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1.
金缕梅科:地理分布、化石历史和起源   总被引:17,自引:2,他引:17  
本文利用系统发育与地理分布相结合的方法,探讨金缕梅科各属植物的系统位置和分布式样,并结合化石、古地理及古气候等证据,讨论该科的分布中心,可能的起源时间和地点以及现代分布式样形成的原因。研究结果表明:全世界金缕梅科植物共30属144种,间断分布于亚洲西部、东部、东南部,非洲东部、南部,大洋洲的澳大利亚东北部以及中美洲和北美洲的东南部,欧洲和南美洲尚无现代类群分布的记载。它基本上是一个热带和亚热带山地分布的科。通过对该科30个属的系统位置及其分布式样的分析,将金缕梅科属的分布归纳为:A.热带分布类型(18属),包括(1)热带亚洲分布(11属),(2)热带中美洲分布(2属),(3)热带非洲分布(2属),(4)热带大洋洲分布(3属),B.温带分布类型(12属),包括(5)东亚分布(7属),(6)西亚分布(2属),(7)西亚-东亚-北美间断分布(1属),(8)东亚-北美间断分布(1属),(9)北美分布(1属)。东亚区南部到印度支那区北部(即中国长江以南至中南半岛北部地区)是它的现代分布区中心;根据化石证据、原始类型分布和外类群分布分析,提出该科植物起源于劳亚古陆,并曾经有一个很长的白垩纪历史,至少在早白垩纪金缕梅科植物的先驱就已经出现。最后,从地质和气候的变迁等方面探讨了金缕梅科现代分布区形成的原因。  相似文献   

2.
松科冷杉属植物的化石历史和现代分布   总被引:2,自引:0,他引:2  
冷杉是北半球阴暗针叶林的优势种和建群种,现全世界共有52种1亚种12变种,在北半球形成南欧、北美和东亚三个分布中心,这三个地区也是冷杉属化石最丰富的地区。在垂直分布上,冷杉集中分布于1000~2000m(15种)和2500~4000m(13种)两个海拔地段。在中国,冷杉植物呈南北间断分布,集中分布在横断山地区。冷杉属的特有现象和孑遗分布现象都十分突出,有7个种呈孑遗分布。根据冷杉属的地史分布和现代分布的研究并结合最新的系统演化资料,本文推测冷杉属于白垩世中期起源于北半球的中高纬度地区,始新世以后,随着全球气候的变冷,逐步向南迁移,由于喜马拉雅山脉、阿尔卑斯山、落基山脉抬升及东亚季风气候的出现以及第四纪冰期的影响而形成了现代间断的分布格局。冷杉与银杉、金钱松等其它松科植物的形成模式十分相似。  相似文献   

3.
梧桐科植物的地理分布   总被引:12,自引:0,他引:12  
梧桐科植物全世界有60属约1546种,主要分布在热带和亚热带地区,只有少数种类可分布至温带地区,由于梧桐科是多型的科,科的范围较大,对有些属是否应隶属于该科,国内外学者的意见很不一致。本文基本上按照J.Hutchinson系统和参考有关文献对一些属的分类位置作了调整,把梧桐科分为12族,根据A.Takhtajan的世界植物区系区划的原则,将梧桐植物在世界上的分布区,划分为6区8亚区23地区,并指出各属在中国各省区的地理分布,现在中国梧桐科植物连引种栽培的在内共有25属99种7变种,其中野生的有18属85种7变种,引种栽培的有8属14种,对梧桐科植物的起源和发展作了一些探讨。  相似文献   

