中国中生代的马通蕨科植物:化石记录、多样性与时空分布特征*

现生真蕨目马通蕨科(Matoniaceae)植物仅存Matonia和Phanerosorus两属, 集中分布于马来西亚、印度尼西亚等热带地区。马通蕨科植物在中生代时期全球广布, 且主要分布于热带、亚热带地区, 有近9个属, 被作为热带、亚热带气候的标志性植物化石之一。本文梳理总结了中国中生代的马通蕨科化石记录并分析其多样性特征, 共计有2属16种, 包括异脉蕨属(Phlebopteris) 15种和准马通蕨属(Matonidium) 1种。对其化石记录和地质地理分布分析表明, 晚三叠世时期, 异脉蕨属植物广泛分布于热带—亚热带湿热气候区, 包括华南一带的四川、湖北、 云南、西藏、福建等地; 早侏罗世时期, 其分布逐渐向北方扩展, 在南、北方植物区系界线附近均有发现; 中侏罗世局限于湖北、青海等地; 早白垩世时仅在黑龙江和西藏少量发现。准马通蕨属仅在黑龙江地区的早白垩世地层中发现。整体上, 马通蕨科在中国中生代的分布范围变迁与气候带范围变化相吻合。     

Conservation on diversity and distribution patterns of endemic birds in China

The diversity and distribution patterns of endemic species of birds inChina have been studied on the basis of the distribution database of specimencollections and published references. One hundred and two endemic species ofbirds in China, belonging to 53 genera, 16 families and 8 orders are recognized.They account for 8.1% of the total species of China. The distribution patternswere studied and three centers of endemism were found, includingHengduanshan Mountains, mountain areas of western Qinling, north Sichuan Province andSouth Gansu Province, as well as Taiwan Island, which are suggested as conservationpriorities based on endemism. Twenty-four endemics are rare and endangered, listedin the China Red Data Book of Endangered Animals. Among them, 15 species are in rankI and 9 species are in rank II. The study results are to be beneficial tofurther study on both the processing mechanism of the distribution patterns andon the priority of the diversity and endemism conservation.     

The diversity and distribution of diatoms: from cosmopolitanism to narrow endemism

It has been claimed that microbial taxa will not exhibit endemism because their enormous populations remove dispersal as an effective constraint on geographical range. Here we review evidence that challenges this ubiquity hypothesis for the most speciose group of microbial eukaryotes, the diatoms. Detailed taxonomic inventories using fine-grained morphological characteristics, molecular markers, and crossing experiments have revealed that the geographic distribution of diatoms ranges from global to narrow endemic. Records of human-mediated introductions of exotic species further provide a strong indication that geographic dispersal was limiting in the past. Finally, recent studies have revealed that diatom community structure and diversity are influenced by geographical factors independent of environmental conditions. Diatom communities are thus regulated by the same processes that operate in macro-organisms, although possibly to a different degree, implying that dispersal limitation is significant and the endemism observed in isolated areas is real. These results underscore the pressing need to (1) continue research into diatom biology, ecology and the factors driving diatom species diversity and geographic distributions, and (2) protect relatively isolated areas against further introductions of exotic species. Special Issue: Protist diversity and geographic distribution. Guest editor: W. Foissner.     

Extinction,diversity and survivorship of taxa in the fossil record

Using data drawn from large-scale databases, a number of interesting trends in the fossil record have been observed in recent years. These include the average decline in extinction rates throughout the Phanerozoic, the average increase in standing diversity, correlations between rates of origination and extinction, and simple laws governing the form of survivorship curves and the distribution of the lifetimes of taxa. In this paper we derive a number of mathematical relationships between these quantities and show how these different trends are interrelated. We also derive a variety of constraints on the possible forms of these trends, such as limits on the rate at which extinction may decline and limits on the allowed difference between extinction and origination rates at any given time.     

