第四纪甲虫研究方法及意义

第四纪甲虫的研究在国外已开展多年,形成了一套完整的方法,而在我国几乎为一空白。第四纪甲虫研究方法一般包括如下几个步骤：野外采样,实验室分离,标本保存,标本鉴定,结果分析。第四纪甲虫研究的意义主要表现在如下三个方面：重建古气候、恢复昆虫地理史和第四纪考古。     

闽南第四纪晚期沉积硅藻组合与古环境研究

对闽南泉州湾外台湾海峡西部756柱状剖面和厦门岛GT剖面岩心进行系统的硅藻分析研究,获得硅藻161种和变种。根据剖面硅藻组合特征变化,结合聚类分析和最优分割的计算机运算结果,756柱状剖面自下而上可以划分为5个硅藻带,GT剖面自下而上可以划分为6个硅藻带。根据硅藻组合序列,探讨其第四纪晚期古环境的演变。     

东海陆缘(浙南段)晚第四纪硅藻的发现及古环境分析

东海陆缘(浙南段)温州沿海以往第四纪沉积已开展了一些研究,见有丰富的有孔虫、孢粉等生物化石,但未发现硅藻。本项研究在温州CH6井、台州CH5井岩心中发现了大量硅藻化石,本文以温州CH6井丰富的硅藻化石为依据,建立了晚第四纪硅藻组合序列,划分为12个硅藻带,并恢复其古环境演替,根据四个AMS ^14C年代数据,其时代属早、中全新世。     

福建沿岸晚第四纪孢粉,硅藻组合及其古环境意义

通过对福建沿岸８个钻孔的孢粉、硅藻的综合分析,发现晚第四纪地层中有８个综合孢粉组合带与７个硅藻阶段。结合古地磁和１４Ｃ测年资料认为,该地区晚第四纪地层划分为晚更新世中、晚期（早大理冰期、大理亚间冰期、晚大理冰期）和全新世（早期、早中期、晚中期、晚期）。气候变迁序列为冷而干燥→暖而湿→冷而干燥→温暖稍干→暖而湿→热暖潮湿→温暖略干→温暖湿润。据古环境分析认为有七次海侵（或海进）,且各次海侵（或海进）的影响范围差异较大     

江西九江第四纪红土中的植物硅酸体及孢粉

九江第四纪红土中植物硅酸体、孢粉记录表明：该地红土是湿热环境下的产物;红土形成时期发育了亚热带常绿落叶阔叶类植被;九江第四纪红土中植物硅酸体保存不如中国北方黄土。古土壤A层被侵蚀及铁、铝氧化物的高含量可能是造成红土中植物硅酸体保存不佳的主要原因;亚热带植被中乔木类植物硅酸体抗溶解力弱;经工土中禾本科植物夺地 体保存与风化指标、全有机碳成正相关;禾本科植物硅酸体总量自剖面底部（网纹红土）一顶部（褐黄土层）逐渐增多,可能暗示中更新世晚期以来存在较为普遍的气候恶化趋势,气修总体向变冷、变干方向发展;红土剖面５m及３.0左右古土壤Ａ层的出现及剖面风化指标与元素地球化学特征表明：该地红土经历了堆积与风化同时进行的加积型风化过程。     

火烧迹地木炭对兴安落叶松种子萌发的影响

通过对大兴安岭兴安落叶松火烧迹地木炭的野外调查和取样,分别选取不同来源（兴安落叶松,白桦,灌木,草本）的木炭,以及不同火烧时间（当年,1年,4年,5年）的木炭,研究不同种类木炭浸提液,以及相同种类不同火烧时间木炭浸提液对兴安落叶松种子萌发的影响。研究结果发现,不同来源、不同时间的木炭对兴安落叶松种子的萌发均有显著性的影响,但作用力的方向和大小也各不相同,这说明木炭对种子萌发的影响因素非常复杂。     

