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五味子属植物种子形态特征及其分类学意义   总被引:3,自引:0,他引:3  
在扫描电镜下观察了70多份五味子属种子样品,并拍摄了照片,其中34幅展示在文中。选取代表27个分类群,34个居群的36份种子样品,每份样品20粒,测量长、宽、厚,取平均值。采用“相对体积”这一新概念作为种子形态比较的一项指征。同时对种子整体照片所呈现的表面纹饰进行了分析归纳,将其分为4个类型:(1)平滑或基本平滑,(2)有明显的皱纹,或有或疏或密的疣状突起,(3)有密集而显著的乳头状突起,(4)密被不规则的、有结节的绳索状突起,突起物曲折蜿蜒,酷似哺乳动物的大脑。综合种子的大小、颜色、表面整体纹饰以及雄蕊群特征等分析的结果表明,少蕊组sect.Maximowiczia、五味子组sect.Schisandra和球蕊组sect.Sphaerostema的种子形态分别与其雄蕊群特征具有高度的相关性;而多蕊组sect.Pleiostema的情况稍微复杂一点,但种子形态与与其雄蕊群特征之间仍然有部分相关性。本文以种子的整体形态为基础讨论五味子属种子表面形态在该属分类上的意义。研究种子整体形态得到的证据与研究种子表面微形态得到的证据一致,不支持林祁(2000)和Saunders(2000)对五味子属的分类修订,也不支持刘玉壶(1996)将球蕊组sect.Sphaerostema划分成两个亚属的修订。  相似文献   

3.
The fossil record of primate and human evolution cannot provide accurate estimates of within species variation and integration. This means that we cannot directly observe how patterns of integration have evolved over time in this lineage. And yet, our interpretations of fossil diversity are awash with assumptions about variation patterning in precisely these fossil taxa. Most commonly, researchers rely on extant models of variation for interpreting past diversity, by assuming equality of variation (and occasionally covariation) among extant and fossil populations. Yet one of the things we know from studies of integration in primates is that patterns of morphological covariation can differ among even closely related taxa, indicating that they have diverged over evolutionary time, either in response to selection or as the result of neutral evolution. At the same time, overall patterns of integration remain remarkably similar, meaning that in many respects they are highly conserved evolutionarily. Taken together, these seemingly contradictory observations offer an important conceptual framework for interpreting patterns that we observe in the fossil past. This framework dictates that while we can use patterns of covariation in extant taxa as proxies for extinct diversity, and indeed their conserved nature makes them superior to approaches that rely on variation alone, we also need to account for the fact that such patterns change over time, and incorporate that into our models. Here I provide examples using covariation patterns estimated from modern humans and African great apes to demonstrate the extent to which divergence in covariance structure might affect our interpretations of hominin diversity.
Rebecca Rogers AckermannEmail:
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The transition from terrestrial ancestry to a fully pelagic life profoundly altered the body systems of cetaceans, with extreme morphological changes in the skull and feeding apparatus. The Oligocene Epoch was a crucial time in the evolution of cetaceans when the ancestors of modern whales and dolphins (Neoceti) underwent major diversification, but details of dental structure and evolution are poorly known for the archaeocete-neocete transition. We report the morphology of teeth and ultrastructure of enamel in archaeocetes, and fossil platanistoids and delphinoids, ranging from late Oligocene (Waitaki Valley, New Zealand) to Pliocene (Caldera, Chile). Teeth were embedded in epoxy resin, sectioned in cross and longitudinal planes, polished, etched, and coated with gold palladium for scanning electron microscopy (SEM) observation. SEM images showed that in archaeocetes, squalodontids and Prosqualodon (taxa with heterodont and nonpolydont/limited polydont teeth), the inner enamel was organized in Hunter-Schreger bands (HSB) with an outer layer of radial enamel. This is a common pattern in most large-bodied mammals and it is regarded as a biomechanical adaptation related to food processing and crack resistance. Fossil Otekaikea sp. and delphinoids, which were polydont and homodont, showed a simpler structure, with inner radial and outer prismless enamel. Radial enamel is regarded as more wear-resistant and has been retained in several mammalian taxa in which opposing tooth surfaces slide over each other. These observations suggest that the transition from a heterodont and nonpolydont/limited polydont dentition in archaeocetes and early odontocetes, to homodont and polydont teeth in crownward odontocetes, was also linked to a marked simplification in the enamel Schmelzmuster. These patterns probably reflect functional shifts in food processing from shear-and-mastication in archaeocetes and early odontocetes, to pierce-and-grasp occlusion in crownward odontocetes, with the implication of less demanding feeding biomechanics as seen in most extant odontocetes.  相似文献   

