美科学家在地球最深海沟发现有孔虫类巨大变形虫

据2011年10月25日《科技日报》援引美国物理学家组织网2011年10月23日报道，2011年7月，美国加利福尼亚大学圣地亚哥分校斯柯里普斯研究人员和国家地理工程师航行到太平洋玛丽亚娜海沟，到达目前已知的地球最深海域，在那里的塞利娜深海区水下10541m的地方探测到了一种名为Xenophyophores的单细胞有孔虫类变形虫。它们一般都超过lOom，且数量极大，在各种生物中明显居于主导地位。研究人员介绍，这种变形虫是现存最大的单细胞动物，是一种很适于黑暗、低温和深海高压环境的生命形式，能通过捕获水中粒子积聚高浓度的铅、铀和汞，还能抵抗高剂量的重金属。

山东半岛南部近岸海域晚第四纪以来有孔虫和介形类化石群落分布特征及古环境演化

在山东半岛南部近岸海域QDZ03孔16．2m的沉积记录中，通过有孔虫和介形类化石群落的定量分析，探讨了研究区晚第四纪氧同位素（MIS）4期以来古沉积环境演变。在距今6万年前后开始的黄海海退期（相当于MIS4期），发育了有多次沉积间断的第1层（孔深16．2～12．0m）陆相地层。进入玉木亚间冰期（相当于MIS3）后，由于海平面的震荡上升，发育了第2层-第5层的滨岸弱海相一陆相沉积层，其中第5层上部可能包含部分MIS2期的产物，而MIS2期绝大部分沉积地层缺失。在距今12000ll000年前，海水逐渐由黄海入侵到青岛地区，发育了第6层下段（孔深9．1—8．6m）的海陆过渡相沉积层；在全新世最大洪泛面MFS来临之前（距今约11．0-9．0ka期间），海平面进一步上升，钻孔中发育了第6层中段（孔深8．6—7．7m）的滨岸相沉积层。随着距今6000年前南黄海最大海泛面出现，后降至现今水平，并基本保持稳定状态，在黄河、近岸短源河流以及海岸带基岩侵蚀物等物质联合贡献下完成了南黄海中部泥质沉积体在近岸的延伸（7．7m以上），其中顶部约4．8m以上粒度粗化及与之相关的较多含量胶结壳有孔虫化石的出现，可能与约3000～2000年以来海岸带地区人类活动的加剧有关。

Biostratigraphy of a Paleocene-Eocene Foreland Basin boundary in southern Tibet

This study of the Paleocene—Eocene boundary within a foreland basin of southern Tibet, which was dominated by a carbonate ramp depositional environment,documents more complex environmental conditions than can be derived from studies of the deep oceanic environment.Extinction rates for larger foraminiferal species in the Zongpu-1 Section apply to up to 46%of the larger foraminiferal taxa. The extinction rate in southern Tibet is similar to rates elsewhere in the world,but it shows that the Paleocene fauna disappeared stepwise through the Late Paleocene,with Eocene taxa appearing abruptly above the boundary.A foraminifera turnover was identified between Members 3 and 4 of the Zongpu Formation—from the Miscellanea—Daviesina assemblage to an Orbitolites—Alveolina assemblage.The Paleocene and Eocene boundary is between the SBZ 4 and SBZ 5,where it is marked by the extinction of Miscellanea miscella and the first appearance of Alveolina ellipsodalis and a large number of Orbitolites. Chemostratigraphically,theδ^(13)C values from both the Zongpu-1 and Zongpu-2 Sections show three negative excursions in the transitional strata,one in Late Paleocene,one at the boundary,and one in the early Eocene.The second negative excursion ofδ^(13),which is located at the P—E boundary,coincides with larger foraminifera overturn.These faunal changes and the observedδ^(13)C negative excursions provide new evidence on environmental changes across the Paleocene—Eocene boundary in Tibet.