The fossil record and biogeography of the Ciehlidae (Actinopterygii: Labroidei)

The family Ciehlidae is a large group of tropical fishes in the order Perciformes, with an estimated number of living species exceeding 1400. The modern distribution of the family Ciehlidae is predominantly in fresh waters of Central and South America, Africa, Madagascar, India and the Middle East, with fossil members known from Africa, Saudi Arabia, the Levant, Europe, South America and Haiti. Many authors have referred to the distribution as being Gondwanan and have postulated that cichlids originated over 130 million years ago, in the Early Cretaceous. However, the suggested evidence for an Early Cretaceous origin of cichlids is equally or more compatible with a much younger age of origin. Based on the biology and distribution of modern and fossil cichlids, it is more probable that they arose less than 65 million years ago, in the Early Tertiary, and crossed marine waters to attain their current distribution.     

Genetic diversity and dispersal of Phragmites australis in a small river system

Even though the reed, Phragmites australis, is an extensively studied wetland species, little is known about reproduction and dispersal modes within and among reed populations at the scale of small river systems. Using microsatellite analysis of 189 individuals from three adjacent river catchments in the Czech Republic, we elucidated the role of the river corridors in the dispersal of P. australis. Using Bayesian clustering of individuals, we found that 19% of clusters were distributed only along one river, which implied dispersal by water (or by wind) along river corridors, whereas 38% of clusters were widely distributed and were likely the product of wind long-distance dispersal among rivers. Intensive exchange of propagules among river systems is further demonstrated by only 6% of total variance being attributed to the variance among rivers in the AMOVA-analysis. Spatial autocorrelation analysis revealed a decreasing pattern up to 5–10 km and no clear pattern over longer distances. This gives an evidence for pollen and seed dispersal at short distances (up to 1 km), whereas most likely only seed dispersal at longer distances up to 10 km. We found five multilocus genotypes distributed in two different populations. The distances between populations with the same genotype ranged from 0.5 to 10.8 km. This can be interpreted as long-distance vegetative dispersal.     

Diatom communities from the sub-Antarctic Prince Edward Islands: diversity and distribution patterns

During an extensive survey of the freshwater and moss-inhabiting diatoms of the Prince Edward Islands, a total of 214 taxa belonging to 60 genera were found. Three main communities can be found on the two islands. A large part of the samples was grouped into an aquatic group, bringing together all samples from lentic and lotic waterbodies. A second, contrasting, group was formed by all dry samples whereas in a third group all habitats with higher mineral contents were found. The habitats differed clearly in taxa composition reflecting that way possible environmental differences. Although the diatom composition between the two islands of this island group (Marion and Prince Edward Island) showed some minor qualitative differences, no marked quantitative differences have been observed. The diatom flora shows a distinct similarity with the other islands in the southern Indian Ocean, such as the Crozet archipelago and the Kerguelen Islands forming a biogeographical entity in this part of the ocean, distinctly separated from the non-marine diatom flora in other parts of the (sub-)Antarctic Region.     

Global diversity of true and pygmy grasshoppers (Acridomorpha,Orthoptera) in freshwater

A small percentage of Orthoptera Acridomorpha is comprised species dependant on continental water ecosystems. However, as phytophagous insects, they are important at the basis of the trophic chain, mainly in regions with large permanent biota resulting from the pulses of the rivers. An assessment of the composition and origin of the populations from different biogeographical regions is attempted, and the state of our current knowledge is given in Tables 1, 2 and 3. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens Freshwater Animal Diversity Assessment     

Dinoflagellate diversity and distribution

Dinoflagellates are common to abundant in both marine and freshwater environments. They are particularly diverse in the marine plankton where some cause “red tides” and other harmful blooms. More than 2,000 extant species have been described, only half of which are photosynthetic. They include autotrophs, mixotrophs and grazers. They are biochemically diverse, varying in photosynthetic pigments and toxin production ability. Some are important sources of bioluminescence in the ocean. They can host intracellular symbionts or be endosymbionts themselves. Most of the photosynthetic “zooxanthellae” of invertebrate hosts are mutualistic dinoflagellate symbionts, including all those essential to reef-building corals. Roughly 5% are parasitic on aquatic organisms. The fossil record, consisting of more than 2,500 species, shows a rapid radiation of cysts, starting in the Triassic, peaking in the Cretaceous, and declining throughout the Cenozoic. Marine species with a benthic, dormant cyst stage are confined to the continental shelf and fossil cysts can be used as markers of ancient coastlines. Northern and southern hemispheres contain virtually identical communities within similar latitudes, separated by a belt of circumtropical species. A few endemics are present in tropical and polar waters. Some benthic dinoflagellates are exclusively tropical, including a distinct phycophilic community, some of which are responsible for ciguatera fish poisoning. In lakes chemical and grazing effects can be important. Predatory dinoflagellates co-occur with their prey, often diatoms. Special Issue: Protist diversity and geographic distribution. Guest editor: W. Foissner.     