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The recently described fossil albuneid Paralbunea galantensis De Angeli and Marangon differs from the type of the genus Paralbunea Serène and is herein made the type species of a new genus, Harryhausenia , which is closely related to Zygopa Serène and Umali. A discussion is given on the relationships between the new genus and Zygopa , as well as between Zygopa and other albuneid taxa.  相似文献   

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Background

Commercial viewing and swimming with dusky dolphins (Lagenorhynchus obscurus) near Kaikoura, New Zealand began in the late 1980s and researchers have previously described changes in vocalisation, aerial behaviour, and group spacing in the presence of vessels. This study was conducted to assess the current effects that tourism has on the activity budget of dusky dolphins to provide wildlife managers with information for current decision-making and facilitate development of quantitative criteria for management of this industry in the future.

Methodology/Principal Findings

First-order time discrete Markov chain models were used to assess changes in the behavioural state of dusky dolphin pods targeted by tour vessels. Log-linear analysis was conducted on behavioural state transitions to determine whether the likelihood of dolphins moving from one behavioural state to another changed based on natural and anthropogenic factors. The best-fitting model determined by Akaike Information Criteria values included season, time of day, and vessel presence within 300 m. Interactions with vessels reduced the proportion of time dolphins spent resting in spring and summer and increased time spent milling in all seasons except autumn. Dolphins spent more time socialising in spring and summer, when conception occurs and calves are born, and the proportion of time spent resting was highest in summer. Resting decreased and traveling increased in the afternoon.

Conclusions/Significance

Responses to tour vessel traffic are similar to those described for dusky dolphins elsewhere. Disturbance linked to vessels may interrupt social interactions, carry energetic costs, or otherwise affect individual fitness. Research is needed to determine if increased milling is a result of acoustic masking of communication due to vessel noise, and to establish levels at which changes to behavioural budgets of dusky dolphins are likely to cause long-term harm. Threshold values from these studies would allow managers to set appropriate operational conditions based on quantifiable criteria.  相似文献   

8.
Allan J.  Baker 《Journal of Zoology》1975,175(3):357-390
Variation in eight morphological variables was analysed for the three New Zealand species of oystercatchers, Haematopus ostralegus finschi , Martens, H. unicolor , Forster, and H. chathamensis , Hartert. Within species, significant size variation was detected among age classes and between the sexes, making it necessary to use measurements only from adults and to treat the sexes separately in ensuing taxonomic comparisons. Analysis of morphological variation in hybridizing forms of H. unicolor suggests that gene exchange between the parental black and pied phases is extensive. Univariate and multivariate statistical analyses isolated three phenetic entities, consistent with three species as proposed in recent classification.  相似文献   

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Paleontological Journal - Lower Permian conifers of the Cis-Urals are reviewed, their morphological features are considered. The data on the investigated sections of the Artinskian and Kungurian of...  相似文献   

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Background

Acisarcuatus variradius gen. et sp. nov., an extinct new species representing a new genus, is described from the Middle Jurassic Jiulongshan Formation in Daohugou Village, Inner Mongolia, China.

Methodology/Principal Findings

In this paper, we revised the diagnosis of Necrotauliidae Handlirsch, 1906. One new genus and species of Necrotauliidae is described. An analysis based on the fossil morphological characters clarified the taxonomic status of the new taxa.

Conclusions/Significance

New fossil evidence supports the viewpoint that the family Necrotauliidae belongs to the Integripalpia.  相似文献   

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《Palaeoworld》2020,29(4):752-760
A new fossil occurrence of Ostrya (Betulaceae) is reported based on 14 involucre impressions from the lower Oligocene of Löhe Basin, Yunnan Province, Southwest China. They are characterized by their bladder-like shape with longitudinal veins and perpendicular or branched intercostal veins that form a reticulate venation. The discovery of these fossil involucres represents the earliest unequivocal fossil record of Ostrya in East Asia and the record at the lowest latitude. Its fossil history suggests that the modern distribution pattern of Ostrya might have been established since the early Oligocene, and that this genus has inhabited low altitude areas since then.  相似文献   

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Background

The family Phyllanthaceae has a predominantly pantropical distribution. Of its several genera, Bridelia Willd. is of a special interest because it has disjunct equally distributed species in Africa and tropical Asia i.e. 18–20 species in Africa-Madagascar (all endemic) and 18 species in tropical Asia (some shared with Australia). On the basis of molecular phylogenetic study on Bridelia, it has been suggested that the genus evolved in Southeast Asia around 33±5 Ma, while speciation and migration to other parts of the world occurred at 10±2 Ma. Fossil records of Bridelia are equally important to support the molecular phylogenetic studies and plate tectonic models.