华北泥河湾盆地植被、气候与早期人类生存环境研究进展

中国北方泥河湾盆地可以与非洲奥杜威峡谷相媲美,它们具有十分相似的地质演化过程,这里河湖相沉积发育,并且蕴藏着丰富的古生物化石和大量古人类遗迹,是研究东亚早期人类生存环境变化的重要区域。基于前人积累的晚上新世以来植被、气候及早期人类生存环境的大量研究资料,经分析发现在大约2.6Ma(百万年),泥河湾盆地的植被由阔叶林转变为以针叶林为主;大约1.92 Ma以后,植被以温带森林-草原(主要是松属、蒿属及藜科)/温带草原(主要是蒿属和禾本科等)为主。通过对比发现,晚上新世以来中国北方从西部到中部,由森林转变为以森林-草原为主的植被类型出现的时段呈现明显的阶梯型。此外,泥河湾盆地气候出现了13个冷暖旋回, 15个干湿旋回,显著的冷干事件发生在2.8 Ma、2.6 Ma、1.92 Ma及143.8 ka (千年),湿润事件发生在43、32和6.6 ka。早期人类生活在森林-草原或以草原为主的植被环境中,气候冷暖干湿波动较大,水源丰富,大量哺乳动物共存。建议在建立泥河湾人类遗址更为精细地层的年代框架下,开展古气候温度与降水参数的定量化研究,将有助于精准重建古人类生存环境及揭示其变化规律。     

泥河湾盆地第四纪哺乳动物群概览及若干新认识

泥河湾盆地最初以其广泛分布的含化石河湖相地层而受关注,并以其丰富的哺乳动物化石而著称于世,而今,泥河湾盆地已成为世界著名旧石器考古重地和研究第四纪地质古生物的重要场所。狭义泥河湾动物群（或下沙沟动物群）是我国北方早更新世的标准动物群,其古地磁年龄是2.2-1.7 MaBP。随着地层古生物工作的深入开展,盆地内也发现了若干中-晚更新世化石点;丁家堡水库全新统中发现的象颊齿,之前被鉴定为亚洲象,新的测年数据表明其时代大于5万年,依据牙齿测量数据和形态特征,本研究将其归入诺氏古菱齿象。目前已在泥河湾盆地发现百余个化石地点,鉴定出236种（包括未定属种）哺乳动物,分属于8目、32科和121属,其中38个属种（包括亚种）最初是以泥河湾化石材料而建立。总而言之,泥河湾盆地哺乳动物化石以早更新世者居多,并且化石材料保存完好;有些属种在欧亚大陆古北区第四纪哺乳动物群形成过程中发挥过重要作用,例如早期猛犸象、披毛犀、野牛及真枝角鹿等,还有直隶狼、貉及各种真马。泥河湾盆地由于河流和断层切割以及沉积相变等原因,导致各个化石点及史前考古遗址地层难以直接对比,更难全窥盆地内动物群演化的整体脉络;新的生物地层对比...     

Fossil wood charcoal assemblages from Elands Bay Cave, South Africa: implications for Late Quaternary vegetation and climates in the winter-rainfall fynbos biome

Aim The aim of this paper is to analyse fossil charcoal deposits, largely identified to the species level and spanning a sequence from the late Holocene to < 40,000 BP , in order to reconstruct Late Quaternary vegetation and climatic patterns in the western (winter-rainfall) fynbos biome of South Africa. Location The charcoals were excavated from the Elands Bay Cave (32°19S, 18°20E) on the semiarid (200–250 mmyr^?1), winter-rainfall coastline of the western fynbos biome. Methods Patterns in the charcoal data set over time were sought by manual sorting of the charcoal×sample matrix, as well as by subjecting the data to multivariate analysis. Palaeoclimatic reconstruction was attempted by comparing the climatic controls on contemporary vegetation communities that resembled the fossil assemblages. Charcoal diversity was modelled using sample age and number of charcoal fragments as explanatory variables. Results The fossil assemblages ranged from xeric communities (similar to those presently occurring at the site) during the Holocene, to more mesic thicket and fynbos vegetation in the terminal Pleistocene, to Afromontane forest and riverine woodland communities after about 18,000 BP . Diversity of the charcoal samples increased monotonically with increasing sample age. Main conclusions The results suggest that, unlike the eastern fynbos biome, which is under fundamentally different climatic controls, soil moisture conditions in the western part of the biome were higher in the Last Glacial than during the Holocene. This scenario may help to explain the higher regional richness and associated diversification in the western than eastern part of the biome.     