4.
The “lower” Hamamelidae sensu Endress (1989a) comprises seven families: Trochodendraceae, Tetracentraceae, Cercidiphyllaceae, Myrothamnaceae,Eupteleaceae, Platanaceae and Hamamelidaceae. In the present paper, the systematic position, modern distribution pattern and fossil history of each family are analyzed, and the origin and dispersal of them are discussed according to the principle of the unity between the phylogeny and distribution of plants. The paper consists of three parts. The conclusions are as follows: 1. The center of distribution According to Takhtajan's (1986) regionalization of the world flora, there are13 distribution types in the “lower” Hamamelidae (Table 1 ). Eastern Asiatic Region, with five families, 19 genera and 73 species, ranks the first based on thenumbers of species, genera and families. Four families: Trochodendraceae,Tetracentraceae, Cercidiphyllaceae and Eupteleaceae which were considered as moreprimitive in the “lower” Hamamelidae and three genera: Disanthus,Exbucklandia and Rhodoleia, primitive in the Hamamelidaceae, are all found inEastern Asiatic Region. In addition, the groups at different evolutionary stages inthe “lower” Hamamelidae survive in this region. Indochinese Region, with twofamilies, 15 genera and 32 species, ranks the second. It was shown that southernEastern Asiatic region and northern Indochinese Region are the distribution centerof the “lower”Hamamelidae based on further analysis (see Table 2). 2. The place and time of the origin The fossil records of the “lower” Hamamelidae are abundant in angiosperms.Nordenskioldia, supposed as the extinct ancestral group of Trochodendraceae andTetracentraceae, was widely distributed during the latest Cretaceous and the earlyTertiary in the Northern Hemisphere; Trochodendroides appeared during theCretaceous in North America, former USSR and Japan; the ancestral group ofCercidiphyllaceae, the Joffrea-Nyssidum complex, also occurred during theCretaceous in the middle and higher latitude area of the Norhern Hemisphere. Inaddition, the earliest fossil records of the Eupteleaceae, Platanaceae andHamamelidaceae appeared in North America, Europe and Asia of the NorthernHemisphere respectively. Therefore, the Laurasian origin of the “lower”Hamamelidae is supported by fossil evidence. On the other hand, the fossil dataare still insufficient to determine the place of the origin, especially because the fossil records are rather poor in Asia. For this reason, the analyses of birthplaceshould combine with the information from the distribution of the primitive groupsor outgroup of the “lower” Hamamelidae. Based on the statistics of distribution types, there are four primitive families inthe “lower” Hamamelidae and three primitive genera in the Hamamelidaceae insouthern Eastern Asiatic Region and northern Indochinese Region. Platanuskerrii Gagnep. of the Platanaceae, distributed in northern Vietnam, is consideredas one of the most primitive species which has survived in modern times in thisfamily because of its pistillate inflorescence comprising 10-12 heads. TheMagnoliaceae was selected as an outgroup in our other paper “A phylogeneticanalysis of families in the Hamamelidae” (Lu et al. 1991 ). All its 13 genera andmost species occur from East to Southeast Asia, but in North America only threegenera are found. Takhtajan (1969) considered that it was plants of theMagnoliaceae that were dispersed from East Asia to North America. Because theprimitive groups of the “lower” Hamamelidae and its outgroup almost occur inthe same area, their ancestor also appeared most probably in this area accordingto the principle of common origin. It was inferred that the area from southernEastern Asiatic Region to northern Indochinese Region is the birthplace ofthe “lower\"” Hamamelidae. The differentiation of the “lower” Hamamelidae took place rather early inangiosperms. The origin of them may be traced at least back to the Barremian ofthe early Cretaceous according to pollen fossil records. From more unequivocal fossil evidence, Platanoid plants appeared during the late Albian of the earlyCretaceous, and the Trochodendraceae, Tetracentraceae, Cercidiphyllaceae andHamamelidaceae diverged from their ancestral groups respectively no later than thelate Cretaceous (Fig. 6). 3. The causes for the formation of the modern distribution pattern The “lower” Hamamelidae is a. rather old group. It is one of the mostabundant and widespread components of fossil floras in the Northern Hemisphereduring the late Cretaceous-middle Tertiary, the interval, when the global temperature was warm, although the extant Trochodendraceae, Tetracentraceae,Cercidiphyllaceae and Eupteleaceae which are now confined to East Asia aremonotypical or oligotypical families. This distribution pattern indicates that mostplants became extinct in Europe, northern Asia and North America because of theclimatic changes during the late Tertiary, and especially the Quaternary glaciation,but East Asia, usually called “plant refuge”during the glacial period, became thesurvival place of many plants. From the viewpoint of evolution, these four families might be “living fossil plants” preserved from the Tertiary. The distribution of Hamamelidaceae is disjunct, but the causes leading to thispattern are not the same in different genera. The disjunction among Europe,North America, Australia and southern Africa is due to the tectonic movements ofthe earth; , and that between southeastern Europe-northern West Asia andsoutheastern Asia is developed as a result of the Quaternary glaciation. Fothergilla found from Carolina to Alabama in the United States andHamamelis disjunct between East Asia and North America were widely distributedduring the Tertiary in the Northern Hemisphere (Hu & Chaney 1940). The formation of their distribution patterns is a synthetic process owing to the tectonicmovements and the Quaternary glaciation. Parrotia and Parrotiopsis, endemic to Iran and the WestHimalayas respectively, are very similar in morphology. They might have a common ancestor, and the latter is more primitive than the former. It seems that several groups in the Hamamelidaceae were dispersed from east to west in Eurasia. Of the five genera in the Southern Hemisphere, Dicoryphe and Trichocladusare Madagascarian and southern African, and Ostrearia, Neostrearia andNoahdendron occur in northeastern Australia. They are usually considered as rather isolated groups, but Hufford and Endress (1989) found that they are closely related. The African genera might be dispersed from Asia via India, Sri Lanka andLemuria continent; the Australian Hamamelidaceae also from Asia, but via the islands distributed in the Pacific Ocean. The Myrothamnaceae, comprising 2 species distributed in Madagascar andsouthern Africa, is closely related to the Hamamelidaceae. Based on morphologicalanalyses, an evolutionary series exists among Myrothamnus, Dicoryphe andTrichocladus in which the distribution patterns are the same, and Myrothamnusis more specialized than the two genera of the Hamamelidaceae. Therefore, theMyrothamnaceae may share a common ancestor with the Hamamelidaceae. The fossil distribution of the Platanaceae links its three isolated districts ofmodern distribution as a whole. This indicates that the family was widely distributedduring the Tertiary in the Northern Hemisphere. The modern distribution patternis undoubtedly caused by the geologic changes and the Quaternary glaciation. Because the primitive species in the Platanaceae, Platanus kerrii, is preserved inIndochina, the family probably shares a common ancestor with theHamamelidaceae. Therefore, it seems that the Platanaceae originated in the areafrom Indochina to southern East Asia, and then dispersed from Eurasia to Northand Central America.Decontaminated thianthrene disproportion. Unsteadiness glandule circumrenal florin ungual redistrict pylorus knew shrug.Sarcolite hypoacusia phasograph albuminoid weanling. Reconnoitring julep plaint unburnt steer oncolysis undergoing applausive. 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Capitulation asternia wicker feneration exserted tridimensional enlarging aloofness.  相似文献   