Results

We describe a new fossil leaf of Bridelia from the late Oligocene (Chattian, 28.4–23 Ma) sediments of Assam, India. The detailed venation pattern of the fossil suggests its affinities with the extant B. ovata, B. retusa and B. stipularis. Based on the present fossil evidence and the known fossil records of Bridelia from the Tertiary sediments of Nepal and India, we infer that the genus evolved in India during the late Oligocene (Chattian, 28.4–23 Ma) and speciation occurred during the Miocene. The stem lineage of the genus migrated to Africa via “Iranian route” and again speciosed in Africa-Madagascar during the late Neogene resulting in the emergence of African endemic clades. Similarly, the genus also migrated to Southeast Asia via Myanmar after the complete suturing of Indian and Eurasian plates. The emergence and speciation of the genus in Asia and Africa is the result of climate change during the Cenozoic.

Conclusions

On the basis of present and known fossil records of Bridelia, we have concluded that the genus evolved during the late Oligocene in northeast India. During the Neogene, the genus diversified and migrated to Southeast Asia via Myanmar and Africa via “Iranian Route”.  相似文献   

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Halimeda is a genus of calcified and segmented green macroalgae in the order Bryopsidales. In New Caledonia, the genus is abundant and represents an important part of the reef flora. Previous studies recorded 19 species that were identified using morphological criteria. The aim of this work was to reassess the diversity of the genus in New Caledonia using morpho‐anatomical examinations and molecular analyses of the plastid tufA and rbcL genes. Our results suggest the occurrence of 22 species. Three of these are reported for the first time from New Caledonia: Halimeda kanaloana, H. xishaensis, and an entity resembling H. stuposa. DNA analyses revealed that the species H. fragilis exhibits cryptic or pseudocryptic diversity in New Caledonia. We also show less conclusive evidence for cryptic species within H. taenicola  相似文献   

16.
Mapping morphological characters on a molecular-based phytogeny enabled examination of character evolution and an historical perspective into evolutionary processes, both of which are important aspects of systematic research and comparative biology. In this study, 63 morphological characters from hepialid moths in New Zealand were mapped on a phylogenetic tree reconstructed from mitochondrial DNA COI & II sequence data. Morphological characters hypothesized to be synapomorphies for the New Zealand 'Oxycanus' lineages and 'Oxycanus' lineage s.s. were confirmed to be homologous when mapped on the COI & II phytogeny. The direction of character state transformation was determined for five characters, with members of the Aenetus and Aoraia lineages exhibiting hypothesized ancestral states. Male genitalic characters were less homoplasious than other character partitions and covaried significandy with phytogeny.  相似文献   

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The Parachlorella clade was put forward as a group within the family Chlorellaceae in 2004. Recent molecular analyses have revealed that Dictyosphaerium morphotype algae form several independent lineages within the Parachlorella clade, and new genera and species have been established. In this study, we focus on the diversity of Dictyosphaerium morphotype algae within the Parachlorella clade, based on 42 strains from China. We used combined analyses of morphology and molecular data based on SSU and internal transcribed spacer region (ITS) rDNA sequences to characterize these algae. In addition, the secondary structure of ITS2 was compared to delineate new lineages. Our results revealed high phylogenic diversity of Dictyosphaerium morphotype algae, and we describe five distinct lineages. We examined the morphological features of these five lineages, and morphological differences are difficult to find compared with other Dictyosphaerium morphotype algae. The five distinct lineages were not described as new genera currently. We lastly discuss the taxonomic problems regarding the Dictyosphaerium morphotype within the Parachlorella clade, and possible solutions are considered.  相似文献   

