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1.
本文以Albian-Campanian的钙质超微化石为例,介绍了一种描述生物地理学研究的新方法--运用计算机绘制化石种的分布图(包括平面图和立体图两种),并运用这一方法对该时间段的近200个种进行了具体研究,归纳出六种分布类型,即:广布型,南半球分布型,北半球分布型,赤道海域缺失型,赤道海域分布型,迁移型。并且对每个种在这一时间段中的分布了具体阐述。  相似文献   

2.
渤海海域新近纪普遍发育河流相沉积,近年大量探井揭示渤海海域东南部地区新近系发育湖相、浅水三角洲相以及河流相几种沉积类型。本文对东南部地区新近纪古生物特征展开系统研究,在此基础之上结合丰富的岩心资料总结了渤海海域新近纪湖盆萎缩期河湖过渡带各种典型沉积相类型的古生物分布特征。研究表明:湖相地层古生物门类丰富,发现了藻类,孢粉以及无脊椎动物等类型,化石丰度高,尤其是藻类化石占有重要比重,局部含量达90%以上。三角洲前缘化石门类多,但是丰度较滨浅湖低。三角洲平原相,孢粉较藻类化石含量具有明显优势,尤其是草本植物类型含量高,并且植物碎屑,根系,碳屑常见。河流相化石相对贫乏。在此基础上对渤海海域东南部新近系古环境演化开展研究,结果表明新近纪湖盆萎缩整体呈先扩张再衰退的变化过程,馆陶组中晚期以后湖盆逐渐扩张,到明化镇组下段沉积时期古湖盆最为发育,明化镇组上段时期古湖盆逐渐收缩。  相似文献   

3.
苑坚 《化石》2003,(3):7-7
我国专家首次运用物探手段在四川省自贡市大山铺寻找恐龙化石 ,在基本确定了恐龙化石层的分布、化石富集区等情况后 ,日前已成功发掘出一具深处 9米地层下的恐龙化石。四川自贡大山铺中侏罗纪恐龙化石群产地是一处享有国际声誉的地质古生物遗址 ,化石藏量之大、属种之多、保存之好在世界相同地质年代的恐龙产地中首屈一指 ,填补了世界上中侏罗纪恐龙化石缺乏的薄弱环节 ,对研究恐龙的早中期演化具有十分重要的意义。自贡恐龙博物馆副馆长彭光照介绍说 ,这一化石群的二期开发工程的关键性技术难题是要弄清待建区域 (8.9平方公里 )内 ,恐龙化…  相似文献   

4.
对1978年4~5月太平洋中部热带水域和1984年4~7月东海外海黑潮流域调查期间采集到的底灯鱼属鱼类的仔稚鱼样品进行分类鉴定,共鉴定出了七星底灯鱼、耀眼底灯鱼、带底灯鱼、冰底灯鱼和巴拿马底灯鱼5种仔稚鱼,描述了其个体的发育形态,构建了种类的分类检索表.首次记录了巴拿马底灯鱼在我国东海外海的分布,以及冰底灯鱼在太平洋赤道附近海域(1°10′N,171°30′W;水深5 465 m)的分布,填补了这两个种类在我国及其邻近海域分布记录上的空白.  相似文献   

5.
横断山地区石炭纪和二叠纪有孔虫   总被引:9,自引:4,他引:5  
横断山地区石炭纪和二叠纪海相沉积分布非常广泛,在早石炭世杜内期至晚二叠世各沉积中均含有大量有孔虫化石,其中尤以维宪期和长兴期沉积中的有孔虫化石最为丰富和保存极佳。本文描述了较为常见和特征的分子共11科30属65种,其中8个为新种,根据分析和比较,横断山地区石炭纪和二叠纪有孔虫动物群的组合面貌和特征与我国华南地区同期地层中所见有孔虫动物基本一致,同属“南方型”生物群,同时也与特提斯海域同期地层中有孔虫动物群非常近似,因此可以说明横断山地区当时的海水不仅与我国华南海域及特提斯海域都是相通的,同时都繁衍着大致相同的有孔虫动物群,它们均生活在温暖和盐度较为正常的浅海水域中。  相似文献   