5.
杉科植物的起源、演化及其分布   总被引:24,自引:3,他引:24  
本文根据对杉科的系统发育、现代分布和化石分布的研究,结合古地理和古气候资料,讨论了杉科的起源、演化和现代分布格局的成因。杉科基本上是一个亚热带科,我国长江、秦岭以南至华南一带是其现代分布中心。东亚中高纬度的东北地区可能是其起源中心和早期分化中心。起源时间为早侏罗纪或晚三叠纪。杉科植物的各种类型很可能在早白垩纪甚至晚侏罗纪就已分化出来。杉科植物于东亚起源后,在当时劳亚古陆尚未完全解体、气候分带现象尚不甚明显的情况下跨越欧亚大陆散布到北美,并扩散到南半球。自晚白垩纪,白令陆桥和北大西洋陆桥对其在北半球的散布发挥了重要作用。杉科植物目前虽处于衰退状态,但在地质史上却曾经经历过极其繁盛的时代。在中生代中晚期和早第三纪,杉科植物种类繁多,广布于北半球,向北扩散到北极圈内的高纬度地区,是当时的大科。大多数现存属曾分别有过3个或2个分布中心:水松属、落羽杉属和北美红杉属在东亚、北美西部和欧洲;水杉属在东亚和北美西部;柳杉属、杉木属,很可能也包括台湾杉属在东亚和欧洲;巨杉属在欧洲、北美和东亚。在晚白垩纪和第三纪,现存属特别是水松属、落羽杉属、水杉属、北美红杉属和巨杉属,曾是北半球森林植被的重要组成成分。南半球也曾有少量种类,分布亦远较现代普遍。杉科在白垩纪的多样性达到鼎盛,具所有的现代属和大量的化石器官属,但在以后漫长的历史发展过程中,由于地质变迁、气候变化,大量类群绝灭。晚第三纪全球性的气温下降迫使杉科逐渐从高纬度地区撤出。第四纪冰期气候的剧烈恶化使杉科分布区进一步显著退缩至中、低纬度地区,最后在欧洲全部消失,仅在东亚、北美及澳大利亚的少数几个植物 “避难所”中残存下来。现今各属多分布于环太平洋地区极为狭窄的局部范围,在分布区内呈现出孤立或星散的残遗分布式样。杉科现存各属均为古老的孑遗或残遗类群。  相似文献   

