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1.
槲栎叶复合群及其地史学和系统学意义   总被引:3,自引:0,他引:3  
根据槲栎叶复合群研究的最新成果订正了国产槲叶栎属 (Dryophyllum)的化石。通过对该属 9种化石的整理 ,将 Dryophyllum dewalquei、D.parvum、D.relongtanense、D.yunnanensis和 D.sp.等 5种分别归入 Berryophyllum dewalquei、B.parvum、B.relongtanense、B.yunnanensis和 B.sp.;将 D.fushunense归入 Castaneophyllum fushunense;将 D.nervosaum归入 Quercusnervosum;将 D.relongtanense的一部分归入Q.lantenoisii;D.subfalcatum尚不能确定归属 ,但可以肯定不属槲栎叶复合群。同时 ,还讨论了槲栎叶复合群的地史学意义。该复合群是原始壳斗科向现代壳斗科过渡的中间类群 ,壳斗科各现代属出现的时间不早于古新世  相似文献   

2.
禄丰古猿化石地点的植物叶化石   总被引:2,自引:0,他引:2  
1987年,在云南禄丰古猿化石地点D剖面第4层(薄层黑色炭质粘土与灰色细砂互层)发现植物叶部印痕化石,经鉴定属壳斗科绝灭的雷龙潭槲叶(Dryophyllum relongtanense Colani),该种植物常参与组成亚热带至暖温带的常绿阔叶林或常绿与落叶阔叶混交林。  相似文献   

3.
1987年,在云南禄丰古猿化石地点D剖面第4层(薄层黑色炭质粘土与灰色细砂互层)发现植物叶部印痕化石,经鉴定属壳斗科绝灭的雷龙潭檞叶(Dryophyllum relongtanense Colani),该种植物常参与组成亚热带至暖温带的常绿阔叶林或常绿与落叶阔叶混交林。  相似文献   

4.
The fossil history of the Fagaceae from China and its systematic and biogeographic implications are discussed based on revisionary studies of the fossil records. No creditable macrofossil record of the Fagaceae exists in the Cretaceous deposits and all the Cretaceous microfossil reports remain equivocal and require further study. The Paleocene fossils show the appearance and diversification of the two groups corresponding to the subfamilies Fagoideae and Castaneoideae sensu Nixon. By the Eocene, all modern genera had been present. The oldest fagaceous fossils represent subfamily Fagoideae with affinities to the extant genus Trigonobalanus. The leaf fossil genus Berryophyllum, with affinities to Quercus subg. Cyclobalanopsis, has been documented by the early Eocene and might have occurred earlier than other fossils assignable to Quercus. The appearance of evergreen sclerophyllous Ouercus with entire leaves might have occurred earlier than those with toothed leaves. Deciduous, urticoid-leaved oak fossils (Quercus subg. Quercus sect. Quercus) had not appeared until the Miocene. Fossil equivalents of Trigonobalanus, Castanopsis and Lithocarpus had occurred in Europe and North America by the early Tertiary, suggesting that continuous distributions were achieved via the northern hemisphere land bridges. Three groups of evergreen sclerophyllous oaks of apparent close phylogenetic relationships occurred in the Hengduan mountains, the Mediterranean area and northwestern North America. Their fossil forms have become dominant elements of those vegetation zones since the Miocene. A shared fossil history indicates a possible biogeographic boundary formed by the ancient Mediterranean. The evidence suggests that the oaks might arrive in North America during two distinct geologic periods: evergreen sclerophyllous entire-leaved oaks appeared by the Early Tertiary, whereas thedeciduous oaks with urticoid leaves appeared in the Late Tertiary.  相似文献   

5.
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   

6.
Fruits, catkins, and associated leaves of at least two extinct trigonobalanoid taxa have been discovered at an Oligocene fossil plant locality rich in fagaceous remains. These fossils exhibit a mosaic of fruit and pollen characters found in the two extant subfamilies Castaneoideae and Fagoideae of Fagaceae. Comparison with cladograms based on modern taxa suggests that these extinct taxa were similar to the ancestors of subfamily Fagoideae and may have been intermediate between Fagus and the modern trigonobalanoid genera. Pollen types isolated from the fossil staminate catkins provide unique character states that are transitional between modern pollen types in Fagaceae and are important in understanding the evolution of exine micromorphology within the family. This analysis provides a striking example of the use of character data from fossils to determine character-state adjacency prior to polarization of characters using outgroup comparison. Because of the mosaic nature of their character complexes, these fossils support monophyly in both the family Fagaceae and the subfamily Fagoideae. In addition, the occurrence of trigonobalanoid fossils in the Oligocene of North America has interesting biogeographic implications and provides insights into the nature of North American Fagaceae during the Tertiary.  相似文献   

