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1.
The high-mountain Chuya depression (Gorny Altai) was studied in 2006–2008. New data on the diversity of soil components of the soil cover in terms of the new Russian soil classification system have been obtained. Some relations of soil components to biotic and abiotic components of high-mountain steppe terrestrial ecosystems have been revealed.  相似文献   

2.
The ant fauna of the Chuya depression numbers 17 species, of which four species inhabit desert steppes, eight species occur in the near-water saline steppes, and eleven, in valley meadows and forests on mountain slopes. Of the 17 registered species, 14 are common in adjacent Mongolia and Tuva, which testifies to a high faunal commonness of these territories. The population pattern of ants is determined by two species with very low abundance (up to 0.01 nest/100 m2), Proformica mongolica Ruzsky and Cataglyphis aenescens Nylander, and in shallow hollows Formica subpilosa Ruzsky is added to them. Two zones with a higher density of population have been revealed in the vertical transzonal direction, in alpine desert steppes on the southern slopes (Yustyd River basin) and in the saline biotopes of the Chuya River floodplain.  相似文献   

3.
The middle-upper Eocene sequence at Gebel Na’alun, southeastern Fayum yielded 21 ostracod and four nummulite species. Out of these, two new ostracod species namely Bairdia crolifai and Paracypris naalunensis are described. Four ostracod assemblages are distinguishable; the lower three are assigned to the Bartonian and the upper one is Priabonian. The nummulites exist in three stratigraphic horizons represented from base to top by “Nummulites” aff. pulchellus, Nummulites decrouezae with Nummulites cavelieri (Bartonian) and Nummulites aff. fabianii (Priabonian).  相似文献   

4.
The main taxonomic and stratigraphical results of a study of ostracods from the middle-late Miocene of the Tremiti Islands and the Hyblean Plateau are presented. The faunas are mostly typical of deep thermospheric or psychrospheric bathyal environments. Excluding a few, mostly juvenile shallow water contaminants, a total of 127 species were recorded. Twenty-four taxa are discussed herein; of these, 13 species (Cytherella dissimilis nov. sp., Cytherella parvula nov. sp., Cytherella subtilis nov. sp., Argilloecia triangularis nov. sp., Retibythere (Retibythere)? claudii nov. sp., Retibythere (Retibythere)? gibba nov. sp., Cytheropteron (Cytheropteron) joachinoi nov. sp., Cytheropteron (Aversovalva) consuetum nov. sp., Cytheropteron (Aversovalva) trimerumense nov. sp., Cytheropteron (Aversovalva) turgidum nov. sp., Loxoconcha julianii nov. sp., Buntonia whatleyi nov. sp., Pterygocythere nuda nov. sp.) and a subspecies (Costa tricostata dorsoarcuata nov. subsp.) are described as new, while six are left in open nomenclature. The stratigraphical distribution of ostracods is expressed in terms of planktonic foraminiferal zones. Information obtained from this study enriches biostratigraphical data on Mediterranean Miocene deep-sea ostracods, especially with respect to the Langhian.  相似文献   

5.
亚洲新生代藓类植物化石非常稀少,漳浦琥珀是目前已知的我国低纬度地区唯一含苔藓植物化石的新生代琥珀矿床。漳浦琥珀源自中中新世气候适宜期(~14-17 Ma)的龙脑香树脂,温暖潮湿的热带季雨林气候和广泛分布的龙脑香科植物,为藓类植物的生长、多样性演化和三维立体保存提供了条件。本研究共报道了漳浦县中中新世藓类植物化石3个属种,包括:白发藓属Leucobryum Hampe、牛舌藓属Anomodon Hook.et Taylor和扁枝藓属Homalia(Brid.)B.S.G.。首次利用三维X射线断层扫描技术(Micro-CT)研究了白发藓属化石,发现其与现生种短枝白发藓Leucobryum humillimum Cardot非常相似,因此将其命名为短枝白发藓(相似种)Leucobryum cf.humillimum。此外,当前牛舌藓属Anomodon和扁枝藓属Homalia化石是东亚地区的首例记录。漳浦琥珀中的藓类植物化石揭示了中中新世时期苔藓植物的多样性,丰富了东亚低纬度地区新生代苔藓植物的化石记录。  相似文献   