6.
《化石》1999,(3)
中间这五幅框图是五类不同的动物化石。请您首先写出它们各是什么化石(只写出大的化石类别,不写具体属种名称)。左边五个框是这五大类化石所属的动物“门”,从下到上是由简单到复杂,由低级到高级,请您联线表明它们的归属。右边五个框里写的是这五大类化石分布的时代...  相似文献   

7.
胡亮 《生物多样性》2021,29(10):1403
海洋底栖贝类是海洋底栖无脊椎动物的重要代表。福建平潭岛地处台湾海峡西岸北部, 是中国大陆距台湾岛最近之处, 其海域内的底栖贝类区系对了解台湾海峡及其附近海域的生态环境和底栖生物地理格局具有重要意义。本文基于对2015-2018年间中山大学国土资源与环境系在平潭岛海域采集的3,346号底栖贝类标本的鉴定, 结合已发表文献整理出了平潭岛海域底栖贝类名录, 并梳理了各物种在中国近海的地理分布类型。结果显示, 本研究所采标本分属58科122属161种, 其中47种为平潭岛海域新记录。结合历史文献记录, 平潭岛海域共有底栖贝类98科244属395种。其中93.7%的种类在南海亦有分布, 82.0%的种类在东海有分布, 31.1%的种类在黄渤海有分布, 42.3%的种类在台湾岛东部海域有分布。南海-东海分布型种类占区系总种数的49.9%; 其次为南海-黄渤海分布型(27.6%)和南海-台湾海峡分布型(16.2%)。分布限于台湾海峡及其以北的种类仅占总种数的6.3%。研究结果表明, 平潭岛海域底栖贝类区系具典型的亚热带性质, 暖水性种类和广温性种类占主要优势, 与南海北部和东海大陆沿岸地区的关系密切, 与台湾岛周边海域的联系相对较弱。  相似文献   

8.
本文记述的是在禄丰腊玛古猿化石产地发现的长臂猿类化石,它是一种与上猿较为相似而又具有一些进步性质的长臂猿类。它的发现从根本上改变了晚中新世此类化石记录稀少的状况,使我们对这一时期的长臂猿类有了新的认识;同时,对现生长臂猿起源的研究提供了较为充分的化石依据。鉴于它的形态特征和地史分布,作者把它订为一新属新种Laccopithecusrobussus gen.et sp.nov.  相似文献   

9.
随着古生物原始资料的不断积累,通过建立数据库对化石资料进行搜集和管理已成为一种趋势。丰富的原始数据,使我们进行古生物地理研究,特别是大尺度定量古生物地理研究成为可能。文章从化石数据库的建立开始,详细地介绍一种古生物地理学定量研究的方法。通过对二叠纪Roadian-Wordian期全球381个腕足动物属分布数据的聚类分析,区分出4个腕足动物生物域(北方域、冈瓦纳域、泛大洋域、古赤道域)和9个生物区[东北欧区(Northeast European)、维尔科累马区(Verkolyma)、格兰丁区(Grandian)、华夏区(Cathaysian)、基墨里区(Cim-merian)]、中蒙日区(Sino-Mongolian-Japanese)、泛大洋区(Panthalassan)、西澳区(Westralian)和澳纽区(Aus-trazean),这4个域和9个区的生物地理区系特征与它们当时的古地理位置基本吻合。同时,多维尺度分析表明,与纬度相关的温度梯度是控制腕足动物分布的主要因素,古地理屏障和洋流可能在腕足动物空间分布模式的形成中同样扮演着重要角色。  相似文献   

10.
应用光学显微镜对分布于安徽省琅琊山特殊生境条件下的2种特有濒危植物琅琊榆(Ulmus chenmoui Cheng)、醉翁榆(U.gaussenii Cheng)以及广布种白榆(U.pumila Linn.)的花粉形态进行了观察和比较研究。结果表明:琅琊榆和醉翁榆花粉粒扁球形或近球形,极面观上多为近圆形,或为规则和不规则的多边形,萌发孔主要是4—6孔,位于赤道或赤道附近。外壁纹饰主要是疣状纹饰。同时研究了采样点的地理位置、海拔高度、年降水量、年积温及生境等,特别提供了3月份的气候因子,得出这些花粉分布区的主要生态因子,为利用地层中相应化石花粉研究琅琊山地区古植被、古环境及气候变迁提供了现代孢粉学资料和依据,也为两个特有种的现代地理分布提供了科学依据。  相似文献   

