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1.
An updated angiosperm classification   总被引:5,自引:0,他引:5  
DAHLGREN, C, 1989. An updated angiosperm classification. A new two-dimensional diagram, reflecting the system of classification of the angiosperms, is presented. It combines the dicotyledon diagram in G. Dahlgren (1989) and an adapted monocotyledon diagram after that in Dahlgren (1985) in a single diagram. An updated monocotyledon taxonomy is presented and the classification is appended.  相似文献   

2.
何云核 《生物学杂志》2010,27(4):99-100
经过多年的教学与科研实践,作者发现了被子植物两种新脉型,分别命名为假三出脉和平行三出脉,在此提出与同行商榷。  相似文献   

3.
A revised classification of the higher taxa of the Ostracoda (Crustacea)   总被引:1,自引:1,他引:1  
Alexander Liebau 《Hydrobiologia》2005,538(1-3):115-137
Focusing on palaeontological data from the literature of the last four decades, a new classification of the Ostracoda is outlined. The superorder Podocopomorpha is accepted as a mantle term for the ‘P-orders’ Palaeocopida, Punciocopida, Platycopida and Podocopida; its counterpart are the Myodocopomorpha (Cypridinida, Halocypridida and ? Leperditicopida). The Podocopida comprise the suborders Bairdiocopina, Cytherocopina, Sigilliocopina, Cypridocopina, Darwinulocopina and Healdiocopina (n.;=Metacopina s.s.). The non-calcifying ostracodomorph arthropods (Archaeocopida and Phosphatocopida) of the Early Palaeozoic, now excluded from the Ostracoda by many authors, are also considered briefly.  相似文献   

4.
Phylogenetic evidence for the herbaceous origin of angiosperms   总被引:7,自引:0,他引:7  
The ancestral angiosperm is commonly interpreted as an arborescent to shrubby magnolialean with large, multiparted, complex flowers. We examined this hypothesis using a phylogenetic analysis of new and reevaluated characters polarizabled with outgroup comparison. Our cladistic analysis of basal angiosperms placed the nonmagnolialeanChloranthaceae andPiperaceae at the bottom of the tree. We further inferred the probable ancestral states of characters not polarizable with outgroup comparison by examining their distribution among taxa at the base of our cladogram. The sum of ancestral character states suggests that the protoangiosperm was a diminutive, rhizomatous to scrambling perennial herb, with small, simple flowers.  相似文献   

5.
Traditionally, the morphological traits of primates were assumed to be adaptations to an arboreal way of life. However, Cartmill [1972] pointed out that a number of morphological traits characteristic of primates are not found in many other arboreal mammals. He contends that orbital convergence and grasping extremities indicate that the initial divergence of primates involved visual predation on insects in the lower canopy and undergrowth of the tropical forest. However, recent research on nocturnal primates does not support the visually-oriented predation theory. Although insects were most likely important components of the diets of the earliest euprimates, it is argued here that visual predation was not the major impetus for the evolution of the adaptive traits of primates. Recent paleobotanical research has yielded evidence that a major evolutionary event occurred during the Eocene, involving the angiosperms and their dispersal agents. As a result of long-term diffuse coevolutionary interactions with flowering plants, modern primates, bats, and plant-feeding birds all first arose around the Paleocene-Eocene boundary and became the major seed dispersers of modern tropical flora during the Eocene. Thus, it is suggested here that the multitude of resources available on the terminal branches of the newly evolved angiosperm, rain forest trees led to the morphological adaptations of primates of modern aspect.  相似文献   

