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1.
2.
Gorgonian octocorals are among the dominant deep‐sea benthic taxa of many seamounts. Seamount fauna are threatened by destructive fisheries practices, yet little is known about the physical and biological processes that maintain species on seamounts. Few informative molecular markers have been found in deep‐water corals or in gorgonian octocorals. Here we report the characterization of six highly polymorphic microsatellite loci for the deep‐sea precious coral Corallium lauuense from Hawaii using enriched genomic DNA libraries. These loci are being used to examine gene flow and stock structure among seamount and island populations to better understand dispersal and connectivity of seamount species.  相似文献   

3.
Seamounts: centres of endemism or species richness for ophiuroids?   总被引:1,自引:0,他引:1  
Aim To test the hypotheses that seamounts exhibit high rates of endemism and/or species richness compared to surrounding areas of the continental slope and oceanic ridges. Location The south‐west Pacific Ocean from 19–57° S to 143–171° E. Methods Presence/absence museum data were compiled for seamount and non‐seamount areas at depths between 100 and 1500 m for the Ophiuroidea (brittle‐stars), an abundant and speciose group of benthic invertebrates. Large‐scale biogeographical gradients were examined through multivariate analyses at two spatial scales, at the scale of seamounts (< 1° of latitude/longitude) and regions (5–9°). The robustness of these patterns to spatially inconsistent sampling effort was tested using Monte Carlo‐style simulations. Levels of local endemism and species richness over numbers of samples were compared for seamount and non‐seamount areas using linear regressions. Non‐seamount populations were randomly generated from areas and depth ranges that reflected the typical sampling profile of seamounts. Results Seamount ophiuroid assemblages did not exhibit elevated levels of species richness or narrow‐range endemism compared with non‐seamount areas. Seamounts can exhibit high overall species richness for low numbers of samples, particularly on seamounts supporting a dense coral matrix, but this does not increase with additional sampling at the rates found in non‐seamount areas. There were relatively few identifiable seamount specialists. In general, seamount faunas reflected those found at similar depths in surrounding areas, including the continental slope. Seamount and non‐seamount faunas within the study area exhibited congruent latitudinal and bathymetric species turnover. Main conclusions Seamount faunas were variable for ophiuroid faunal composition, species richness and narrow‐range endemism, reflecting their environmental diversity and complex history. The continental slope was also variable, with some areas being particularly species rich. Broad geomorphological habitat categories such as ‘seamounts’ or ‘continental slope’ may be at the wrong scale to be useful for conservation planning.  相似文献   

4.
《Palaeoworld》2016,25(4):519-538
A brachiopod fauna including 15 species belonging to 14 genera is described from a thin carbonate succession of the Lugu Formation at the Anmu section in the northern part of the South Qiangtang Block, which is about 15 km south to the Longmu Co-Shuanghu Suture. The brachiopod fauna is late Kungurian or early Guadalupian in age in terms of the presence of the brachiopod species Vediproductus punctatiformis, “Cryptospiriferomeishanensis, and Paraplicatifera regularis. This is also generally consistent with the age indicated by the fusulines (e.g., Cancellina, Chusenella, Monodiexodina, Nankinella, Neofusulinella, Pseudofusulina, and Sphaerulina) from this formation at the nearby Mari and Duoma A (DMA) sections. Palaeobiogeographically, the brachiopod fauna exhibits a typical Cathaysian affinity and all the species are reported commonly from the equivalents in South China and Cimmerian blocks, which strongly suggest that the South Qiangtang Block had drifted to a position in the warm-water or temperate regime close to South China.  相似文献   