11.
根据文献资料和标本馆及化石记录,讨论了壳斗科栲属植物的现代分布和地史分布。现代栲属植物有110~134种,主要分布在东亚及东南亚,其中印度支那地区有82种栲属植物,是世界栲属植物分布最集中的地区,马来西亚地区是栲属特有种最丰富的事实是支持马来西亚地区与其它地区的区系交流十分有限的论据。中国栲属植物最丰富的地区是滇黔桂地区(29种)。栲属植物现代多样化中心在马来西亚和中南半岛。排除Chrysolepis后,栲属的分布类型应属热带亚洲分布。栲属在地质历史上有着比现在广泛的分布,最早、最可靠的栲属化石记录发现于北美始新世地层,欧洲和日本始新世也有栲属的化石记录,化石记录表明栲属起源的时间不晚于古新世,所有的壳斗科及栲属的化石都发现于北半球,现代分布也主要在北半球,壳斗科及栲属起源于北半球可以确认,由于化石证据与现代植物学的研究结果有较大差异以及关键地区化石证据的不足,具体的起源地尚不能肯定。  相似文献   

12.
David G. Frey 《Hydrobiologia》1993,262(3):133-144
Examination of many species of Pleuroxus from the entire World has revealed a major dichotomy in morphology, one line related to aduncus: the other to laevis both from Europe. Pleuroxus trigonellus (the type species of the genus) and Peracantha truncata are in two other distinct lines. The new subgenus Tylopleuroxus is proposed for the species related to aduncus, and the subgenus Picripleuroxus for those related to laevis. Tylopleuroxus is primarily Southern Hemisphere in distribution, Picripleuroxus primarily Northern Hemisphere. Evidence thus far suggests that probably most, perhaps all, of the taxa are confined to single continents or land masses. Deceased  相似文献   

13.
通观种的繁殖区资料后,将文献报导的253种四川非雀形目鸟类分为11个分布类型:极地型,北半球北部型,欧亚北部型,中亚型,青藏高地型,横断-喜马拉雅山地型,中国东北及其邻区型,中国季风区型,南亚及东南亚型,东半球热带亚热带型,环球热带亚热带型;进而对有关分布型的划分作了研讨。文东对此区系的结构特点作了叙述。  相似文献   

14.
Brown algae of the order Laminariales, commonly referred to as kelps, are the largest and most productive primary producers in the coastal inshore environment. The genus Ecklonia (Lessoniaceae, Phaeophyceae) consists of seven species with four species in the Northern Hemisphere and three in the Southern Hemisphere. It was recently transferred to the family Lessoniaceae based on phylogenetic analyses of nuclear and chloroplastic markers, though the type of the genus was not included and its relationship with allied genera Eckloniopsis and Eisenia remained unresolved. The present study is the first to produce a phylogeny focussed on the genus Ecklonia. It included sequences from nuclear, mitochondrial, and chloroplastic DNA, for most of the distribution range of the three current Southern Hemisphere species (Ecklonia radiata, Ecklonia maxima, and a sample of a putative Ecklonia brevipes specimen), sequences for East Asiatic species (Ecklonia cava, Ecklonia kurome, and Ecklonia stolonifera), as well as the closely related genera Eckloniopsis and Eisenia. Results confirmed E. radiata and E. maxima as two distinct species in South Africa, E. radiata as a single species throughout the Southern Hemisphere (in South Africa, Australia, and New Zealand) and East Asiatic species as a distinct lineage from the Southern Hemisphere clade. Results further pointed out a close sister relationship between Eckloniopsis radicosa and two Eisenia species (including the type species: Eisenia arborea) to the genus Ecklonia suggesting that the genera Eckloniopsis and Eisenia are superfluous.  相似文献   