A technique for using hair tubes beneath the snowpack to detect winter-active small mammals in the subnivean space

The study of winter-active small mammals beneath the snowpack has proved challenging for researchers because of the relative inaccessibility. We present a technique using hair tubes that permits the detection of small mammals active in the subnivean space. Hair tubes are cylindrical or funnel-shaped structures containing suitable bait and an adhesive surface that harvests hairs from small mammals as they attempt to reach the bait. Hair tubes eliminate many of the difficulties often associated with live trapping and permit the expansion of systematic sampling to larger scales than allowed by conventional live-trapping methods. The technique was used successfully to detect five small mammal species in the subnivean space in Kosciuszko National Park (KNP) in southeastern Australia. These included the common bush-rat, Rattus fuscipes; the dusky and agile antechinus, Antechinus swainsonii and A. agilis; the broad-toothed rat, Mastacomys fuscus; and the mountain pygmy possum, Burramys parvus. Although hair tubes have a number of limitations, such as not providing a measure of abundance or allowing the identification of individual animals, we believe that these limitations are balanced by the fact that the technique can be used at any spatial scale. Hair tubes are particularly suited to studies of animal distribution at the landscape-scale, because many hair tubes can be deployed and dispersed over large areas, and monitored on a regular basis by a small team of researchers. The technique also makes use of readily available, low-cost materials and could be easily adapted to a range of conditions and different target species.     

Preface: The phylogeny, fossil record and ecological diversity of ostracod crustaceans

After more than two centuries of research, more than 65,000 living and fossil ostracod species have been described and studied, yet much remains to be learned about this ancient, widespread and diverse group of bivalved arthropods. Their higher classification and phylogeny are subjects of vigorous debate, as is their position in the broader picture of crustacean phylogeny. At the same time, major advances in our understanding of ostracod lineages and their relationships are resulting from the application of innovative approaches and techniques. This preface provides a contextual overview of the 15 contributions to this volume, which resulted from the 14th International Symposium on Ostracoda (ISO2001) held in 2001at Shizuoka, Japan. As such it provides a cross-section of topics at the forefront of research on the evolution and diversity of Ostracoda, and indicates directions for future work.     

The quality of the fossil record and the accuracy of phylogenetic inferences about sampling and diversity

Because phylogenies can be estimated without stratigraphic data and because estimated phylogenies also infer gaps in sampling, some workers have used phylogeny estimates as templates for evaluating sampling from the fossil record and for "correcting" historical diversity patterns. However, it is not known how sampling intensity (the probability of sampling taxa per unit time) and completeness (the proportion of taxa sampled) affect the accuracy of phylogenetic inferences, nor how phylogenetically inferred estimates of sampling and diversity respond to inaccurate estimates of phylogeny. Both issues are addressed with a series of simulations using simple models of character evolution, varying speciation patterns, and various rates of speciation, extinction, character change, and preservation. Parsimony estimates of simulated phylogenies become less accurate as sampling decreases, and inaccurate trees chronically underestimate sampling. Biotic factors such as rates of morphologic change and extinction both affect the accuracy of phylogenetic estimates and thus affect estimated gaps in sampling, indicating that differences in implied sampling need not reflect actual differences in sampling. Errors in inferred diversity are concentrated early in the history of a clade. This, coupled with failure to account for true extinction times (i.e., the Signor-Lipps effect), inflates relative diversity levels early in clade histories. Because factors other than differences in sampling predict differences in the numbers of gaps implied by phylogeny estimates, inferred phylogenies can be misleading templates for evaluating sampling or historical diversity patterns.     