6.
7.
Facies mapping of a late Miocene reef complex near the town of Níjar (Almería Province, southeastern Spain) demonstrated that Halimeda-rich beds compose about 20% of the proximal-slope sedimets. Halimeda segments are unbroken, preserved as molds, randomly oriented to layered, and concentrated in beds that commonly contain few fossils other than Halimeda. The associated biota (a laminar form of the coral Porites, articulated bivalves, small gastropods, and in-situ branching coralline algae) and sediment texture suggest possible insitu formation of the Halimeda.Repetitive stratigraphy characterizes the proximal reef-slope sediments at Níjar. Each repetition consists of the following idealized succession: an eroded base, mixed-fossil hash, Halimeda-rich beds, and mixed-fossil beds that contain little if any Halimeda. Although Halimeda beds do not dominate in the proximal-slope environment, their local abundance may signify changed environmental conditions.The concentration of Halimeda in beds suggests spatial segregation of Halimeda from many reef-dwelling organisms. The repetitive stratigraphy suggests temporal segregation as well.Episodic upwelling may have been responsible for the repetitive stratigraphy. The occurrence of Halimeda-rich beds in reef complexes of similar age throughout the Spanish Mediterranean region, and the occurrence of possibly correlative cyclic basinal sequences, is consistent with an upwelling mechanism. If responsive to upwelling episodes, Halimeda beds may represent event strata of regional significance.  相似文献   

8.
A newly discovered Konservat-Lagerstätte from the Middle Miocene of the western Olympus Range, Dry Valleys, Antarctica, yields cypridoidean ostracods complete with preserved body and appendages. This is the first record of three-dimensionally fossilized animal soft tissues from the continent. The ostracods are preserved in goethite, secondary after pyrite, representing a novel mode of exceptional preservation. They signal a high-latitude (greater than 77° south) lake setting (Palaeolake Boreas) viable for benthic animal colonization prior to 14 Myr ago. Their presence supports the notion of warmer, tundra-like environmental conditions persisting in the Dry Valleys until the Middle Miocene.  相似文献   

9.
《Palaeoworld》2021,30(4):757-769
Here we report a fossil flora from the Miocene Toupi Formation in Jiangxi Province, southeastern China, including megafossil genera Pinus, Podocarpus, Calocedrus, Cinnamomum, Quercus, Lithocarpus, Carya, Palaeocarya, Acer, and Yua. Among them, Yua jiangxiensis n. sp. is the first fossil record of the genus in Asia. A palynological analysis in this study reveals that the palyno-assemblage contains Selaginella, Pteris, Pinus, Picea, Quercus, Fagus, Carya, Ilex, and Rutaceae. Based on Integrated Plant Records (IPR) vegetation analysis, it is suggested that the fossil flora represents an evergreen broad-leaved forest, and the occurrence of tropical and subtropical Cinnamomum supports a warm and moist climate in the region during the middle Miocene.  相似文献   

10.
Abstract

Three species within the genus Calophyllum collected from middle Miocene Fotan Group sediments in Zhangpu County, Fujian, southeastern China are described in this paper. These fossils include Calophyllum zhangpuensis sp. nov., Calophyllum striatum, and Calophyllum suraikholaensis. The new fossil species C. zhangpuensis sp. nov. is oval, possesses entire leaves with closely spaced parallel secondary veins and has a round, or slightly retuse, apex. These specimens represent the first known fossil records of this relative wide leaf-type form of Calophyllum from China and have a length:width (L:W) ratio less than 3:1. In combination with the known modern geographic distribution and habitats of this wide leaf-type Calophyllum and other plants, data suggest that the middle Miocene Fotan flora is indicative of a warm climate. Thus, based on available fossil data, we speculate that this genus probably originated in India during the Paleocene before spreading from India to Bangladesh and into China, Sumatra, Malaysia, Indonesia, and Java during the Neogene, leading to its modern distribution. At least, the 3 fossil species in this region can explain floristic exchange between India, Fujian, and South China, which is consistent with previous studies; the occurrence of these 3 species indicates that Calophyllum began to diversity in China no later than the Miocene.  相似文献   