广西化石猩猩牙齿釉质厚度研究

华南和东南亚发现大量更新世的猩猩牙齿化石。本研究应用CT扫描三维重建的技术方法研究了广西更新世化石猩猩牙齿釉质厚度,并与现生类人猿、现代人、化石类人猿以及早期人类进行比较分析。结果显示:广西猩猩同类牙齿的釉质厚度与牙齿大小相关性很小;臼齿和前臼齿釉质厚度在上下颌之间不存在显著性差异;来自广西不同地区的猩猩化石牙釉质厚度无显著差异。与早期人科成员相比,广西猩猩的牙釉质相对较薄,平均与相对釉质厚度值都明显小于南方古猿、傍人。与早期人属相比,小于直立人、尼人以及非洲和欧洲的早期人属化石。与现代人和现生灵长类相比,广西化石猩猩釉质厚度明显大于大部分猴类和非洲大猿;平均釉质厚度稍大于现生猩猩,而与现代人更为接近;相对釉质厚度小于现代人,而与现生猩猩差异不大,都属于偏厚型釉质。本文讨论了釉质厚度与系统分类演化、食性适应的相关问题,作者推测釉质厚度可能是物种的特征属性,与牙齿功能适应有密切关联。     

江汉平原47号钻孔中的化石硅藻及其在古环境分析上的意义

江汉平原47号钻孔,位于湖北省江汉平原的江陵县,在其上段的46.6-2.2m层位上,有丰富的化石硅藻,约有26属148种,其中绝大多数是现存的淡水种类,并以附生性、沿岸带和浅水性的种类为主。种类较多的属有:Navicula(28种)、Cymbella(23种)、Achnanthes(15种)、Gomphonema(14种)和Eunotia(13种)。主要种类有Gomphonema tropicale var. nonpunctatum、Cyclotella comta、Cocconeis placemula vat. lineata和Stephanodiscus dubius等。硅藻中的种数(种/层)和数量(个/每克干沉积物)经历了一个从无到有、由少到多再逐渐减少直至消失的过程。这反映了水体环境也相应地经历了一个漫长的变迁过程:河流(可能是长江古道)→边滩和河漫滩→泛滥平原的积水洼地(湖泊或沼泽)→水体变深加宽→水体消失。从不同沉积相中各种类型(适酸碱度不同)的硅藻比例(即硅藻种谱),可以推测当时水体的酸碱度的变化不大,在中性或中性偏碱的范围。由化石硅藻并结合孢粉的矿物分析,可以推测当时硅藻大量生长繁殖时期的水温较凉,气候可能偏冷。硅藻的数量与沉积物的平均粒度呈明显的相关性,硅藻的种数与沉积物的平均粒度也呈明显的相关性。     

在中国云南发现狒狒化石

现存狒狒类(Papionin)生活于非洲(如Papio和Theropithoan)、亚洲(如Macaca)和北非(M.sylvanas)。在上新世和更新世,Theropithecus经历了从非洲到亚洲的扩散过程,在印度发现了类似化石。这次在云南中甸金沙江附近发现的下更新世狒狒化石(Papio)证明,如同亚洲猕猴和现代人类祖先一样,非洲狒狒类(Papio和Theropithecus)在同一时期从非洲扩散到亚洲。所不同的是它们没有像猕猴和人类一样生存下来。这次化石的发现对于研究以下生物学问题提供了重要依据1)探讨旧大陆猴类在上新—更新世从非洲到亚洲的扩散过程;2)研究不同旧大陆猴类的进化和环境适应性;3)为现代人类祖先在非洲—亚大陆的扩散研究提供证据;4)由于化石产地包括有人类祖先和其他动物的化石,因此,狒狒在亚洲的生态适应研究将为探讨人类在同一时期的生态适应提供证据。     