Modern planktonic foraminifera from the eastern Indian Ocean

A brief morphometric study of the recent planktonic foraminifera in the eastern Indian Ocean was provided with the taxonomic key to species,synonyms,SEM microphotographs of shells and chamber arrays.By recent classification,currently 20 species representing 13 genera and 6 families(Canderinidae,Heterohelicoidae,Hedbergellidae,Higerigerinoidae,Globigerinoidae,and Globorotaloidae)identified from the planktonic material of the eastern Indian Ocean up to a depth of 200 m.Their distribution in water(0–200 m)also reports on the new range of expansion in the eastern Indian Ocean,with Dentigloborotalia anfracta,Hastigerina pelagica,Streptochilus globigerus,Globigerinella calida,Globigerinella adamsi,Orcadia reidelii,Tenuitella parkerae,Tenuitella compressa,reported for the first time in this study area.In general,only around 50 planktonic species are valid worldwide,more specifically the species,e.g.,H.pelagica,G.calida,G.adamsi,S.globigerus,O.riedeli,T.parkerae,T.compressa,which occur in the eastern Indian Ocean to fill the the paucity of the recent regional taxonomic literature and the problematic identification from the eastern Indian Ocean.This work aims to bridge this gap and help scientists,managers,educators and students to identify plankton foraminifers by using species notes and images.

Variation on Foraminiferal Composition in Cretaceous Black-Gray-Red Bed Sequence of Southern Tibet, China

An Upper Cretaceous black-gray-red bed sequence was deposited in the Tethys-Himalayan Sea where abundant foraminifera,especially planktons,were yielded. In the shallow shelf to the upper slope on the north margin of Indian plate was recorded an extinction-recovery-radiation cycle of foraminiferal fauna highly sensitive to paleoceanographical changes. The black unit, consisting of the Late Cenomanian-earliest Turonian beds, displays a major extinction, with keeled planktonic and many benthic species as the principal victims at the end of the Cenomanian when existed only low diversity, surface water-dwelling foraminifera. The gray unit spans a long-term recovery interval from the Turonian to the early Santonian with keeled planktonic foraminifera returning stepwise to the water column. The planktonic biota in the red unit, extremely abundant, indicate a biotic radiation during the Late Santonian and the Early Campanian, implying that the high oxygen levels had returned to all the oceanic depth levels, and that the water stratification disappeared, followed by the radiation of all depth-dwellers. The variation on foraminiferal faunas from the whole sequence refers to the extreme warm climate that appeared in the Middle Cretaceous and to the declined temperature toward the late epoch. Substantial deposits for this warming and cooling zones represent the black shales in the Middle Cretaceous and the red beds in the later period of the southern Tibet. The change in the foraminiferal composition corresponded to the formation of dysaerobic facies and to the development of high-oxidized circumstances.

Morphology of four Miliolinella species (Foraminifera, Protozoa) with description of a new species, Miliolinella obesa nov. spec., from the tropical West Pacific Ocean

Foraminiferal oozes were sampled from the tropical West Pacific seamount and seabed of deep sea,by a remotely operated vehicle(ROV)in December 2014 and March 2016.Using standard morphological method,four Miliolinella species,including Miliolinella obesa,M.circularis,M.suborbicularis and M.subrotunda were described.Among the four species,M.obesa is a new species.It is a large member(about 500μm in length)of the genus.This species is characterized by having a very stout and transverse broadly circular outline,and its body width is greater than the body length.In addition,its chamber demarcations are obscure from the exterior appearance.Three chambers are unclearly visible on one side and two chambers are visible on the opposite.Finally,we provided very detailed taxonomic microphotographs and the ecological distribution information for each species.

Paleoenvironmental implications of the calcium isotope characteristics in the MD81349 from the Nintyeast Ridge in the Indian Ocean

A δ^(44) Ca curve from shells of the planktonic foraminifera Globigerinoides sacculifer in calcareous biogenic oozes has been extracted from the Nintyeast Ridge in the Indian Ocean since 300 ka. By combining terrigenous inputs(e.g., grain size, magnetic susceptibility, and turbidite frequency) with the oceanic productivity(e.g., biogenic content and Neogloboquadrina dutertrei content), it is found that the curve's variations are closely related to the historical evolution of the oceanic calcium cycle. The δ^(44)Ca value is in lower tendency and has small oscillation during Marine Isotope Stage(MIS) 6, when the supply of terrigenous detrital is highest. In contrast, during MIS 3,5 and 7, the δ^(44) Ca values are in higher tendency, and their fluctuations are consistent with the variations of the productivity proxies. These results suggest that the calcium isotopes are mainly influenced by the input of the Himalayan erosion products to the northern Indian Ocean. In addition, the developmental stages of calcareous planktons may have a secondary impact on the fluctuations of the calcium isotope ratio of sea water.