7.
8.
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   

9.
Phylogenetic relationships were examined within the "higher" Hamamelididae using 21 species representing eight families and related outgroups. Chloroplast DNA sequences encoding the matK gene (/1 kilobase) provided 258 informative nucleotide sites. Phylogenetic analysis of this variation produced one most parsimonious tree supporting three monophyletic groups. In this tree, Nothofagus was basal to a well supported clade of remaining "higher" hamamelids, in which Fagaceae, including Fagus, were sister to a clade of core "higher" hamamelids that share wind-pollination, bicarpellate flowers, granular pollen walls, and reduced pollen apertures. Within the core "higher" hamamelids three subclades were resolved, Myricaceae, (Casuarina-(Ticodendron-(Betulaceae))), and (Rhoiptelea-Juglandaceae). Each subclade was well supported but relationships among them were not. The basal position of Nothofagus within the matK tree is consistent with the fossil record of "higher" hamamelids in which Nothofagus pollen appears earlier than microfossils with affinities to other modern "higher" hamamelids. This placement supports the exclusion of Nothofagus from Fagaceae and suggests two hypotheses for the origin of the cupule. The cupule may be ancestral within "higher" hamamelids and subsequently lost in core members of the clade or there may have been two independent origins. It is suggested that the three clades (1) Nothofagaceae, (2) Fagaceae, and (3) Juglandaceae, Rhoiptelea, Myricaceae, Casuarina, Ticodendron, and Betulaceae be considered at the ordinal level and that traditional orders, such as Fagales sensu Cronquist (Fagaceae, Nothofagaceae, and Betulaceae) be abandoned. Comparative analyses of matK sequences with previously published rbcL sequences demonstrate that for the taxa considered here matK sequences produced trees with greater phylogenetic resolution and a higher consistency index.  相似文献   

10.
Fossil evidence of Fagaceae from the Paleocene/Eocene boundary of western Tennessee is described and discussed. These fossils include a newly discovered pistillate inflorescence and dispersed fruits of subfamily Castaneoideae as well as a taxon that resembles modern trigonobalanoids (pistillate inflorescences and dispersed mature fruits). Fossil staminate catkins with fagaceous pollen, which we suggest may be conspecific with the trigonobalanoid infructescences, are also found at the locality. Two distinct types of fagaceous leaves are present at the locality. The reproductive structures are the oldest megafossils unequivocally assignable to Fagaceae and represent the oldest remains of subfamily Fagoideae and the oldest megafossil remains of Castaneoideae. In addition, the fossils provide insights into the chronology of diversification, biogeography, and phylogeny of Fagaceae. The trigonobalanoid remains may also provide insights into the timing and circumstances of the evolution of wind pollination in Fagaceae.  相似文献   

11.
Functional gene transfer from the plastid to the nucleus is rare among land plants despite evidence that DNA transfer to the nucleus is relatively frequent. During the course of sequencing plastid genomes from representative species from three rosid genera (Castanea, Prunus, Theobroma) and ongoing projects focusing on the Fagaceae and Passifloraceae, we identified putative losses of rpl22 in these two angiosperm families. We further characterized rpl22 from three species of Passiflora and one species of Quercus and identified sequences that likely represent pseudogenes. In Castanea and Quercus, both members of the Fagaceae, we identified a nuclear copy of rpl22, which consisted of two exons separated by an intron. Exon 1 encodes a transit peptide that likely targets the protein product back to the plastid and exon 2 encodes rpl22. We performed phylogenetic analyses of 97 taxa, including 93 angiosperms and four gymnosperm outgroups using alignments of 81 plastid genes to examine the phylogenetic distribution of rpl22 loss and transfer to the nucleus. Our results indicate that within rosids there have been independent transfers of rpl22 to the nucleus in Fabaceae and Fagaceae and a putative third transfer in Passiflora. The high level of sequence divergence between the transit peptides in Fabaceae and Fagaceae strongly suggest that these represent independent transfers. Furthermore, Blast searches did not identify the "donor" genes of the transit peptides, suggesting a de novo origin. We also performed phylogenetic analyses of rpl22 for 87 angiosperms and four gymnosperms, including nuclear-encoded copies for five species of Fabaceae and Fagaceae. The resulting trees indicated that the transfer of rpl22 to the nucleus does not predate the origin of angiosperms as suggested in an earlier study. Using previously published angiosperm divergence time estimates, we suggest that these transfers occurred approximately 56-58, 34-37, and 26-27 Ma for the Fabaceae, Fagaceae, and Passifloraceae, respectively.  相似文献   