11.
The nine oceanic islands that comprise the Azores archipelago are located in the middle of the northern Atlantic Ocean. In this isolated archipelago, there is a rich fossil record in one of the islands, Santa Maria. In this island, samples were collected in the Upper Miocene composite section of Malbusca outcrop, located in the southern shore of the island, and the fossil marine Ostracoda were studied. This work represents the first report of fossil ostracods from the Azores archipelago. Thirteen species were found, representing seven families and 12 genera (Xestoleberis, Loxoconcha, Callistocythere, Leptocythere, Dameriacella, Aurila, Heliocythere, Pachycaudites, Neonesidea, Cyamocytheridea, ?Quadracythere and Paracypris). Among the identified species, one new species, Leptocythere azorica n. sp., is described. Loxoconcha (two species) was the most diversified genus. The collected species are mainly ornamented and typical of warm waters and epi-neritic habitats (~ 10–50 m of depth).  相似文献   

12.
Janz  Horst 《Hydrobiologia》2000,419(1):103-117
I present the findings of two detailed studies on Steinheim lake ostracods carried out over the last eight years. The 178 samples studied cover a combined section about 30 m thick, comprising the whole sequence of seven planorbid beds. Of the 53 species found, 44 occur in the basic sediment layers, the kleinibeds. In contrast, all of the subsequent beds contain 16 species, and only seven species withstood the extinction at the kleini–steinheimensis boundary.This may be mainly due to the loss of littoral habitats brought about by a constantly increasing lake level, as the majority of the species in the kleinibeds were shallow water dwellers. Long-term lake level fluctuations are considered the most important external factor of the post-kleini period. Density fluctuations of the ostracods Pseudocandona steinheimensis and Potamocypris gracilis broadly reflect these water level fluctuations. At the beginning of the sulcatusperiod, when the lake level was very high, some species show morphological changes in their carapaces. During this time Leucocythere immigrata split into the daughter species L. sieberi and L. esphigmena. In the following trochiformis period, when the water level was lowest, the most curious carapace sculptures appear. The morphological changes detected, however, cannot simply be interpreted as ecophenotypic. The speciation event in Leucocythere, the non-recolonization with ubiquitous species during the low water level stage (trochiformis period), as well as the types of morphological changes indicate mainly evolutionary processes, as also the planorbid molluscs prove. Moreover, ostracods and planorbids show convergent evolutionary patterns. Compared with data on ostracod speciation in ancient lakes, the ostracod assemblage of Lake Steinheim seems to be a good palaeontological example of intralacustrine evolution at an early stage.  相似文献   

13.
《Marine Micropaleontology》2001,41(3-4):109-123
Podocopine ostracods rapidly increased in species diversity after the Palaeozoic, and 32 out of the 36 podocopine families are extant (Whatley et al., 1993), but the phyletic origins are known for only a few. The Sigilliacea are unique in having a long and detailed fossil record. The Sigilliidae known from the recent and Mesozoic faunas differ from others ostracods in having large adductor muscle scars with many spots, a character typical rather to Palaeozoic forms. Paleozoic Microcheilinellidae were morphologically close to the sigilliids, but details of their hingement and carapace margin structures were unknown until now.Silicified specimens of Microcheilinella mendelgrammi, new species, from the Early Carboniferous of southern China and Microcheilinella mandelstami, from the Middle Devonian of north-western Poland show merodont hingement and narrow calcified inner lamella. This makes their relationship to the Mesozoic, Tertiary, and recent sigilliids Saipanetta, Cardobairdia, Sigillium, and Kasella likely. The sigilliid lineage was thus established already in the Devonian.Tubulibairdia, with adont hingement and tubulous shell wall, and Microcheilinella s. s., with merodont hingement and no tubules, are distinct genera in different families.  相似文献   