Foraminifera in Cenozoic Paleoenvironments

Paleontologists search the fossil record for evidence of age, ancient environments, phylogenetic reconstructions and ancient communities. Cenozoic foraminifera preserve evidence for all of these simultaneously from the water column and from at, above and below the sediment/water interface. As our understanding of foraminiferal assemblages and their place in the strata (biofacies) becomes more sophisticated, so are foraminiferal biofacies challenged to contribute to more subtle problems in Cenozoic earth and life history. Progress is described as a series of five “integrations”. (Ⅰ) The quantification of foraminiferal biofacies was an advance on simple presences and absences of species meeting such questions as marine or nonmarine, or shallow or deep. (Ⅱ) Foraminiferal shells carry geochemical signals especially isotopes of oxygen (temperature, ice volume), carbon (nutrition and the carbon cycle), and strontium (seawater ratios through time). (Ⅲ) From modern foraminiferal biology we have lifestyle insights leading to a model of oceans and paleo-oceans called the trophic resource continuum, a valuable way into greenhouse-icehouse comparisons and contrasts. (Ⅳ) Biofacies changes in space and time are sometimes abrupt with little evidence of diachrony, and sometimes gradual. These patterns are clarified in the context of sequence stratigraphy (which they enrich in turn). (Ⅴ) The paleobiological counterpart of sequence stratigraphy is evolutionary paleoecology, reconstructing communities in deep time. The foraminifera are perfectly suited to investigate the possibility (or likelihood) that global environmental shifts have controlled community turnover in the pelagic, neritic and terrestrial realms.

湖南慈利康家坪剖面二叠纪末类有孔虫的灭绝过程

湖南慈利地区二叠系-三叠系界线附近地层非常发育,是探讨二叠纪-三叠纪之交生态系转变的良好区域。本研究通过对该地区康家坪剖面长兴组上部与大冶组下部地层进行系统采样、切片研究,在长兴组上部地层中发现278个类有孔虫,共鉴定出4属11种(含2个未定种)。这些类有孔虫在地层中的分布表明类有孔虫在二叠纪末经历了一次突变式的灭绝过程,其灭绝层位位于长兴组顶部的生物碎屑灰岩与大冶组底部的微生物岩之交界线处。该研究不仅丰富了康家坪剖面在这一关键时期的生物群面貌,而且也为二叠纪末的生物灭绝事件的深入研究提供了新的材料。

名刊速览

巧克力山是菲律宾保和地区一种奇特的地质构造。根据最新的准确调查，在大于50平方千米的地区上分布着1776座山丘。它们被～种绿草所覆盖，这种草在干燥季节会变成褐色，就像巧克力的颜色一样，这些山也因此而得名。这些山丘由从上新世到更新世，从小到大，从沙质到坚固的海相灰岩组成。这些岩石含有大量海洋有孔虫类、珊瑚虫、软体动物和藻类的化石。

内蒙古苏尼特右旗德言其庙剖面二叠纪■类动物群

二叠纪时,内蒙古中部地区位于特提斯古生物地理区北缘的过渡带,是海相暖水动物群与冷水动物群的交汇地带,对研究特提斯古生物地理区系的演化有重要作用。但由于受到后期构造作用的影响,内蒙古中部地区二叠纪灰岩地层出露并不连续,研究程度较差。近年来,我们获取了东部苏尼特右旗德言其庙地区阿木山组、哲斯组丰富的[虫筳]类化石材料。通过对[虫筳]类化石的系统研究,共鉴定出?类14属39种。识别出4个[虫筳]类化石带,由老至新依次为Pseudofusulina acuteata富集带、Chalaroschwagerina inflata延限带、Parafusulina jilegensis-Rugosofusulina intermedia组合带以及Chusenella conicocylindrica富集带,对应时间为早二叠世萨克马尔期至中二叠世罗德期。这一[虫筳]类动物群的深入研究结果是对北方过渡带海相动物群研究的重要补充。