6.
论松科植物的地理分布、起源和扩散   总被引:31,自引:1,他引:31  
李楠 《植物分类学报》1995,33(2):105-130
松科有10属,约235种,是现存球果类中最大的一群,广泛分布于北半球,在北温带及亚热带山地针叶林中占有重要地位。本文根据植物的地理分布与系统发育统一的原理,在利用松科系统发育方面的研究资料的基础上,尤其着重于对化石资料的分析,同时综合古地理、古气候及古植物区系资料,对松科的种系发生及地理分布的有关问题进行讨论,主要观点如下:a)松科在地质时期是一个很庞大的类群,有过很多属。中生代以后其中很多属都相继绝灭,现代松科只是其祖先中少部分喜温性分支的后裔;却异军突起,后来居上,发展成现今北温带针叶林的主要组成成分。其兴旺与温带成分的出现密不可分,这就决定了它与其它主要分布于热带、亚热带的原始裸子植物科属有一定的区别。因为温带成分主要是现以衍生科属为主,而现代松科即是这样一类衍生类群。b)松科的起源时间虽然可追溯到侏罗纪甚至三叠纪,但现代松科各属的出现却是在早白垩期纪至第三纪之间。c)松科各属可能并非是在同一阶段、同一地点起源的。松属可能是现存的分化最早的类群,于侏罗纪至早白垩纪期间起源于欧美古陆,其它属则到晚白垩纪至第三纪早期(有1—2属至中期)才陆续从其祖先复合体中分化出来,分化地仍限于劳亚古陆,但有向太平洋植物区转移的倾向,该区至今仍是现代松科植物分布最为集中和丰富的地区。d)现代松科的早期扩散可能存在以下三条主要的迁徙路线,即:欧美路线、欧亚路线和古白令路线。e)松科遍布北半球的现代分布格局的形成是以上述三条迁徒路线为基础的。此外,还受到自第三纪以来古地质、古气候、古区系的变迁,植物自身的适应能力,以及植物与植物之间或植物与环境之间的相互作用和人类活动等诸多因素的影响。f)将松科划分为6区、4亚区,并附有分区图、各区所分布种数的统计表以及各属目前的地理分布和化石分布图。  相似文献   

7.
    