12.
壳斗科化石是北半球新生代地层的优势分子,然而由于其属种众多,叶片属种间特异性不明显,该科叶片化石的鉴定是古植物学研究的难点之一。面对化石标本不完整的性状特征信息,如何剔除冗余特征,重点考虑具有鉴定意义的标本特征,就显得非常必要。本研究通过调研多种降维算法,考虑到植物特征编码及赋值的数值特性,选用主成分分析法,以壳斗科青冈亚属植物叶片为例,对可能在化石叶片上观察到的22个性状特征(变量)进行降维处理,挑选出对于壳斗科化石叶片分类鉴定起主要作用的10个性状特征,并将其应用于化石鉴定进行验证。结果表明,仅考虑经过主成分分析法压缩挑选的10个主要性状特征,仍然能够实现壳斗科化石植物的准确鉴定。主成分分析法应用于壳斗科性状特征的降维处理效果良好,剔除冗余特征对标本鉴定结果没有影响。  相似文献   

13.
西藏壳斗科订正   总被引:4,自引:0,他引:4  
在野外观察和前人工作的基础上,对西藏壳斗科植物进行了详细的订正,描述了1个新种,报道1个中国新记录种,4个西藏新记录种,归并11种和2变种,排除无标本记录的2种。确认西藏壳斗科植物共3属32种,2变种。  相似文献   

14.
Since their discovery, Neanderthals have been described as having a marked degree of anteroposterior curvature of the femoral shaft. Although initially believed to be pathological, subsequent discoveries of Neanderthal remains lead femoral curvature to be considered as a derived Neanderthal feature. A recent study on Neanderthals and middle and early Upper Palaeolithic modern humans found no differences in femoral curvature, but did not consider size-corrected curvature. Therefore, the objectives of this study were to use 3D morphometric landmark and semi-landmark analysis to quantify relative femoral curvature in Neanderthals, Upper Palaeolithic and recent modern humans, and to compare adult bone curvature as part of the overall femoral morphology among these populations.Comparisons among populations were made using geometric morphometrics (3D landmarks) and standard multivariate methods. Comparative material involved all available complete femora from Neanderthal and Upper Palaeolithic modern human, archaeological (Mesolithic, Neolithic, Medieval) and recent human populations representing a wide geographical and lifestyle range. There are significant differences in the anatomy of the femur between Neanderthals and modern humans. Neanderthals have more curved femora than modern humans. Early modern humans are most similar to recent modern humans in their anatomy. Femoral curvature is a good indicator of activity level and habitual loading of the lower limb, indicating higher activity levels in Neanderthals than modern humans. These differences contradict robusticity studies and the archaeological record, and would suggest that femoral morphology, and curvature in particular, in Neanderthals may not be explained by adult behavior alone and could be the result of genetic drift, natural selection or differences in behavior during ontogeny.  相似文献   

15.
论山毛榉科植物的系统发育   总被引:10,自引:2,他引:8  
本文运用分支分类学方法,对山毛榉科植物进行了系统发育的分析。山毛榉科作为单元发生群包括柯属、锥属、粟属、三棱栎属、水青冈属和栎属。桦木科和南山毛榉属被选择作为外类群。对大量的性状进行评估之后,选择了25对性状作为建立数据矩阵的基本资料。性状极化以外类群比较为主,同时也采用了化石证据和通行的形态演化的基本原则。数据矩阵由7个分类群、2个外类群和25个性状组成。采用最大同步法、演化极端结合法和综合分析法对该数据矩阵进行了分析。在得到的3个树状分支图中按照最简约的原则,选出演化长度最短的谱系分支图作为本文讨论山毛榉科属间的系统演化关系的基础。关于山毛榉科植物的系统发育,作者的观点如下:(A)现存的山毛榉科的6个属形成了4条平行进化的分支路线,它们分别被处理作4个亚科,即:栗亚科,三棱栎亚科,水青冈亚科和栎亚科;(B)平行进化是山毛榉科植物系统发育过程中的主要形式。生殖过程中的一些特征,如:果实第二年成熟,胚珠通常败育等,是影响山毛榉科植物属间基因交流的主要原因。在现存的山毛榉科植物中,柯属是最原始的类群。三棱栎属和锥属的起源也较早,而栗属、水青冈属和栎属是特化的类群。  相似文献   

16.
中国水青冈属 (壳斗科) 叶结构及分类学意义   总被引:1,自引:0,他引:1  
叶结构对壳斗科(Fagaceae)现存植物和化石的鉴定具有重要意义。通过对水青冈属5种植物叶结构特征进行细致的研究,结果发现水青冈属植物叶脉有羽状弓形脉、羽状半达缘脉两种类型;三级脉有波状对生贯穿、互生贯穿及混合贯穿三种类型;小脉缺失、简单无分支或一次分支;脉间区发育良好,网眼有三边形、四边形和五边形三种类型,排列规则;具齿种类叶齿由齿主脉和齿侧脉构成,齿侧脉环状。研究结果表明水青冈属二级脉与更高级脉序形成的结构稳定且存在种间差异,具重要分类学价值。基于水青冈属叶结构特征观察结果,本次研究编制了水青冈属植物的分种检索表;参照已有研究结果并结合重要外部形态学特征,编制了壳斗科相关类群分属检索表。  相似文献   