Vertebrate cranial evolution: Contributions and conflict from the fossil record

In modern vertebrates, the craniofacial skeleton is complex, comprising cartilage and bone of the neurocranium, dermatocranium and splanchnocranium (and their derivatives), housing a range of sensory structures such as eyes, nasal and vestibulo-acoustic capsules, with the splanchnocranium including branchial arches, used in respiration and feeding. It is well understood that the skeleton derives from neural crest and mesoderm, while the sensory elements derive from ectodermal thickenings known as placodes. Recent research demonstrates that neural crest and placodes have an evolutionary history outside of vertebrates, while the vertebrate fossil record allows the sequence of the evolution of these various features to be understood. Stem-group vertebrates such as Metaspriggina walcotti (Burgess Shale, Middle Cambrian) possess eyes, paired nasal capsules and well-developed branchial arches, the latter derived from cranial neural crest in extant vertebrates, indicating that placodes and neural crest evolved over 500 million years ago. Since that time the vertebrate craniofacial skeleton has evolved, including different types of bone, of potential neural crest or mesodermal origin. One problematic part of the craniofacial skeleton concerns the evolution of the nasal organs, with evidence for both paired and unpaired nasal sacs being the primitive state for vertebrates.     

Atomism, transformism and the fossil record

The modern debate between exponents of classical evolutionary classification and of cladistic analysis of phylogenetic relationships mirrors to some extent the arguments that were put forward in the debate between Cuvier and Geoffroy Saint-Hilaire in 1830. Put into a historical perspective the problems of comparative biology centre around two complementary traditions, atomism and transformism.     

The latitudinal position of peak marine diversity in living and fossil biotas

Aim Peak marine taxonomic diversity has only rarely occurred at or near the equator during the Phanerozoic Eon, in contrast to the present‐day pattern. This fundamental difference is difficult to reconcile because the latitude at which peak diversity occurs for living marine taxa has not yet been explicitly determined at a broad taxonomic and spatial scale. Here, we attempt to determine this value in order to compare the contemporary and fossil patterns directly. Location Our data are global in coverage. Methods We used a literature compilation of 149 present‐day marine latitudinal diversity gradients. We summed the number of marine taxa that exhibited peak diversity within 10° latitudinal bins. In addition, we recorded locality data, general habitat (benthic/pelagic), and the taxonomic level of the study organisms. Results We found that peak diversity for most sampled marine taxa currently occurs between 10° and 20° N, even after correcting for a Northern Hemisphere sampling bias. Moreover, this peak position is a global phenomenon: it is found across habitats and higher taxa, within all sampled ocean basins, and on both sides of the Atlantic and Pacific oceans. Benthic taxa, which dominate our data, exhibit one peak at 10°–20° N, while pelagic taxa exhibit a peak at 10°–20° N and an additional peak at 10°–20° S, producing a distinct trough at the equator. Main conclusions Our data indicate that peak marine diversity for many taxa is currently within 10°–20° N rather than at the equator, and that this is not likely to result from either undersampling at lower latitudes or the pattern being dominated by a particular taxon. Possible explanations may include a coincidence with the intertropical convergence zone, a mid‐domain effect, abundant shallow marine habitat, or high ocean temperatures at latitudes nearest the equator. Regardless of its exact cause, the position of peak diversity should be considered a fundamental feature of the latitudinal diversity gradient that must be accounted for within attempts to explain the latter’s existence.     

Paleoecology and coalescence: phylogeographic analysis of hypotheses from the fossil record

The application of principles from coalescence theory to genealogical relationships within species can provide insights into the process of diversification and the influence of biogeography on distributional patterns. There are several features that make some organisms more suitable for detailed studies of historical processes; in particular, limited dispersal, which serves to conserve the patterns of genetic variation that developed during colonization. We describe the potential benefits of studies that integrate analyses of genetic variation with information from the fossil pollen record and present recent examples of the application of quantitative methods of phylogeographic analysis.     

