167 resultados para Brachiopoda


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The global palaeobiogeographic distributions of two resembling genera, Neochonetes and Fusichonetes (Brachiopoda), from the Carboniferous to Griesbachian are analysed. This analysis provides insight into the biotic response of two related genera to changing palaeoclimate, regional tectonics, and environmental crises. Neochonetes originated in the equatorial area in the Mississippian, and it mostly retained this position during the peak of the glaciation in the Carboniferous–Permian ice age (namely in the Pennsylvanian). Neochonetes then dispersed globally during the Cisuralian when the climate became warmer and the ice sheet started to retreat. In the Guadalupian and Lopingian, following the closure of the Ural seaway at the end of the Cisuralian and the regression at the end-Guadalupian, Neochonetes almost disappeared in the western part of Gondwana. Subsequently during the Lopingian the genus retracted to the middle- and low-latitude Palaeo-Tethys and Tethys. In comparison, Fusichonetes originated in the equatorial area in the late Guadalupian and was still present in that area in the Lopingian. Both genera occurred only in South China in the Griesbachian. It is inferred that this could be related, not only to the deteriorated palaeoenvironmental conditions (e.g., anoxia, global warming) leading up to the extinction of most of the Neochonetes and Fusichonetes species in other areas, but also to the better physiological adaptation of the smaller shells of Neochonetes and Fusichonetes species in South China.

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Background: There are many advantages to the application of complete mitochondrial (mt) genomes in the accurate reconstruction of phylogenetic relationships in Metazoa. Although over one thousand metazoan genomes have been sequenced, the taxonomic sampling is highly biased, left with many phyla without a single representative of complete mitochondrial genome. Sipuncula (peanut worms or star worms) is a small taxon of worm-like marine organisms with an uncertain phylogenetic position. In this report, we present the mitochondrial genome sequence of Phascolosoma esculenta, the first complete mitochondrial genome of the phylum. Results: The mitochondrial genome of P. esculenta is 15,494 bp in length. The coding strand consists of 32.1% A, 21.5% C, 13.0% G, and 33.4% T bases (AT = 65.5%; AT skew = -0.019; GC skew = -0.248). It contains thirteen protein-coding genes (PCGs) with 3,709 codons in total, twenty-two transfer RNA genes, two ribosomal RNA genes and a non-coding AT-rich region (AT = 74.2%). All of the 37 identified genes are transcribed from the same DNA strand. Compared with the typical set of metazoan mt genomes, sipunculid lacks trnR but has an additional trnM. Maximum Likelihood and Bayesian analyses of the protein sequences show that Myzostomida, Sipuncula and Annelida (including echiurans and pogonophorans) form a monophyletic group, which supports a closer relationship between Sipuncula and Annelida than with Mollusca, Brachiopoda, and some other lophotrochozoan groups. Conclusion: This is the first report of a complete mitochondrial genome as a representative within the phylum Sipuncula. It shares many more similar features with the four known annelid and one echiuran mtDNAs. Firstly, sipunculans and annelids share quite similar gene order in the mitochondrial genome, with all 37 genes located on the same strand; secondly, phylogenetic analyses based on the concatenated protein sequences also strongly support the sipunculan + annelid clade (including echiurans and pogonophorans). Hence annelid "key-characters" including segmentation may be more labile than previously assumed.

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Mediante buceo y exploraciones al intermareal y submareal de la región Áncash (9°58’08’’S 78°38’34’’W y 10°34’06’’S 77°54’30’’W) entre el 2003 y el 2010 se colectaron, identificaron y fotografiaron 135 especies de invertebrados que corresponden a los grupos Cnidaria (6 especies), Annelida (11 especies), Brachiopoda (1 especie), Mollusca (70 especies), Arthropoda (34 especies), Echinodermata (10 especies), Sipunculida (1 especie) y Chordata (2 especies). Del total de especies, se considera que Sipunculus (Austrosiphon) mundanus representa un nuevo registro para el Perú, que cuatro ampliaron su distribución hacia el norte y nueve hacia el sur. Cada especie se ubica taxonómicamente y se proporciona información de nombre común, diagnosis, hábitat, profundidad, aspectos bioecológicos, distribución geográfica, localidades en la región Áncash, otras localidades en el Perú, comentarios y referencias.