Neogene oxygen isotopic stratigraphy,ODP Site 1148,northern South China Sea

A detailed stable isotopic study based on benthic foraminifera from 1165 samples of ODP Site 1148 (18° 50.17.3′N, 116° 33.93′E, water depth 3308.3 m), northern South China Sea,provides an excellent oxygen isotopic record with an average resolution of 30 ka. It contains the most continuous δ18O data with highest resolution for the whole Neogene sequence in the world.The δ 18O curve shows a step-like increasing upwards and records 5 increases, 3 decreases and 2stable stages during the Neogene, reflecting the general trend of global coolin9. Among these events the δ18O decrease at 17.2-14.5 Ma, and two δ18O increases at 14.5-13.6 and 3.0-2.4Ma are most marked and globally comparable. The intervals at 13.6-10.2 and 6.0-3.0 Ma with the lowest-amplitude and least fluctuation in δ18O represent the most stable bottom water periods for the South China Sea.

A record of Miocene carbon excursions in the South China Sea

High-resolution δ13C records are presented for the Miocene benthic foraminifers Cibici doides wuellerstorfi and C. kullenbergi (24-5 Ma) and the planktonic foraminifer Globigerinoides sacculifer (18-5 Ma) from ODP Site 1148A (18° 50.17′N, 116° 33.93′E, water depth 3308.3 m),northern South China Sea. The general pattern of parallel benthic and planktonic δ13C shows a decrease trend of δ13C values from the early-middle Miocene to the middle-late Miocene. Two dis tinct δ13C positive excursions at 23.1-22.2 and 17.3-13.6 Ma, and two negative excursions at 10.2-9.4 and 6.9-6.2 Ma have been recognized. All these events are cosmopolitan, providing the good data for the stratigraphic correlation of the South China Sea with the global oceans as well as for studying the changes of the global carbon reservoir and its corresponding climate.

Evolution of planktonic foraminifera and thermocline in the southern South China Sea since 12 Ma (ODP-184,Site 1143)

Down-core variation in planktonic foraminifera (PF) at Site 1143 (ODP 184) has dis closed the evolution of upper water-column structure over the last 12 Ma in the southern South China Sea. In the early Late Miocene (～10.6-7.8 Ma), there existed a lower percentage of total deep-dwelling species, reflecting a water thermocline deeper than that in the Middle Miocene,which resulted from the closure of Indonesian seaway and relevant intensification of the equatorial warm current. After the increase in deep-dwelling PF and the rising of thermocline during the late Late Miocene (7.6-6.4 Ma), the total deep-dwelling species decreased gradually from late Late Miocene (6.4 Ma) to the Pliocene, implying the deepening of water thermocline. The evolution of thermocline depth in the southern South China Sea reflected by the PF at Site 1143 might be a good indicator of the change of west Pacific 'warm pool'.

Influence of foraminifera on formation and occurrence characteristics of natural gas hydrates in fine-grained sediments from Shenhu area, South China Sea

Marine gas hydrates accumulate primarily in coarse-grained, high-permeability layers; however, highly saturated natural gas hydrates have been discovered in the fine-grained sediments of Shenhu area, South China Sea(SCS). This may be explained by key factors, such as the great abundance of foraminifera shells. In this paper, by analyzing the SCS foraminifera structure and performing hydrate formation experiments in the foraminifera shells, the contribution of foraminifera to hydrate accumulation in the SCS was investigated from a microscopic point of view. Simulations of hydrate formation were carried out in both pure SCS foraminifera shells and the host sediments. Pore structures in typical foraminifera were studied by use of micro-focus X-ray computed tomography(CT) and scanning electron microscopy(SEM). Hydrate growth and occurrence characteristics in the foraminifera shells were observed in-situ. The results showed that the presence of foraminifera significantly enhanced the effective porosity of the SCS sediments. Moreover, while the hydrates grew preferentially in the chambers of the coarse-grained foraminifera by adhering to the inner walls of the foraminifera shells, no apparent hydrate accumulation was observed in the fine-grained or argillaceous matrix. These findings provide a basis for further studies on the accumulation mechanism of hydrates and physical properties of hydrate reservoir in the South China Sea.