5.
Wen-Zhong Li 《Geobios》2008,41(2):307
The strata below the defined Wuchiapingian-Changhsingian boundary GSSP are mostly covered and obscured by faulting at the Meishan Section D. Therefore, it is very difficult to collect fossils there. After an intensive excavation at Meishan Section C, a diverse fauna based on high-resolution biostratigraphy comprising brachiopods, ammonoids, conodonts, fusulinids and small foraminifers were found. Among these fossils, brachiopods are the most dominant. Eleven species of 10 genera based on more than 1300 specimens are identified. This brachiopod fauna is of late Wuchiapingian-Changhsingian of Lopingian (Late Permian) in age as well constrained by the associated ammonoid Pseudogastrioceras sp., Jinjiangoceras and Konglingites sp., the fusulinid Palaeofusulina and the conodont lineage from C. longicuspidata to C. wangi. In terms of the changes of brachiopod fauna composition around Wuchiapingian-Changhsingian boundary, it clearly indicates a continuous transgression from the upper part of the Lungtan Formation to the lower part of the Changhsing Formation. A new species, Neochonetes (Huangichonetes) meishanensis, is described and some other species are discussed based on the new collection from Meishan Sections C and D.  相似文献   

6.
Holocene lingulid brachiopods are well-known burrowing organisms. Fossil lingulid burrows have been reported from rocks in Europe and North America that range from Ordovician and Devonian through Pennsylvanian. However, the latest authoritative compendium on trace fossils, The Treatise on Invertebrate Paleontology (1975). makes no mention of lingulid burrows. The obvious reason for this omission is that the burrows, although important paleontologically and ichnologically, have never been named formally thereby making it awkward to include them in faunal lists. The monotypic genus Lingulichnites is proposed to remedy this problem. The type specimens are from Upper Devonian rocks in northeastern Ohio.  相似文献   

7.
Until recently, the rhynchonelliform (articulated) brachiopod fauna from the Brazilian continental shelf (western South Atlantic) was represented only by the endemic species Bouchardia rosea (Mawe), reported from coastal waters of the states of São Paulo and Rio de Janeiro. The present study, based on samples from coastal (<30 m), shelf, and continental slope waters (99–485 m), documents the South Atlantic brachiopod fauna and shows that this fauna is more widespread, diverse, and cosmopolitan than previously thought. Based on a total of 16,177 specimens, the following brachiopods have been identified: Bouchardia rosea (Family Bouchardiidae), Platidia anomioides (Family Platidiidae), Argyrotheca cf. cuneata (Family Megathyrididae), and Terebratulina sp. (Family Cancellothyrididae). In coastal settings, the fauna is overwhelmingly dominated by Bouchardia rosea . Rare juvenile (<2 mm) specimens of Argyrotheca cf. cuneata were also found at two shallow-water sites. In shelf settings (100–200 m), the fauna is more diverse and includes Bouchardia rosea , Terebratulina sp., Argyrotheca cf. cuneata , and Platidia anomioides . Notably, Bouchardia rosea was found in waters as deep as 485 m, extending the known bathymetric range of this genus. Also, the record of this brachiopod in waters of the state of Paraná is the southernmost known occurrence of this species. The genera Platidia and Terebratulina are documented here for the first time for the western South Atlantic. The Brazilian brachiopod fauna shares similarities with those from the Atlantic and Indian shelves of southern Africa, and from the Antarctic, Caribbean and Mediterranean waters. The present-day brachiopods of the western South Atlantic are much more cosmopolitan than previously thought and their Cenozoic palaeobiogeographic history has to be reconsidered from that perspective.  相似文献   

8.
The brachiopod fauna of the Chalonnes Limestone (Armorican Massif, France) is famous because of the presence of large, thick-shelled species first described by Oehlert (1881). One of these species originally assigned to Pentamerus davyi Oehlert, 1881 is here revised. External as well as internal characters of the shell allow its attribution to Zdimir robustus (Barrande, 1879), a species from the Trebotov Limestone in the Prague area. This reassignment is consistent with an Upper Emsian age for the Chalonnes Limestone.  相似文献   