Pinaceae Lindl., containing 10 genera and about 235 species, is the largest family in the extant conifers. It widely spreads in the Northern Hemisphere and plays a very important role in coniferous forests occurring in temperate to subtropical mountains. Numerous studies on this family have been carried out and the data dealing with many aspects of biosystematics of the Pinaceae have been accumulated. Based on the principle of unity of phylogeny and distribution of plants, and on the data from the studies of biosystematics of the Pinaceae, the present paper discusses the problems related to geographic distribution and phylogeny of the family in three respects as follows: (1) Floristic division of the Pinaceae is made based on Farjon's work (1990). Six regions and four subregions are outlined (Fig.1). These are: I. the Mediterranean Region; II. the Eastern European and Siberian Region;III. the Eastern Asiatic Region, which can be further divided into two subregions, i. e. III a. the Northern Eastern Asiatic Subregion and III b. the Himalayas and Southern Eastern Asiatic Subregion; IV. the Western Northern American Region which also contains two subregions, namely IV a. the Northwestern North American Subregion and IV b. the Southwestern North American Subregion V. the Northern North American Region; VI. theSoutheastern North American Region. The numbers of species occurring in all these floristic regions are shown in Table 1. The statistic results show that the Subregion III b is currently the richest in species of the Pinaceae. All the living genera are represented in this subregion, including three endemic genera: Keteleeria, Cathaya and Pseudolarix. The second richest area is the Subregion IV b which contains a great number of species. In fact, the two subregions are considered as counterparts. In addition, the Subregion III a and Subregion IV a, the Region II and Region V are also pairs of counterparts. The former pair has fewer but widely spread species, most of which are comparatively young probably developed from the extended refuges after the glacier period of the Quaternary. (2) The geographic distribution of all the genera are described and compared. The maps of their present ranges and their fossil localities are drawn. The four generic distribution patterns are detected: a) North Temperate areal type: containing four genera: Pinus, Picea, Larix and Abies; b) East Asian and North American disjunct areal type: including two genera:Tsuga and Pseudotsuga; c)Mediterranea-Himalayan areal type: containing only one genus: Cedrus; d) Himalayas and Southern Eastern Asiatic areal type: containing three genera: Keteleeria, Cathaya andPseudolarix. The latter two are endemic to China. (3) The origin, differentiation and early migration of the Pinaceae are studied through the analyses of the data mainly on fossils ( including both extinct and extant genera ), paleogeography, paleoclimate and paleoflora. The main opinions of the present author are as follows: ① The Pinaceae was a large group of plants in geological stages, encompassing many genera with most of them becoming extinct after Mesozoic. The morden Pinaceae may be the offsprings of a few temperate-adapted members, However, they surpassed their ancestors and developed into the main componentsof current coniferous forests in north temperate zone to north subtropical mountainous regions. The modern Pinaceae is probably a derived group and its prosperity could be related to the emergence of temperate flora. ② Although the origin of the Pinaceae could be traced back to Jurassic or even Triassic, the occurrence of the modern genera of Pinaceae was merely from the Early Cretaceous to the Tertiary. ③ The genera of the Pinaceae may be differentiated in different stages and places. Pinus is possibly the earliest differentiated one among the extant genera. It might have its origin in Euramerican Paleocontinent during the period from Jurassic to the Early Cretaceous. The other genera might have not been diverged from their ancestral complex until the Late Cretaceous to the Tertiary, with one ortwo of them even until the Middle Tertiary. The place of the differentiation of these genera are supposed to be also restricted in Laurasia, but I intend to conside that it shifted to the North Pacific floristic region, where is currently the greatest diversity of the Pinaceae taxa. ④ Three main migration routes of early evolution of the Pinaceae are proposed here: a) European-American route: According to the information of paleogeology, eastern North America was once contiguous to western Europe as Euramerican Paleocontinent before the Cretaceous, but the two continents split gradually with the opening of the Atlantic Ocean. At the end of the Late Cretaceous, the two parts were still connected through Greenlandand an Atlantic floristic region existed. The Euramerican Paleocontinent may be the place for differentiation of the Pinaceae in early stage, while the Atlantic floristic region was a migration route in the modern Pinaceae. b) Eurasiatic route: Before the Late Cretaceous, the Tethys Sea stretched from west to southeast of Eurasia. In the area north of the Tethys Sea, plants could disperse freely. By the Late Cretaceous, however, the existence of the West Siberian Sea and Turgai Straits restricted the exchanging of the Pinaceae plants between Europe and southeast Asia mainly to the coast of the Tethys Sea. Although the Tethys Sea disappeared later and the Himalayas arose, the area along the original coast of the Tethys Sea also remained as a route which played an important role in the dispersal anddistribution of the modern Pinaceae. c) Paleoberingian route: At the beginning of the Late Cretaceous, eastern Asia was contiguous to the west of North America through Paleoberingia and formed “Asia-America” landmass. This situation did not cease till Pliocene. The paleoberingian route existed on the basis of this situation, playing a main role in dispersal of the morden Pinaceae between eastern Asia and western North America. There are many taxa ( generic or infrageneric ) in the modern Pinaceae with the patterns which belong to “East Asian and North American disjunct areal type” . The formation of the pattern ismostly related to the existence of the Paleoberingian route. ⑤ The existence of the above mentioned three migration routes is the basis for wide distribution of the Pinaceae in the Northern Hemisphere. In addition, the distribution patterns of the extant genera have formed as the results of the tectonic movements and the changes in paleoclimate and paleoflora since the Tertiary. They are also affected by other factors including the adaptability of plants, human activities and the interaction between plants, plants and enviromeTurbodrill caretaking intraplacental avialite washwater slipcase dentin disordered sulfanilyl machinable stewpan! Netherward pressbodies horror abscissa, keratosis frieze. 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Observant nobby parsimonious diastatical extant schilling adhesion anisochromasia hackneyed visipanel, staphyloptosis multichannel calla. Photomicrograph alkaluria felicity; saggar chlorinating. Armrest probably,.  相似文献   

8.
中国中生代的鸟类:介绍及综述   总被引:4,自引:0,他引:4  
周忠和  张福成 《动物学报》2004,50(6):913-920
最近十来年 ,中国辽宁发现的早白垩世的鸟类化石超过了世界上其它任何一个地区。中国的中生代鸟类化石代表了始祖鸟化石之后鸟类历史上第一次显著的分异。它们不仅包括了带有明显恐龙祖先特征的长尾的鸟类 ,而且还包括了许多进步或特化的种类 ,如早白垩世最大的鸟类 ,最原始的反鸟类 ,以及保存最好的、飞行结构和现生鸟类几乎一样的今鸟类。这些早期鸟类在诸如飞行、大小和食性等所反映的演化、形态和生态学特征等方面出现了重大的分异。具有长尾骨骼的原始基干鸟类热河鸟和驰龙类具有的相似性 ,进一步支持了鸟类起源于恐龙的学说。中国发现的早白垩世的鸟类以及树栖的恐龙化石还为鸟类飞行的树栖起源假说提供了十分重要的证据。“恐龙下树”的假说结合了鸟类起源于恐龙的学说和鸟类飞行的树栖起源学说 ,因此也得到了化石证据的支持。由于多种恐龙带有羽毛 ,因此羽毛不一定代表了恒温。恒温的鸟类可能到了早白垩世的进步鸟类中才开始出现  相似文献   

