚渐新世地层的层序的建立和对比提供了可靠的依据。     

First macrofossil record of Icacinaceae in East Asia (early Oligocene,Wenshan Basin) and its ecological implications

Icacinaceae are well represented in the modern tropical flora of East Asia, but this family has no confirmed macrofossils from this region. Most of the unambiguous fossils (e.g., endocarps) are from the Paleogene of North America and Europe, where the family is no longer present. Here we report a fossil endocarp of the liana genus Iodes from the Oligocene Wenshan flora, southwestern China. The fossil is relatively large (ca. 20 mm length, 11 mm width) and documents a vascular bundle inside the endocarp wall, a pattern of ridges enclosing few areoles, and an asymmetrical apex and rounded base. On the basis of these characteristics, we described a new species, Iodes elliptica, which represents the first Icacinaceae fruit fossil record from Asia. This fossil, consistent with recent reports of Iodes pollen from the Eocene of Hainan, indicates a long-standing presence of the genus in SE Asia, dating back to the Paleogene. Based on the climatic data of modern Iodes, and other fossil occurrences from Wenshan, we hypothesize that the climate in the region was subtropical during the Oligocene, supporting a rainforest, with an overall mixed regional flora of subtropical and tropical elements.