9.
The family-group classification of conodonts presented in the revised edition of the Treatise on Invertebrate Paleontology, Part W, Supplement 2, Conodonta, published in 1981, is shown to contain errors with regard to the International Code of Zoological Nomenclature. The classification lacks a concise philosophical and methodological foundation and exhibits very poor conceptualization of the taxa it recognizes. The classification is analyzed and discussed in terms of, among Linnkan taxonomists, generally accepted objectives and conventions with regard to the internal structure and phylogenetic message of a hierarchical natural classification. The obvious errors in terms of the ICZN are pointed out and corrected. As a demonstration of an alternative approach, a classification of the superfamilies Prioniodontacea, Hibbardellacea, and Icriodontacea is presented.  相似文献   

10.
Fish species data from a complex of seamounts off New Zealand termed the "Graveyard Seamount Complex' were analysed to investigate whether fish species composition varied between seamounts. Five seamount features were included in the study, with summit depths ranging from 748-891 m and elevation from 189-352 m. Measures of fish species dominance, rarity, richness, diversity, and similarity were examined. A number of factors were explored to explain variation in species composition, including latitude, water temperature, summit depth, depth at base, elevation, area, slope, and fishing effort. Depth at base and slope relationships were significant with shallow seamounts having high total species richness, and seamounts with a more gradual slope had high mean species richness. Species similarity was modelled and showed that the explanatory variables were driven primarily by summit depth, as well as by the intensity of fishing effort and elevation. The study showed that fish assemblages on seamounts can vary over very small spatial scales, in the order of several km. However, patterns of species similarity and abundance were inconsistent across the seamounts examined, and these results add to a growing literature suggesting that faunal communities on seamounts may be populated from a broad regional species pool, yet show considerable variation on individual seamounts.  相似文献   

11.
A brachiopod fauna including 19 species of 17 genera from an exotic block in the Indus–Tsangpo suture zone in southern Tibet is described and illustrated. The brachiopod fauna is dominated by Martinia elegans and two new taxa: Jinomarginifera lhazeensis gen. et sp. nov. and Zhejiangospirifer giganteus sp. nov. The fauna is closely comparable with those from the middle and upper parts of the Wargal Formation and the Chhidru Formation in the Salt Range of Pakistan, the Chitichun Limestone in southern Tibet, and the Basleo area of West Timor, and these correlations suggest a Wuchiapingian age. The fauna exhibits substantial links with both peri–Gondwanan and Cathaysian faunas, which may imply that it is a seamount biota originally located in the southern margin of the Neotethys during the Late Permian, and was later (in the early Cenozoic) displaced and became sandwiched into younger marine deposits in the collision process between India and Eurasia.  相似文献   

12.
Despite a strong increase in research on seamounts and oceanic islands ecology and biogeography, many basic aspects of their biodiversity are still unknown. In the southwestern Atlantic, the Vitória-Trindade Seamount Chain (VTC) extends ca. 1,200 km offshore the Brazilian continental shelf, from the Vitória seamount to the oceanic islands of Trindade and Martin Vaz. For a long time, most of the biological information available regarded its islands. Our study presents and analyzes an extensive database on the VTC fish biodiversity, built on data compiled from literature and recent scientific expeditions that assessed both shallow to mesophotic environments. A total of 273 species were recorded, 211 of which occur on seamounts and 173 at the islands. New records for seamounts or islands include 191 reef fish species and 64 depth range extensions. The structure of fish assemblages was similar between islands and seamounts, not differing in species geographic distribution, trophic composition, or spawning strategies. Main differences were related to endemism, higher at the islands, and to the number of endangered species, higher at the seamounts. Since unregulated fishing activities are common in the region, and mining activities are expected to drastically increase in the near future (carbonates on seamount summits and metals on slopes), this unique biodiversity needs urgent attention and management.  相似文献   