17.
The fagaceous genus Trigonobalanus as recently treated includes 3 species, two in Malaysia and Southeast Asia and a single species in Colombia, South America. Character analysis suggests that the genus as currently circumscribed is paraphyletic, without synapomorphies to unite the three species. Each of the three species is a morphologically distinct relict of a group that probably was ancestral to the modern genera Quercus and Fagus. Each of the three species also has at least one autapomorphy which is unique within Fagaceae. Analysis of cupule morphology in Fagaceae provides an interpretation of evolution in cupules which differs substantially from Forman's interpretation. We interpret trigonobalanoid cupules as indicative of an ancestral type of inflorescence within Fagaceae. This inflorescence type is a dichasial structure in which the outermost axes are cupular valves, but the degree of branching and subsequent number of fruits are variable. Following this model, a strict relationship exists between valve number and fruit number as seen in cupules of Trigonobalanus (valves = fruits + 1). Fossil evidence is consistent with our interpretation of the phylogenetic position of the trigonobalanoids. We propose to segregate the three species of Trigonobalanus as three monotypic genera; two of these require names which we provide here: Formanodendron and Colombobalanus.  相似文献   

18.
郑维艳  曾文豪  唐一思  石慰  曹坤芳 《生态学报》2018,38(24):8676-8687
以中国大陆北热带及亚热带地区优势科樟科、壳斗科植物为研究对象,利用专著发表大量的样方数据和物种分布数据,分析樟科、壳斗科与群落构建的关系、它们各大属的地理分布格局,探讨影响其分布的可能历史原因。结果表明:中国大陆北热带及亚热带地区森林乔木层优势科为樟科、壳斗科、山茶科、杜鹃花科。樟科、壳斗科物种丰富度均与其所在群落的物种丰富度呈现一定的正相关,樟科对群落构建的贡献较大。樟科、壳斗科植物种的空间多样性分布中心均出现在我国亚热带中部偏南地区。樟科的厚壳桂属、琼楠属以及壳斗科的锥属物种多样性分布中心主要在南亚热带及北热带区域,以广西、云南省份的南部为主。樟科的樟属、新木姜子属、润楠属、木姜子属及壳斗科的柯属、青冈属主要分布在我国大陆北热带及亚热带中部偏南的地区,其多样性分布中心与樟科、壳斗科科水平的物种多样性分布中心极为相似。樟科的山胡椒属、楠属、黄肉楠属,壳斗科的栎属主要分布在研究区域中部以西的地区。研究结果佐证物种的生态学特性以及生物地理学历史综合作用导致目前樟科和壳斗科植物的生物多样性分布格局。  相似文献   

19.
广西壳斗科植物发掘利用初探   总被引:2,自引:0,他引:2  
曹明  邓敏  张奠湘   《广西植物》2007,27(2):170-173
在较全面野外考察、调研的基础上,结合资料查询、查阅,对广西壳斗科植物的发掘和利用进行了初步探索研究。该文着重对广西壳斗科植物资源的地理分布状况、经济利用价值及潜力、利用现状和前景等方面进行了论述;并提出了合理开发利用广西壳斗科植物的建议。  相似文献   

20.
Summary From May 1986 to May 1989 surveys of airborne biological particles have been performed in the atmosphere of Cosenza, Italy with the aim of monitoring the presence of airborne pollen. The survey station is situated at Arcavacata of Rende, a hilly area 474 meters above sea level, 7 km north-west of the main town. The sampler (VPPS 2000) is located about 20 meters above ground level. The monitoring, performed in accordance with the criteria suggested by the Italian Association of Aerobiology (A.I.A.), enabled the identification of 26 different pollen types. The pollination graphics show: 1) a late winter period in which pollen from trees appears; 2) a spring period with a prevalence of Gramineae, Fagaceae, Oleaceae andParietaria pollen; 3) a late spring-summer period during which Fagaceae,Pinus and Compositae pollen grains are present; 4) a late summer-autumn and winter period characterized by a drastic reduction of airborne pollen. A study of the calendar reveals, furthermore, that: 1) Gramineae pollen is, amongst those of allergological importance, the most representative; 2)Parietaria is not perennial and is present in modest concentrations; 3)Olea reaches a high peak in June, but not as high as in other southern regions; 3) pollen from arboreal plants is prevalent compared to that of herbaceous plants.  相似文献   

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