High-resolution records of thermocline in the Okinawa Trough since about 10000 aBP

The present paper uses planktonic foraminifera and their stableisotopes to study the changes in the depth of thermocline (DOT) in the Okinawa Trough since the last 10000 a based on the analysis of Core B-3GC in the northern Okinawa Trough, together with that of the core in the southern Okinawa Trough. As results show, the thermocline was shallow before 6400 aBP, and deepened afterward, then became shallow again from 4000 to 2000 aBP. The DOT fluctuations display a positive correlation with those of sea surface temperature (SST). In addition, the changes in the northern Okinawa Trough are similar to those in the southern trough, implying a possible connection with the variation of the Kuroshio Current. The changes of SST and DOT suggest that the Kuroshio Current changed its intensity or main axis from 4000 to 2000 aBP and around about 6400 aBP respectively. Moreover, the changes of DOT from 8200 to 6400 aBP may indicate a gradual intensification of the Kuroshio Current.

Microfossil assemblage characteristics in Core B10 and implication for paleoenvironmental evolution in the southern Yellow Sea

Microfossil assemblage and pollen zone characteristics in Core B10 recorded the history of environmental changes in the southern Yellow Sea since Wiirm Subinterglaciation. Environmental variations reflected by these glacial and interglacial sediments coincide with general characteristics of paleoenvironmental and sedimentary changes in the Yellow Sea. In the section of 550-520 cm, microfossil foraminifera have low abundance and diversity, and pollens are composed mainly of those of herbaceous vegetation, indicating climate change during Wiirm Subinterglaciation. In the section of 520-140 cm, the changes from a few microfossils to no microfossils reflect the sedimentary environment variation from coastal to terrestrial facies. Paleoclimate reflected by pollen also underwent the changes from conifer-broadleaf mixed forest to grassland, indicating the climate changes from temperate and cool type to warm and dry one. In the section of 140-0 cm, the general microfossil characteristics are the gradual increase in abundance with most species being neritic species, the major pollen being ligneous pollen and the rapid increase in small Hystrichosphaera content, which indicates that the air temperature increased and the sea level gradually rose.

ENREF 33形态测量学(Morphometrics)常用方法及其在微体古生物学中的应用

形态测量学用定量化的方法和手段描述、研究对象形态特征。几何形态测量学是形态测量学的分支,用界标点或轮廓线等标识研究对象的形态,并运用多变量运算进行量化分析和判别。形态测量学方法在生物学与古生物学领域的应用日益广泛,在生物的个体发育、系统演化、类群判别等方面均可发挥重要作用。本文重点介绍了目前在形态测量学中常用的数据类型、分析方法与步骤,即线性距离、界标点、轮廓线等数据类型的获取,普鲁克迭加、傅里叶转换、特征形状分析与增强特征形状分析等数据转换方法,以及主变量分析、典型变量分析等常用多变量线性回归方法的原理与分析过程。选择以类有孔虫个体发育与类群鉴定中几何形态测量学的应用为例,解释最常用的多变量线性回归方法——主成分分析与典型变量分析的应用与结果剖析。

Foraminiferal biostratigraphy of the Miocene Qom Formation, northwest of the Qom, Central Iran

在 Dochah 附近，在 Qom 形成的类型区域，中央伊朗，中新世部分在远洋的外形被开发。从 894.1 米厚， a 到这节的 e 成员， 152 件样品被收集。丰富的 planktonic 有孔虫类让我们相关有全球 planktonic 有孔虫类 biozonations 的学习节。在学习节的有孔虫类的高差异允许我们使学习继任适应全球 biozonations。27 个类和 34 种从 Dochah 节第一次被报导。首先，在这节的上面的部分的 Praeorbulina sicana 和 Praeorbulina transitoria 的报告导致了 Praeorbulina sicana 的识别有晚迟了的 Burdigalian 年龄的更低的出现 subzone (M5a ) biozone。