6.
Over the past 25 years, discoveries of Early Cretaceous fossil flowers, often associated with pollen and sometimes with vegetative parts, have revolutionized our understanding of the morphology and diversity of early angiosperms. However, few of these fossils have been integrated into the increasingly robust phylogeny of living angiosperms based primarily on molecular data. To remedy this situation, we have used a morphological dataset for living basal angiosperms (including basal eudicots and monocots) to assess the most parsimonious positions of early angiosperm fossils on cladograms of Recent plants, using constraint trees that represent the current range of hypotheses on higher-level relationships, and concentrating on Magnoliidae (the clade including Magnoliales, Laurales, Canellales, and Piperales) and eudicots. In magnoliids, our results confirm proposed relationships of Archaeanthus (latest Albian?) to Magnoliaceae, Endressinia (late Aptian) to Magnoliales (the clade comprising Degeneria, Galbulimima, Eupomatia, and Annonaceae), and Walkeripollis pollen tetrads (late Barremian?) to Win-teraceae, but they indicate that Mauldinia (early Cenomanian) was sister to both Lauraceae and Hernandiaceae rather than to Lauraceae alone. Among middle Albian to early Cenomanian eudicots, we confirm relationships of Nelumbites to Nelumbo, platanoid inflorescences and Sapindopsis to Platanaceae, and Spanomera to Buxaceae. With the possible exception of Archaeanthus, these fossils are apparently not crown group members of living families but rather stem relatives of one or more families.  相似文献   

7.
The subtribal classification of the tribe Phaseoleae has drifted into disorder since Bentham's (1865) scheme in the Genera Plantarum. A revised classification is here proposed, which for the first time accounts for all of the currently recognized genera. This classification has seven subtribes: Cajaninae, Diocleinae, Kennediinae, Phaseolinae, Glycininae, Ophrestiinae, and Erythrininae, of which the Ophrestiinae is new. A survey for the free amino acid, canavanine, shows that it is most often present in the Diocleinae and Kennediinae and frequently absent in the rest of the tribe.  相似文献   

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9.
盲蝽科昆虫的分类系统概述   总被引:1,自引:0,他引:1  
齐宝瑛  郑哲民 《昆虫知识》2003,40(2):101-107
依据目前已有的资料 ,概述了盲蝽科昆虫的分类系统。盲蝽科隶属于半翅目异翅亚目臭虫型的盲蝽总科 ,这在半翅目学者中意见一致。但关于盲蝽科亚科及族级水平的分类系统观点不一。最合理的为 6亚科及 8亚科的分类系统。8亚科分类系统是目前最被接受和应用的系统。  相似文献   

10.
The restricted distributions of some classes of secondary metabolites in the angiosperms make them valuable taxonomic characters in assessing systematic relationships at higher levels of classification. Yet, for several reasons, secondary metabolites have not, until recently, been widely used as taxonomic characters above the family level. In this paper, the distributions of a number of classes of secondary compounds are discussed with reference to four recently published systems of higher angiosperm classification: Cronquist's of 1981, Dahlgren's of 1980, Takhtajan's of 1980 and Thome's of 1981. Some of the problems faced in choosing and using secondary metabolite data for systematic purposes (including the effects of our increasing understanding of their functional significance) are covered as well. Among the classes of secondary compounds treated here, benzylisoquinoline alkaloids, iridoids and be–talains are shown to be the most important systematic markers used at present at higher levels of classification, although glucosinolates, polyacetylenes and some other types of alkaloids are also demonstrated to be valuable criteria for making taxonomic judgments above the family rank. In addition, certain terpenoids, flavonoids, phenolics, cyanogenic glycosides and non–protein amino acids are illustrated to be of systematic use in particular cases.  相似文献   

11.
Eudicot flowering plants comprise roughly 70% of land plant species diversity today, but their early evolution is not well understood. Fossil evidence has been largely restricted to their distinctive tricolpate pollen grains and this has limited our understanding of the ecological strategies that characterized their primary radiation. I describe megafossils of an Early Cretaceous eudicot from the Potomac Group in Maryland and Virginia, USA that are complete enough to allow reconstruction of important life-history traits. I draw on quantitative and qualitative analysis of functional traits, phylogenetic analysis and sedimentological evidence to reconstruct the biology of this extinct species. These plants were small and locally rare but widespread, fast-growing herbs. They had complex leaves and they were colonizers of bright, wet, disturbance-prone habitats. Other early eudicot megafossils appear to be herbaceous rather than woody, suggesting that this habit was characteristic of their primary radiation. A mostly herbaceous initial diversification of eudicots could simultaneously explain the heretofore sparse megafossil record as well as their rapid diversification during the Early Cretaceous because the angiosperm capacity for fast reproduction and fast evolution is best expressed in herbs.  相似文献   