13.
本文对贵州募役剖面长兴期腕足动物群进行了系统分类鉴定和古生态分析,发现其与前人所报道的华南同时期腕足动物群存在着显著的差别,以Spiriferellina为绝对优势属,包含少量华南长兴期的常见分子,如Fusichonetes、Araxathyris和Peltichia等。募役剖面的腕足类化石主要产自碎屑岩层位,与华南同期碎屑岩相剖面的腕足动物群落相比,该动物群中的优势分子个体较大、壳体较厚且发育较粗大的壳疹,这可能与长兴期募役剖面动物群所处的特殊栖息地环境(浅水碳酸盐岩台地与深水硅质碎屑岩盆地之间的过渡地带)有关。二叠纪末期大规模的火山作用导致水体中碎屑物质含量增加,影响腕足类的滤食效率,而募役剖面清澈、水动力弱的水体环境,为滤食性的腕足动物提供了有利的环境条件。最后,通过与华南长兴期不同沉积相区腕足动物群落(六枝剖面、稻堆山剖面、中寨剖面、新民剖面、马家山剖面和仁村坪剖面群落)的对比分析,发现募役剖面腕足动物群与毗邻的六枝剖面腕足动物群在属级组成上的相似度较高,且过渡岩相栖息地环境下的腕足动物群在生物灭绝事件前也呈现出高优势度、低均匀度的群落结构特征,指示海洋底栖生物群落已经先于二叠纪末期生物集群灭绝事件出现了早期危机信号。  相似文献   

14.
Shu-Zhong Shen  G.R. Shi 《Palaeoworld》2009,18(2-3):152-161
A brachiopod fauna comprising nine species in eight genera from three closely spaced stratigraphic horizons of the same stratigraphic section is described for the first time from the Laibin Limestone in the uppermost part of the Maokou Formation in the Guadalupian/Lopingian (G/L) GSSP section at Penglaitan, Guangxi Autonomous Region, South China. The brachiopod assemblages are bracketed between two conodont zones: Jinogondolella xuanhanensis Zone below and Jinogondolella granti Zone above and, therefore, they can be safely assigned to the latest Capitanian in age. However, all but one of the nine brachiopod species from the Laibin Limestone carry strong early Lopingian (Wuchiapingian) aspect. Thus, the discovery of this brachiopod fauna not only suggests that some Lopingian brachiopod species had already appeared in the late Guadalupian (Capitanian); more importantly, it has also highlighted the fact that both the previously noted pre-Lopingian life crisis (or end-Guadalupian or Middle Permian mass extinction) and Lopingian recovery/radiation actually occurred in late Capitanian times, sometime before the G/L chronostratigraphic boundary. So far, the Penglaitan GSSP section provides the highest-resolution disappearance patterns of different fossil groups around the G/L boundary.  相似文献   

15.
Maastrichtian cephalopods and a brachiopod were dredged from the Butakov, Fedorov, Kotsebu, Il’ichev, Govorov, Gelendzhik, and Ita-Mai-Tai guyots in the Magellan Seamounts. The ammonoids Hypophylloceras sp., Phyllopachiceras sp., Anagaudryceras? sp. A, Anagaudryceras? sp. B, Gaudryceras aff. propemite Marshall, Gaudryceras sp., and Pseudophyllites cf. indra (Forbes), and the single brachiopod Basiliolidae gen. and sp. indet. are a first discovery in this oceanic region, following earlier finds of belemnites (Dimitobelus? sp., Dimitobelidae gen. and sp. nov., and Belemnitella? sp.), and two ammonoid species (Zelandites aff. japonicus Matsumoto and Tetragonitidae gen. and sp. indet.). The Late Cretaceous Magellan Seamounts dimitobelid belemnite fauna shows affinities with southern high latitude forms (New Zealand) and the ammonoid fauna with northern, middle and high latitude ones (Hokkaido-Sakhalin and/or Kamchatka). This suggests by the end of the Cretaceous major surface palaeo-currents from S and N sides in direction of the central Palaeo-Pacific, a position coinciding with the plate tectonic reconstruction of the Magellan Seamounts.  相似文献   