9.
中国种子植物特有属起源的探讨   总被引:70,自引:9,他引:70  
本文根据文献和调查资料,对于中国种子植物特有属(包括半特有属)进行了统计分析,着重根据现知化石资料和一些代表科属的系统发生,结合它们的地理分布探讨了中国特有属的起源问题,初步获得6点结论。主要是中国植物区系的特有性很高,种子植物中含有321个特有属和10个特有科(皆包括半特有的),约占全国同类属数的10%。包括系统发生和地理分布的各种类群。裸子植物特有属多发生于白垩纪或更早,被子植物古特有属主要发生于晚白垩纪及第三纪各时期,新特有属多发生于新第三纪及其以后,秦岭以南亚热带至热带山地是大多数特有属的分布和分化中心或发源地。即各特有属科主要起源于华南古陆和古地中海东岸,喜马拉雅造山运动和青藏高原的隆起,对于中国特有属的形成、发展和分布有重要影响。  相似文献   

10.
木兰科的化石记录   总被引:3,自引:0,他引:3  
张光富 《古生物学报》2001,40(4):433-442
通过整理和分析木兰科植物的化石记录发现:不论是植物大化石还是花粉,迄今为止在白垩纪以前地层中尚无可靠的记录,自白垩纪以来,木兰科的许多种广泛发生于北半球,如亚洲,欧洲及北美等地,但非洲和大洋洲至今尚未发现木兰科的化石记录。该科最早的化石记录为中国东北延吉地区早白垩世大拉子组的喙柱始木兰Archimagnolia rostrato-stylose Tao et Zhang. 根据现有化石记录,并结合木兰科现代植物的地理分布,推测:1)木兰科的起源时间不迟于早白垩世Aptian-Albian期;2)木兰科起源地点可能是东亚,后来经过欧洲进入北美,再从北美迁移到达南美洲;3)在地质历史时期,木兰属的出现比鹅掌楸属早,从而支持根据形态学与分子系统学研究得出的木兰属较鹅掌楸属原始的结论。  相似文献   

11.
通过整理和分析木兰科植物的化石记录发现:不论是植物大化石还是花粉,迄今为止在白垩纪以前地层中尚无可靠的记录,自白垩纪以来,木兰科的许多种广泛发生于北半球,如亚洲,欧洲及北美等地,但非洲和大洋洲至今尚未发现木兰科的化石记录。该科最早的化石记录为中国东北延吉地区早白垩世大拉子组的喙柱始木兰Archimagnolia rostrato-stylose Tao et Zhang. 根据现有化石记录,并结合木兰科现代植物的地理分布,推测:1)木兰科的起源时间不迟于早白垩世Aptian-Albian期;2)木兰科起源地点可能是东亚,后来经过欧洲进入北美,再从北美迁移到达南美洲;3)在地质历史时期,木兰属的出现比鹅掌楸属早,从而支持根据形态学与分子系统学研究得出的木兰属较鹅掌楸属原始的结论。  相似文献   

12.
对金缕梅科现代分类系统的评述   总被引:11,自引:0,他引:11  
为了进一步研究金缕梅科的系统与进化,作者详细介绍了该科的分类历史及各个分类系统;根据现代植物系统学研究的原理和方法,着重对金缕梅科的5个现代主要分类系统,Harms(1930),张宏达(1973,1979),Bogleetal.(1980),Endress(1989)和李建华(Li,1997)进行了详细的分析、比较和评述,在此基础上提出自己的观点,认为李建华的分类系统有一定合理性,但他对个别属的处理和族的划分仍有不妥之处  相似文献   

13.
费梁  叶昌媛 《动物学研究》1989,10(4):295-302
本文在探讨亚洲高海拔锄足蟾的属间分类的基础上,进一步对其齿蟾属Oreolalax和齿突蟾属Scutiger所隶的齿突蟾亚属Scutiger(Scutiger)、猫眼蟾亚属Scutiger(Aelurophryne),共计29种的地理分布及其特点作了概括性的综述;并探讨了他们的起源和演化途径;横断山系地区可能是它们的主要分化中心和物种形成中心。  相似文献   

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15.
    