15.
The continental coasts and remote islands in the high-latitude Southern Hemisphere, including the subantarctic region, are characterized by many endemic species, high abundance of taxa, and intermediate levels of biodiversity. The macroalgal flora of these locations has received relatively little attention. Filamentous green algae are prolific in the intertidal of southern islands, but the taxonomy, distribution, and evolutionary history of these taxa are yet to be fully explored, mostly due to the difficulty of access to some of these locations. In this study, we examined specimens of the order Cladophorales from various locations in the high-latitude Southern Hemisphere including the subantarctic (the Auckland Islands, Bounty Islands, Campbell Island, Macquarie Island, and Kerguelen Islands), as well as mainland New Zealand, the Chatham Islands, Chile, and Tasmania. The analyses of the rDNA sequences of the samples revealed the existence of two new clades in a phylogeny of the Cladophoraceae. One of these clades is described as the novel genus Vandenhoekia gen. nov., which contains three species that are branched or unbranched. The amended genus Rama is reinstated to accommodate the other clade, and contains four species, including the Northern Hemisphere “Cladophora rupestris.” In Rama both branched and unbranched morphologies are found. It is remarkable that gross morphology is not a predictor for generic affiliations in these algae. This study illustrates that much can still be learned about diversity in the Cladophorales and highlights the importance of new collections, especially in novel locations.  相似文献   

16.
Wood anatomy ofCoriaria was surveyed to clarify generic features on the basis of 14 species collected from various regions of the World to cover the whole range of geographic distribution and habitual variation. Wood anatomy ofcoriaria is considerably uniform, and the species share a combination of the following features: 1) pores are thin-walled, polygonal in outline and mostly in multiples; 2) vessel elements and libriform fibers are very short; 3) perforation plates are exclusively simple; 4) intervessel pits are alternate; 5) vascular tracheids are present; 6) wood parenchyma is vasicentric and sometimes confluent; 7) rays are heterogeneous and large. Its species differ in several characters, such as distinctness of growth rings, pore size, pore patterns, type and abundance of wood parenchyma, and distinctness of storied structure. Comparisons among species indicate that the species of the Northern Hemisphere show a tendency toward having semi-ring porosity, while those of the Southern and Western Hemisphere have diffuse porosity. The other infrageneric variations appear to be related to different habits of the species rather than to geographic distribution. Small trees mostly have confluent and vasicentric parenchyma composed of fusiform cells and distinctly storied tissues, while shrubs and herbs have less abundant parenchyma which is vasicentric and comprises strands of two to four cells and indistinctly storied tissues.  相似文献   

17.
We propose the new genus Melyvonnea to accommodate species previously included in Mesophyllum having: a) perithallial protuberances that may branch and dominate over the encrusting base, b) monoecious gametophytes with gametangial conceptacles occasionally developed in superimposition, c) spheroid carposporangial chambers (lacking a central pedestal), and d) filaments lining canals of multiporate roofs composed of 3 to 5 cells with distinctively elongate basal cells. The new genus shares with Mesophyllum the development of a predominantly coaxial hypothallium. Melyvonnea presently accommodates three species in the Central Atlantic, viz. the generitype Melyvonnea canariensis (Foslie) comb. nov. from the Canary Islands, Melyvonnea erubescens (Foslie) comb. nov. ( = Mesophyllum incertum; type locality: Bermuda) from the western Atlantic, Melyvonnea aemulans (Foslie & Howe) comb. nov. from Puerto Rico, and one Indo‐Pacific species, Melyvonnea madagascariensis (Foslie) comb. nov. We also emend Mesophyllum Lemoine to encompass Northern Hemisphere species that lack the above apomorphies of Melyvonnea and in addition develop a central pedestal in carposporangial conceptacles (via dissolution of the surrounding cells) with gonimoblasts bending down to fill the empty space. Mesophyllum sensu stricto currently includes six species in the northeast Pacific (M. aleuticum, M. conchatum, M. crassiusculum, M. lamellatum, M. megagastri, M. vancouveriense), two species in the western Atlantic (M. mesomorphum and M. syntrophicum), and three species in the northeast Atlantic and the Mediterranean Sea (M. expansum, M. lichenoides, M. philippii). Gametophytic species of each genus show a mainly disjunct distribution being restricted to the tropics–subtropics (Melyvonnea) and the temperate waters of the Northern Hemisphere (Mesophyllum s.s.). This classification is supported by a consensus of studies of all well‐known species of Mesophyllum sensu Adey (1970), and is based on a phylogenetic analysis of morphological and anatomical characters in addition to molecular evidence.  相似文献   