16.
《Comptes Rendus Palevol》2002,1(7):573-585
Brachiopods from the White Chalk of Meudon (Upper Campanian), listed in the catalogue of dˈOrbigny collection, are presented following the revised classification. This is not without difficulty, due to the few specimens found and/or to the heterogeneity of sets listed under the same number and labelled with the same name. The Brachiopod fauna in the Belemnitella mucronata Zone is well represented, considering the Invertebrate fauna as a whole. Two representatives of Craniiformea and about ten species of Rhynchonelliformea, from several superfamilies shared by two orders, are critically described, considering the recent observations and the last works after dˈOrbigny.  相似文献   

17.
18.
Maximum period of existence of endemic genera in the temperately warm-water (subtropical) and temperately cold-water (low boreal and subantarctic) faunal belts is revealed on the base of latest data on the composition of brachiopod fauna of recent seas and oceans and most full data on the paleontological finds of recent brachiopod genera. Most of the subtropical endemics inhabit southern hemisphere; one of them is Bouchardia, which is known beginning with the Late Cretaceous (Maastrichtian), that brings together southern subtropical faunal belt with the tropical zone and suggests that subtropical waters could serve as a refuge for representatives of ancient warm-water faunas during large geological and hydrological reconstructions at the Mesozoic-Cenozoic boundary. Most of the younger endemics of low boreal and subantarctic faunal belts appeared at the Paleogene-Neogene boundary, during the period of formation of modern contrast climate on the Earth that was caused by the formation of Antarctic Circumpolar Current. The appearance of recent species and genera in the Holocene was influenced by last considerable postglacial reconstruction of climate.  相似文献   

19.
《Palaeoworld》2020,29(1):31-46
A new, high-diversity, latest Ordovician brachiopod fauna of nearly 800 brachiopod specimens was collected from the Wanyaoshu Formation (Hirnantian) in the Shaodihe section, Mangshi City, western Yunnan, Southwest China. Altogether 22 genera and two undetermined taxa were identified; dominant are Aegiromena, Anisopleurella, Fardenia, Dalmanella, Hirnantia and Hindella, less common, Paromalomena, Leptaena, Eostropheodonta, Cliftonia, Kinnella, Templeella and Plectothyrella, together with some rare Petrocrania, Xenocrania, Pseudopholidops, Palaeoleptostrophia, Skenidioides, Giraldibella, Draborthis, Dolerorthis and Toxorthis. This is one of the most diverse typical Hirnantia faunas, associated with the Kosov Province. The paleobiogeographic relationships between western Yunnan (Southwest China), Myanmar, Yichang (Central China), Tibet (Southwest China) and Kazakhstan are clarified using Network Analysis and NMDS. The fauna studied is most similar to that of Myanmar; both resided on the Sibumasu terrane. However, the recalculated network diagram, when including the data of Hirnantia fauna from the Prague Basin, indicates that the latter is more closely linked to that of western Yunnan, a testament to the very weak brachiopod provincialism during the Hirnantian, mainly due to the influence of dominant cosmopolitan taxa. Some species of the fauna display significant population variation. Two of the dominant taxa, Aegiromena and Anisopleurella are systematically described, whereas the other two common taxa, Fardenia and Hirnantia are measured and their outlines and internal structures analyzed.  相似文献   

20.
The Late Tremadoc storm-dominated shoreface to inner platform deposits exposed west of the Purmamarca village (Coquena Formation) contain a considerably more diverse brachiopod fauna than previously reported. Coquinite horizons from the lower heterolitic succession have yielded monospecific associations of Nanorthis purmamarcaensis nov. sp. (formerly assigned to N. christianiae KJERULF), which is also reported from the Late Tremadoc rocks of the Cerro San Bernardo area. The fine-grained Upper Member of the Coquena Formation contains a more diverse fauna composed by Nanorthis brachymyaria nov. sp., Astraborthis quebradensis nov. sp. and the new plectorthid genus Lipanorthis (type species L. andinus nov. sp.). A different species of Lipanorthis (L. santalaurae nov. sp.) from the Mid Tremadoc Floresta Formation of the Sierra de Mojotoro is also described.  相似文献   

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