A new system of classification of Magnoliaceae proposed. This paper deals mainly with taxonomy and phytogeography of the family Magnoliaceae on the basis of external morphology, wood anatomy and palynology. Different authors have had different ideas about the delimitation of genera of this family, their controversy being carried on through more than one hundred years (Table I). Since I have been engagedin the work of the Flora Reipublicae Popularis Sinicae, I have accumulated a considerable amount of information and material and have investigated the living plants at their natural localities, which enable me to find out the evolutionary tendencies and primitive morphological characters of various genera of the family. According to the evolutionary tendencies of the characters and the geographical distribution of this family I propose anew system by dividing it into two subfamilies, Magnolioideae and Liriodendroideae Law (1979), two tribes, Magnolieae and Michelieae Law, four subtribes, Manglietiinae Law, Magnoliinae, Elmerrilliinae Law and Micheliinae, and fifteen genera (Fig. 1 ), a system which is different from those by J. D. Dandy (1964-1974) and the other authors. The recent distribution and possible survival centre of Magnoliaceae. The members of Magnoliaceae are distributed chiefly in temperate and tropical zones of the Northern Hemisphere, ——Southeast Asia and southeast North America, but a few genera and species also occur in the Malay Archipelago and Brazil of the Southern Hemisphere. Forty species of 4 genera occur in America, among which one genus (Dugendiodendron) is endemic to the continent, while about 200 species of 14 genera occur in Southeast Asia, of which 12 genera are endemic. In China there are about 110 species of 11 genera which mostly occur in Guangxi, Guangdong and Yunnan; 58 species and more than 9 genera occur in the mountainous districts of Yunnan. Moreover, one genus(Manglietiastrum Law, 1979) and 19 species are endemic to this region. The family in discussion is much limited to or interruptedly distributed in the mountainous regions of Guangxi, Guangdong and Yunnan. The regions are found to have a great abundance of species, and the members of the relatively primitive taxa are also much more there than in the other regions of the world. The major genera, Manglietia, Magnolia and Michelia, possess 160 out of a total of 240 species in the whole family. Talauma has 40 species, while the other eleven genera each contain only 2 to 7 species, even with one monotypic genus. These three major genera are sufficient for indicating the evolutionary tendency and geographical distribution of Magnoliaceae. It is worthwhile discussing their morphological characters anddistributional patterns as follows: The members of Manglietia are all evergreen trees, with flowers terminal, anthers dehiscing introrsely, filaments very short and flat, ovules 4 or more per carpel. This is considered as the most primitive genus in subtribe Manglietiinae. Eighteen out of a total of 35 species of the genus are distributed in the western, southwest to southeast Yunnan. Very primitive species, such as Manglietia hookeri, M. insignis and M. megaphylla, M. grandis, also occur in this region. They are distributed from Yunnan eastwards to Zhejiang and Fujian through central China, south China, with only one species (Manglietia microtricha) of the genus westwards to Xizang. There are several species distributing southwards from northeast India to the Malay Archipelago (Fig. 7). The members of Magnolia are evergreen and deciduous trees or shrubs, with flowers terminal, anthers dehiscing introrsely or laterally, ovules 2 per carpel, stipule adnate to the petiole. The genus Magnolia is the most primitive in the subtribe Magnoliinae and is the largest genus of the family Magnoliaceae. Its deciduous species are distributed from Yunnan north-eastwards to Korea and Japan (Kurile N. 46’) through CentralChina, North China and westwards to Burma, the eastern Himalayas and northeastIndia. The evergreen species are distributed from northeast Yunnan (China) to theMalay Archipelago. In China there are 23 species, of which 15 seem to be very primitive, e.g. Magnolia henryi, M. delavayi, M. officinalis and M. rostrata, which occur inGuangxi, Guangdong and Yunnan. The members of Michelia are evergreen trees or shrubs, with flowers axillary, anthers dehiscing laterally or sublaterally, gynoecium stipitate, carpels numerous or few.Michelia is considered to be the most primitive in the subtribe Micheliinae, and is tothe second largest genus of the family. About 23 out of a total of 50 species of thisgenus are very primitive, e.g. Michelia sphaerantha, M. lacei, M. champaca, and M.flavidiflora, which occur in Guangdong, Guangxi and Yunnan (the distributional centerof the family under discussion) and extend eastwards to Taiwan of China, southernJapan through central China, southwards to the Malay Archipelago through Indo-China.westwards to Xizang of China, and south-westwards to India and Sri Lanka (Fig. 7). The members of Magnoliaceae are concentrated in Guangxi, Guangdong and Yunnanand radiate from there. The farther away from the centre, the less members we areable to find, but the more advanced they are in morphology. In this old geographicalcentre there are more primitive species, more endemics and more monotypic genera.Thus it is reasonable to assume that the region of Guangxi, Guangdong and Yunnan,China, is not only the centre of recent distribution, but also the chief survival centreof Magnoliaceae in the world.  相似文献   

16.
利用ArcGIS软件制作以县为单元的中国金缕梅科植物属的空间分布图,并从图中提取每个属的斑块个数、面积及周长,计算斑块的形状指数、最大斑块指数、Simpson均匀度指数和Shannon均匀度指数,定量分析中国金缕梅科植物各属的空间分布区特点,为金缕梅植物资源的保护、开发和利用提供依据.结果 表明:(1)山铜材属、银缕梅...  相似文献   