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13.
The classic leaf fossil floras from the Cretaceous of the Lusitanian Basin, Portugal, which were first described more than one hundred years ago, have played an important role in the development of ideas on the early evolution of angiosperms. Insights into the nature of vegetational change in the Lusitanian Basin through the Cretaceous have also come from studies of fossil pollen and spores, but the discovery of a series of mesofossil floras containing well-preserved angiosperm reproductive structures has provided a new basis for understanding the systematic relationships and biology of angiosperms at several stratigraphic levels through the Cretaceous. In the earliest mesofossil floras from the Torres Vedras locality, which are of probable Late Barremian-Early Aptian age, angiosperms are surprisingly diverse with about 50 different taxa. In slightly later mesofossil floras, which are of probable Late Aptian-Early Albian age, the diversity of angiosperms is still more substantial with more than hundred different kinds of angiosperm reproductive structures recognized from the Famalicão locality alone. However, this early diversity is largely among angiosperm lineages that produced monoaperturate pollen (e.g., Chloranthaceae, Nymphaeales) and early diverging monocots (Alismatales). Eudicots are rare in these Early Cretaceous mesofossil floras, but already by the Late Cenomanian the vegetation of the western Iberian Peninsula is dominated by angiosperms belonging to various groups of core eudicots. The Normapolles complex is a particularly conspicuous element in both mesofossil floras and in palynological assemblages. In the Late Cretaceous mesofossil floras from Esgueira and Mira, which are of Campanian-Maastrichtian age, core eudicots are also floristically dominant and flowers show great organisational similarity to fossil flowers from other Late Cretaceous floras described from other localities in Asia, Europe and North America.  相似文献   

14.
The Asclepiadaceae, as traditionally defined, have repeatedly been shown to be an apomorphic derivative of the Apocynaceae. It has often been recommended that the Asclepiadaceae be subsumed within the Apocynaceae in order to make the latter monophyletic. To date, however, no comprehensive, unified classification has been established. Here we provide a unified classification for the Apocynaceae, which consists of 424 genera distributed among five subfamilies: Rauvolfioideae, Apocynoideae, Periplocoideae, Secamonoideae, and Asclepiadoideae. Keys to the subfamilies and tribes are provided, with lists of genera that (as far as we have been able to ascertain) are recognized in each tribe.  相似文献   

15.
A revised infrageneric classification of Nothofagus (Fagaceae)   总被引:1,自引:0,他引:1  
HILL, R. S. & READ, J., 1991. A revised infrageneric classification of Nothofagus (Fagaceae). An examination of cupule morphology, leaf architecture and cuticular morphology of Nothofagus species demonstrates that the existing infrageneric classifications are inaccurate. Four subgenera are proposed, based on these characteristics as well as other morphological information. This analysis indicates that the traditional pollen groupings of Nothofagus closely reflect the infrageneric taxonomy. It is hypothesized that deciduousness is primitive in Nothofagus , and the evergreen habit has arisen more than once, and therefore the deciduous or evergreen habit is invalid as a primary taxonomic character.  相似文献   

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18.
A revised classification of the Gymnamoebia (Protozoa: Sarcodina)   总被引:1,自引:0,他引:1  
A revised classification of the naked amoebae is proposed on the basis of a synthesis of many kinds of information presently available for taxonomic purposes above the species level. These amoebae, constituting the subclass Gymnamoebia within the class Lobosea, superclass Rhizopoda, include not only strictly lobose amoebae but also those with more or less filose subpseudopodia produced from a broader hyaline lobe. The subclass is divided into the orders Amoebida, Schizopyrenida, and Pelobiontida, and suborders are recognized within the order Amoebida. Although the Gymnamoebia are undoubtedly heterogeneous and polyphyletic and the proposed classification is intended chiefly as a practical system with a logical basis, there are a few suggestions of natural relationships.  相似文献   

19.
白蚁分类方法述评   总被引:7,自引:0,他引:7  
从白蚁的形态特征、表皮碳氢化合物的化学分析、分子生物学等方面阐述白蚁的分类体系。此外,通过白蚁的生活方式,在自然界中的作用,及环境、地质史等因子对白蚁的影响等方面来探讨白蚁多样性的。  相似文献   

20.
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