14.
Eight brachiopod species, i.e. Novocrania sp., Cryptopora lovisati (Dreger, 1911), “Terebratula” sp., Megathiris detruncata (Gmelin, 1791), Argyrotheca cuneata (Risso, 1826), Joania cordata (Risso, 1826), Megerlia truncata (Linnaeus, 1767), and Platidia anomioides (Scacchi and Philippi, 1844), have been identified in the Middle Miocene deposits of Kralice nad Oslavou, Moravia, Czech Republic. The species C. lovisati and P. anomioides dominate the studied assemblage, while others are very rare. Novocrania, C. lovisati and M. truncata are reported for the first time from the Moravian part of the Carpathian Foredeep. In species composition, the assemblage from Kralice resembles other Middle Miocene Paratehyan assemblages, interpreted as shallow water, but the dominance of C. lovisati and P. anomioides makes it clearly different, indicating an environment deeper than 100 m.  相似文献   

15.
16.
Foraminiferal and ostracod assemblages from two upper Oligocene to lower Miocene sections located in the Wetterau region (NE Frankfurt a. M.) were analysed. The lithologie units investigated encompass Cyrenenmergel, Glimmersand, Vilbeler Kies, Cerithiensand, Cerithienkalk andCorbicula-Schichten. Hemicyprideis basiliensis, H. helvetica andCypridopsis? cyclocypriformae are characteristic of Cyrenenmergel deposits, representing the last marine influence around the Rupelian/Chattian boundary. The ostracod assemblages from the Cerithiensand are characterized by variousHemicyprideis species, of whichH. rhenana is the most frequent. The microfossil assemblages of the Cerithiensand indicate normal marine conditions for the basal and upper portions of the unit and slightly brackish to normal marine conditions for the middle portion. Very low salinities are indicated for some levels close to the base (around levels of emergence above sealevel) and for the clay layer around sample 30 in the lower part of the Cerithiensand. The Cerithienkalk represents a transitional facies from normal marine to brackish/freshwater conditions as indicated by successive higher contents of stress tolerant foraminifera and freshwater ostracods. TheCorbicula-Schichten are characterized by largeEucypris-moulds and various proportions ofCypridopsis spp. (freshwater indicators). When foraminifera (Bolivina spp.) are present, the fauna indicates slightly higher but still low salinities for a few levels of theCorbicula-Schichten. Oxygenation levels were generally high (presence of large ostracods and epifaunal foraminifera) and vary from suboxic to high oxic. As in the Mainz Basin, the last occurrence ofHemicyprideis rhenana marks the upper boundary of the Cerithienschichten.Protelphidium nonioninoides can be used to identify the Cyrenenmergel when it occurs in high numbers. Cerithiensand-samples show the highest diversities and contain high portions ofUvigerinella michelsi. Overall, highest diversities and normal marine salinities are reached during deposition of the basal and upper parts of the Cerithiensand, which may correspond to global sealevel rises at the end of the Chattian.  相似文献   

17.
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.  相似文献   

18.
Ostracod faunas at six locations are compared, and related to distributions in an Atlantic Ocean-wide data base. Five, widely developed, vertical faunal sequences are recognised at particular levels within deep water-masses: Henryhowella Fauna (lower part of Antarctic Intermediate Water); Krithe Fauna (Upper North Atlantic Deep Water); Poseidonamicus-Bosquetina Fauna (upper part of Lower NADW); Dutoitella Fauna (lower part of Lower NADW); Legitimocythere Fauna (Antarctic Bottom Water). These faunas are correlated with previously established deep water benthic foraminiferal assemblages, and their possible palaeo-oceanographic use is discussed.  相似文献   

19.
20.
A review of the freshwater ostracods of New Zealand   总被引:1,自引:1,他引:0  
Summary The freshwater ostracod fauna of New Zealand is reviewed, and a key is given to the 28 known living species, belonging to 18 genera. 10 new species are described, and 8 genera are recorded for the first time from New Zealand. Brief notes on the habitat and life-history of some of the species are given.Present address: Dept. of Zoology, The University, Glasgow  相似文献   

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