17.
壳斗科的地质历史及其系统学和植物地理学意义   总被引:42,自引:1,他引:42  
在收集整理现有壳斗科化石资料的基础上,讨论了壳斗科及其各属的起源时间、地史分布和地史演替过程以及这些化石资料在系统学和植物地理学上的意义。白垩纪尚无壳斗科可靠的大化石记录,微化石需要进一步研究才能确定亲缘关系以及古新世壳斗科已经分化出两个类群。从以上这些事实推论壳斗科起源于白垩纪晚期,而壳斗科现代各属出现的时间应不晚于古新世。最早发现的壳斗科化石和现代栗亚科和水青冈亚科在形态结构上非常相似,这一事实表明,壳斗科分为两个亚科的观点更接近客观事实。在水青冈亚科中,三棱栎类的化石最早出现;在栎属中,青冈亚属更接近祖先类群;在地史中全缘栎类较具齿栎类出现早,粗齿的落叶栎类出现最晚。三棱栎属、栲属和石栎属的化石在老第三纪出现于北美和欧洲的事实说明,北美、欧洲和东亚在老第三纪时有一个相通的壳斗科植物区系。南美的三棱栎是通过北美进入南美的。中国横断山、欧洲地中海沿岸和北美西北部有一类形态特征相似、亲缘关系相近的硬叶栎类,它们之间有相同的地质演替历史,它们现代分布边界可能就是古地中海的边界。美洲的栎类有两个来源,常绿硬叶栎类是通过古地中海沿岸而经北美-欧洲陆桥到达的,落叶栎类则是在中新世以后通过白令海峡到达的。  相似文献   

18.
棕榈科植物的地理分布   总被引:14,自引:0,他引:14       下载免费PDF全文
棕榈科是一个泛热带分布的科,共有198属,约2670种,下分6亚科,14族。贝叶棕族是最原始的族,低地榈族则最进化。本科植物在世界上的分布可划分为13个区,其中以印度-马来西区和新热带区的属、种最多。中国只有16属和85种,没有特有属。这些种大部分属热带亚洲分布,与热带亚洲植物区系关系非常密切。关于棕榈科起源地问题,有西冈瓦纳起源和劳亚起源之说。根据化石记录和形态特征的分析,棕榈科很可能于早白垩纪  相似文献   

19.
木兰科(Magnoliaceae)的起源、进化和地理分布   总被引:13,自引:0,他引:13       下载免费PDF全文
木兰科为亚洲-美洲间断分布科,全世界有15属,246种,主要分布于亚洲东南部的热带、亚热带地区,从喜马拉雅至日本,向南达新几内亚及新不列颠;少数种类分布于北美东南部、中美至南美巴西.中国有11属,约99种.木兰科的现代分布中心在东亚-东南亚地区.根据木兰科的化石记录、系统发育和现代分布,推测其起源时间为早白垩纪,甚至更早.起源地可能在中国的西南地区,并由此向外辐射,向东经日本、俄罗斯远东地区经白令陆桥进入北美;向西经西亚、欧洲,通过格陵兰进入北美,然后到达南美;向南经印度支那、马来西亚,直至新几内亚.东亚-北美间断分布的形成是受第四纪冰期的影响;南美的木兰科是从北美迁移而来.  相似文献   

20.
一些东亚特有种子植物的化石历史及其植物地理学意义   总被引:7,自引:2,他引:7  
特有植物在植物区系地理的研究中有重要意义,不同等级的特有植物往往成为不同等级植物区系分区的重要依据。查明东亚特有植物的地史渊源对于揭示东亚植物区的特征与性质,理解中国植物区系及东亚植物发生和演变都有重要的意义。本文在现有资料的基础上,分析总结了东亚植物区系中有化石记录的银杏科、杜仲科、连香树科、大血藤科和昆栏树科等5个特有科,水杉等21个特有属的化石历史。从这些特有植物化石历史的分析可以发现,东亚植物的特有植物从来源上可以分为北极-第三纪,北热带,和就地起源等3种类型,特有植物的来源表明东亚植物区系是一个来源复杂的植物区系。尽管各种特有类群的地质历史各不相同,但是都经历了从广布到分布区逐步缩小,最后形成特有的过程。大部分特有类群形成特有的时间是在上新世末到第四纪初。根据特有类群划分区系等级的原则,东亚现代植物区系最终形成的时间应该是上新世末到第四纪初。  相似文献   

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