现生太行山猕猴与猕猴化石骨指数的比较

为探讨现生太行山猕猴与猕猴化石骨指数的差异,对太行山猕猴与广西崇左早更新世猕猴化石的肢间指数(Intermembral index,IM)、臂指数(Brachial index,BI)、股指数(Crural index,CI)和股骨粗壮指数(Robusticity index,RI)等指数进行比较。结果表明,猕猴化石IM值(96)高于太行山猕猴,BI值(94.5)和CI值(88.5)均低于太行山猕猴,推测该猕猴化石在早更新世时期可能地栖生活,适合于陆地四足行走,同时也验证了太行山猕猴主要为半树栖生活。结合对猕猴化石伴生哺乳动物习性的分析,推测广西崇左早更新世的气候温暖潮湿并有一定的水域,植被以森林和灌木为主,有局部的草地或草坡,其自然环境非常适宜高等灵长类生息繁衍。     

Global Completeness of the Bat Fossil Record

Bats are unique among mammals in their use of powered flight and their widespread capacity for laryngeal echolocation. Understanding how and when these and other abilities evolved could be improved by examining the bat fossil record. However, the fossil record of bats is commonly believed to be very poor. Quantitative analyses of this record have rarely been attempted, so it has been difficult to gauge just how depauperate the bat fossil record really is. A crucial step in analyzing the quality of the fossil record is to be able to accurately estimate completeness. Measures of completeness of the fossil record have important consequences for our understanding of evolutionary rates and patterns among bats. In this study, we applied previously developed statistical methods of analyzing completeness to the bat fossil record. The main utility of these methods over others used to study completeness is their independence from phylogeny. This phylogenetic-independence is desirable, given the recent state of flux in the higher-level phylogenetic relationships of bats. All known fossil bat genera were tabulated at the geologic stage or sub-epoch level. This binning strategy allowed an estimate of the extinction rate for each bat genus per bin. Extinction rate—together with per-genus estimates of preservation probability and original temporal distributions—was used to calculate completeness. At the genus level, the bat fossil record is estimated to be 12% complete. Within the order, Pteropodidae is missing most of its fossil history, while Rhinolophoidea and Vespertilionoidea are missing the least. These results suggest that 88% of bats that existed never left a fossil record, and that the fossil record of bats is indeed poor. Much of the taxonomic and evolutionary history of bats has yet to be uncovered.     

山东山旺中新世硅藻及其环境的模糊数学聚类分析

本文侧重于山东山旺中新世硅藻盆地的古环境分析。笔者从平面上和剖面上分别采集并分析了硅藻土样品,根据样品中硅藻植物化石的分布,综合分析了剖面 No.1、No.4、No.5的化石组合。采用了模糊数学聚类分析法,直观地显示出浮游型 Melosira 组合和底栖附生型 Cymbella-Fragilaria 组合在时间和空间上的演变,进一步反映山旺湖盆湖水的深浅及湖盆范围之变化。对具有颜色深浅不同所显示水平纹层的硅藻土作了微层分析,结合电镜扫描及氧同位素值的证据,认为此硅藻土的深浅纹层为季纹层。     

Fossil history of the Menispermaceae (Ranunculales)

The Menispermaceae family (Ranunculales) includes more than 500 extant species. Climbers represent the majority of this family, and these plants are now distributed in all of the tropical and subtropical regions of Americas, Asia and Africa. Their endocarps show a characteristic shape that is easily identified in the fossil floras. Numerous fossil leaves are also mentioned in the literature, but the methods for identifying these fossils are often outdated and need revision. Four tribes of Menispermaceae are present in the fossil record, including Fibraureae, Menispermeae, Pachygoneae and Tinosporeae. Only the Anomospermeae are potentially lacking. The Menispermaceae appear in the Palaeocene, and are common in the Eocene, of Europe and in North America as represented by endocarps and locule-casts. The species of this age show morphological diversification, corresponding with the current familial diversity. A few specimens from the Cretaceous period could be part of this Angiosperm family. Fossils after the Eocene are scarcer, despite several relatively rich outcrops. The maximal expansion of the Menispermaceae during the Palaeocene/Eocene limit correlates with the thermal optimum of the early Tertiary and also parallels the maximal expansion of tropical and subtropical floras. The relative richness of the Eocene era in Menispermaceae could be a consequence of more intense sampling in some regions. The bias in tribe representation can be explained by evolution, ecology or taphonomic hypotheses.