Body size of insular carnivores: evidence from the fossil record

Aim Our goals here are to: (1) assess the generality of one aspect of the island rule – the progressive trend towards decrease in size in larger species – for fossil carnivores on islands; (2) offer causal explanations for this pattern and deviations from it – as far as fossil carnivores are concerned; and (3) estimate the speed of this trend. Location Oceanic and oceanic‐like islands world‐wide. Methods Body size estimates of fossil insular carnivores and of their phylogenetically closest mainland relative were obtained from our own data and the published literature. Our dataset consisted of 18 species from nine islands world‐wide. These data were used to test whether the body size of fossil insular carnivores varies as a function of body size of the mainland species in combination with characteristics of the island ecosystem. Results Dwarfism was observed in two canid species. Moderate decrease in body mass was observed in one hyena species. Gigantism was observed in one otter species. Moderate body mass increase was observed in two otter species, one galictine mustelid and perhaps one canid. Negligible or no change in body mass at all was observed in five otter species, three galictine mustelids and one genet. Size changes in teeth do not lag behind in comparison to skeletal elements in the dwarfed canids. The evolutionary speed of dwarfism in a canid lineage is low. Main conclusions Size change in fossil terrestrial insular carnivores was constrained by certain ecological conditions, especially the availability of prey of appropriate body size. When such alternative prey was not available, the carnivores retained their mainland size. The impact of competitive carnivores seems negligible. The case of (semi‐)aquatic carnivores is much less clear. The species that maintained their ancestral body mass may have changed their diet, as is evidenced by their dentition. Among the otters, one case of significant size increase was observed, perhaps best explained as being due to it entering the niche of an obligate aquatic otter. Dwarfism was not observed in otters. The island rule seems to apply to fossil carnivores, but with exceptions. The dependency of the island rule on resource availability is emphasized by the present study.     

The shape of pterosaur evolution: evidence from the fossil record

Abstract Although pterosaurs are a well‐known lineage of Mesozoic flying reptiles, their fossil record and evolutionary dynamics have never been adequately quantified. On the basis of a comprehensive data set of fossil occurrences correlated with taxon‐specific limb measurements, we show that the geological ages of pterosaur specimens closely approximate hypothesized patterns of phylogenetic divergence. Although the fossil record has expanded greatly in recent years, collectorship still approximates a sigmoid curve over time as many more specimens (and thus taxa) still remain undiscovered, yet our data suggest that the pterosaur fossil record is unbiased by sites of exceptional preservation (lagerstätte). This is because as new species are discovered the number of known formations and sites yielding pterosaur fossils has also increased – this would not be expected if the bulk of the record came from just a few exceptional faunas. Pterosaur morphological diversification is, however, strongly age biased: rarefaction analysis shows that peaks of diversity occur in the Late Jurassic and Early Cretaceous correlated with periods of increased limb disparity. In this respect, pterosaurs appear unique amongst flying vertebrates in that their disparity seems to have peaked relatively late in clade history. Comparative analyses also show that there is little evidence that the evolutionary diversification of pterosaurs was in any way constrained by the appearance and radiation of birds.     

Diversification by host switching and dispersal shaped the diversity and distribution of avian malaria parasites in Amazonia

Understanding how pathogens and parasites diversify through time and space is fundamental to predicting emerging infectious diseases. Here, we use biogeographic, coevolutionary and phylogenetic analyses to describe the origin, diversity, and distribution of avian malaria parasites in the most diverse avifauna on Earth. We first performed phylogenetic analyses using the mitochondrial cytochrome b (cyt b) gene to determine relationships among parasite lineages. Then, we estimated divergence times and reconstructed ancestral areas to uncover how landscape evolution has shaped the diversification of Parahaemoproteus and Plasmodium in Amazonia. Finally, we assessed the coevolutionary patterns of diversification in this host–parasite system to determine how coevolution may have influenced the contemporary diversity of avian malaria parasites and their distribution among Amazonian birds. Biogeographic analysis of 324 haemosporidian parasite lineages recovered from 4178 individual birds provided strong evidence that these parasites readily disperse across major Amazonian rivers and this has occurred with increasing frequency over the last five million years. We also recovered many duplication events within areas of endemism in Amazonia. Cophylogenetic analyses of these blood parasites and their avian hosts support a diversification history dominated by host switching. The ability of avian malaria parasites to disperse geographically and shift among avian hosts has played a major role in their radiation and has shaped the current distribution and diversity of these parasites across Amazonia.