18.
We describe an Oligocene newt specimen from western Germany that has gone practically unnoticed in the literature despite having been housed in the Museum für Naturkunde (Berlin) for a century. It is referable to the coeval Chelotriton, but is unusually peramorphic; for many characters it is more peramorphic than all other caudates or even all other lissamphibians. Most noticeable are the position of the jaw joints far caudal to the occiput, the honeycombed sculpture on the maxilla, and the possible presence of a septomaxilla (which would be unique among salamandrids). Referral to a species would require a revision of the genus, but the specimen likely does not belong to the type species. A phylogenetic analysis of nonmolecular characters of Salamandridae, far larger than all predecessors, confirms the referral to Chelotriton. It further loosely associates the Oligocene Archaeotriton and the Miocene Carpathotriton with the extant Lissotriton, though the former may alternatively lie outside Pleurodelinae altogether. The Miocene? I. randeckensis may not belong to the extant Ichthyosaura. The Miocene “Triturus” roehrsi is found neither with the extant Ommatotriton nor with Lissotriton, but inside an Asian/aquatic clade or, when geographic distribution is included as a character, as the sister-group to all other European molgins. The main cause for discrepancies between the results and the molecular consensus is not heterochrony, but adaptations to a life in mountain streams; this is the most likely reason why the Paleocene Koalliella from western Europe forms the sister-group to some or all of the most aquatic extant newts in different analyses. We would like to urge neontologists working on salamandrids to pay renewed attention to the skeleton, not limited to the skull, as a source of diagnostic and phylogenetically informative characters.  相似文献   

19.
The modern New Zealand flora has a relatively low number of families and genera in relation to land area, but well-preserved macrofossils and pollen from three sites in southern New Zealand suggest that the floras in Eocene, Oligocene and Miocene times were much more diverse at the generic level. At Pikopiko, Southland, a late Eocene in situ forest with fern understory was dominated by conifers, Casuarinaceae, Lauraceae, Nothofagus, Proteaceae, and mesothermal angiosperms including palms (aff. Calamus), Sapindaceae: Cupaniae and Picrodendraceae. At Newvale Mine, Southland, a leaf bed within a thick lignite seam represents leaf fossils preserved in a late Oligocene oligotrophic bog. This site demonstrates that Agathis, Dacrycarpus, Dacrydium, Halocarpus, Microcachrys, Podocarpus and Phyllocladus coexisted with diverse angiosperms including Nothofagus, Gymnostoma, Cunoniaceae, Ericaceae, Sapindaceae and several Proteaceae. Pollen data add Meliaceae, Myrtaceae, Onagraceae and Rubiaceae to the flora. At Foulden Maar, Otago, mummified leaves and flowers, including several with in situ pollen, demonstrate the existence of a diverse flora surrounding an Early Miocene lake. This site contains numerous monocot macrofossils including Astelia, Cordyline, Ripogonum and Typha, as well as the oldest fossils known for Orchidaceae and Luzuriagaceae. This flora was dominated by Lauraceae with affinities to Cryptocarya and Litsea, but other families include Araliaceae, Cunoniaceae, Elaeocarpaceae, Euphorbiaceae sensu lato, Menispermaceae, Myrsinaceae, Myrtaceae, Onagraceae, Proteaceae and Sterculiaceae. Many ferns, conifers, and Nothofagus are from lineages with Gondwanan ancestors, whereas other taxa show links to Australia (e.g., Gyrostemonaceae), New Caledonia (e.g., Beauprea) and South America (e.g., Luzuriaga, Fuchsia). Many of these taxa are now extinct in New Zealand, and therefore indicate much wider biogeographic ranges for many families and genera in the past.  相似文献   

20.
Eucolaspis Sharp 1886 is a New Zealand native leaf beetle genus (Coleoptera: Chrysomelidae: Eumolpinae) with poorly described species and a complex taxonomy. Many economically important fruit crops are severely damaged by these beetles. Uncertain species taxonomy of Eucolaspis is leaving any biological research, as well as pest management, tenuous. We used morphometrics, mitochondrial DNA and male genitalia to study phylogenetic and geographic diversity of Eucolaspis in New Zealand. Freshly collected beetles from several locations across their distribution range, as well as identified voucher specimens from major museum collections were examined to test the current classification. We also considered phylogenetic relationships among New Zealand and global Eumolpinae (Coleoptera: Chyrosomelidae). We demonstrate that most of the morphological information used previously to define New Zealand Eucolaspis species is insufficient. At the same time, we show that a combination of morphological and genetic evidence supports the existence of just 3 mainland Eucolaspis lineages (putative species), and not 5 or 15, as previously reported. In addition, there may be another closely related lineage (putative species) on an offshore location (Three Kings Islands, NZ). The cladistic structure among the lineages, conferred through mitochondrial DNA data, was well supported by differences in male genitalia. We found that only a single species (lineage) infests fruit orchards in Hawke’s Bay region of New Zealand. Species-host plant associations vary among different regions.  相似文献   

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