18.
Terry L. Erwin 《ZooKeys》2013,(358):11-23
Among the extensive collections currently being made in Guyane (French Guiana), adults of a large and colorful species of pseudomorphine were encountered. The adults present, for the first time in the Western Hemisphere, elytra with a marked color pattern, and in addition a size considerably beyond that of the rest of the members of all other known genera in the Western Hemisphere. Both of these attributes, however, are well known in the Australian pseudomorphine fauna. This new species is described and illustrated and a revised key to the Western Hemisphere genera is included. The type locality of Guyanemorpha spectabilis gen. n., sp. n. is Guyane,Risquetout, PK20, 4.916°N, 52.516°W, 12m altitude.  相似文献   

19.
揭示区域物种组成随环境梯度的变化规律, 掌握物种多样性的周转过程及其与环境的耦合关系, 是理解物种多样性形成的生态过程的核心, 也是生物多样性保护和保护地网络构建的科学基础。神农架是众多古老、孑遗和特有植物的关键栖息地, 也是全球落叶木本植物最丰富的地区之一。然而, 我们对影响神农架植物物种周转并形成镶嵌格局的驱动因素知之甚少。本研究基于对神农架长期系统的植物群落物种调查数据, 通过广义相异模型(GDM)和偏回归分析等方法, 分析了气候差异、地理距离、人为干扰等因素对神农架植物物种周转的驱动效应。结果表明, 随着年均温(MAT)、≥ 0℃积温、≥ 10℃积温差异和地理距离增大, 植物β多样性显著增加, 而年均降水量(MAP)、距离道路距离及森林破碎化等人为干扰因素对植物β多样性无显著影响。地理距离、气候差异和人为干扰分别解释了物种相异性变异的28.75%、34.56%和12.55%, 其交互作用解释了变异的8.52%。地理距离、气候差异和人为干扰共同解释了物种相异性变异的43.47%。综上, 地理距离和温度分异是驱动神农架植物物种空间周转过程的关键因素。保护海拔梯度上植被的垂直带谱及复杂多样的地貌异质性, 是维持神农架物种周转生态过程的关键, 也是神农架国家公园建设乃至鄂西北保护地网络构建应关注的重点。  相似文献   

20.
狭义干蘑属(蘑菇目)概要及新的系统学处理   总被引:1,自引:0,他引:1  
对狭义干蘑属(Xerulas.str.)的范围进行了重新界定,该属仅包括模式种干蘑(X.pudens)及其周围的几个种。属的特征是担子果金钱菌状,有假根;菌盖及菌柄表面干燥,被有黄色至褐色直立、披针形的刚毛;菌褶边缘无不育带;子实层有近梭形的小担子。这些特征可以将干蘑属的物种从干蘑属-小奥德蘑属复合群中分开。现知干蘑属包含六种,本文提供了这些种的检索表,并对各种进行了描述、图示或讨论。其中,硬毛干蘑(X.strigosa)是一新种,它与干蘑(X.pudens)和中华干蘑(X.sinopudens)相似,但与干蘑不同在于其担孢子较长,锁状联合稀少,侧生囊状体顶端壁薄;与中华干蘑的区别在于其侧生囊状体壁厚,顶端有头状至近头状膨大并覆盖有结晶,担孢子宽椭圆形至椭圆形。中华干蘑和小刺干蘑(X.setulosa)分别为我国和哥斯达黎加的新记录种。干蘑属虽然广布北半球,但未见东亚-美洲或欧亚广布的物种分布类型。  相似文献   

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