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A comprehensive elemental, isotopic and microstructural analyses was undertaken of brachiopod calcites from the Hamilton Group (Middle Devonian), Clinton Group (Middle Silurian) and Middle to Upper Ordovician strata of Ontario and New York State. The majority of specimens were microstructurally and chemically preserved in a pristine state, although a number of specimens show some degree of post-depositional alteration. Brachiopod calcites from the Hamilton and Clinton Groups were altered by marine derived waters whereas Trenton Group (Middle Ordovician) brachiopods altered in meteorically derived fluids. Analysis of the elemental and isotopic compositions of pristine Hamilton Group brachiopods indicates there are several chemical relationships inherent to brachiopod calcite. Taxonomic differentiation of Mg, Sr and Na contents was evident in three co-occuring species from the Hamilton Group. Mean Mg contents of pristine brachiopods were respectively Athyris spiriferoides (1309ppm), Mucrospirifer mucronatus (1035ppm) and Mediospirifer audacula (789ppm). Similarly, taxonomic differentiation of shell calcite compositions was observed in co-occuring brachiopods from the Clinton Group (Middle Silurian) and the Trenton Group (Middle Ordovician). The taxonomic control of elemental regulation into shell calcite is probably related to the slightly different physiological systems and secretory mechanisms. A relationship was observed in Hamilton Group species between the depth of respective brachiopod communities and their Mg, Sr and Na contents. These elements were depleted in the shell calcites of deeper brachiopods compared to their counterparts in shallower reaches. Apparently shell calcite elemental composition is related to environmental conditions of the depositional setting, which may have controlled the secretory regime, mineral morphology of shell calcite and precipitation rates of each species. Despite the change in Mg, Sr and Na contents between beds and formations in response to environmental conditions, the taxonomic differentiation of shell calcite composition is maintained. Thus, it may be possible to predict relative depth changes in paleoenvironmental reconstructions using brachiopod calcite. This relationship of brachiopod chemistry to depth was also tested within a transgressiveregressive (T-R) cycle in the Rochester Shale Formation (Middle Silurian). Decreasing Mg, Sr and Na contents were observed in the transition from the shallow carbonates of the Irondequoit Formation to the deeper shales of the lowest 2 m of Rochester Shale. However, no isotopic and elemental trends were observed within the entire T-R cycle which suggests that either the water conditions did not change significantly or that the cycle is illusory. A similar relationship was observed between the Fe and Mn chemistries of shell calcite and redox/paleo-oxygen conditions. Hamilton Group brachiopods analysed from deeper areas of the shelf are enriched in Mn and Fe relative to those from shallow zones. The presence of black shales and dysaerobic faunas, during deposition of the Hamilton Group, suggests that the waters of the northern Appalachian Basin were stratified. The deeper brachiopods were marginally positioned above an oxycline and their shell calcites reflect periodic incursions of oxygen depleted water. Furthermore, analysis of Dalmanella from the black shales of the Collingwood Shale (Upper Ordovician) in comparison to those from the carbonates of the Verulam Formation (Middle Ordovician) confirm the relationship of Fe and Mn contents to periodic but not permanent incursions of low oxygen waters. The isotopic compositions of brachiopod calcite found in Hamilton Group (813C; +2.5% 0 to +5.5% 0; 8180 -2.50/00 to -4.00/00) and Clinton Group (813C; +4.00/00 to +6.0; 8180; -1.8% 0 to -3.60/ 00) are heavier than previously reported. Uncorrected paleotemperatures (assuming normal salinity, 0% 0 SMOW and no fractionation effects) derived from these isotopic values suggest that the Clinton sea temperature (Middle Silurian) ranged from 18°C to 28°C and Hamilton seas (Middle Devonian) ranged between 24°C and 29°C. In addition, the isotopic variation of brachiopod shell calcite is significant and is related to environmental conditions. Within a single time-correlative shell bed (the Demissa Bed; Hamilton Group) a positive isotopic shift of 2-2.5% 0 in 013C compositions and a positive shift of 1.0-1.50/00 in 0180 composition of shell calcite is observed, corresponding with a deepening of brachiopod habitats toward the axis of the Appalachian Basin. Moroever, a faunal succession from deeper Ambocoelia dominated brachiopod association to a shallow Tropidoleptus dominated assocation is reflected by isotopic shifts of 1.0-1.50/00. Although, other studies have emphasized the significance of ±20/oo shifts in brachiopod isotopic compositions, the recognition of isotopic variability in brachiopod calcite within single beds and within depositional settings such as the Appalachian Basin has important implications for the interpretation of secular isotopic trends. A significant proportion of the variation observed isotopic distribution during the Paleozoic is related to environmental conditions within the depositional setting.

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Owing to the fact that low-Mg calcite fossil shells are so important in paleoceanographic research, 249 brachiopod, cement and matrix specimens from two neighboring localities (Jemez Springs and Battleship Rock), of the Upper Pennsylvanian Madera Formation were analyzed. Of which, about 86% of the Madera brachiopods are preserved in their pristine mineralogy, microstructure and geochemistry. Cement and matrix samples, in contrast, have been subjected to complete but variable post-deposition~1 alteration. It is confirmed that the stable isotope data of brachiopods are much better than that of matrix material in defining depositional parameters. Because there is no uniform or constant relationship between the two data bases (e.g., from 0.1 to 3.0%0 for 0180 and from 0.2 to 6.7%0 for 013C in this study), it is not possible to make corrections for the matrix data. Regarding the two stratigraphic sections, elemental and petrographic analyses suggest that Jemez Springs is closer to Penasco Uplift than Battleship Rock. Seawater at Jemez Springs is more aerobic, and the water chemistry is more influenced by continental sources than that at Battleship Rock. In addition, there is a relatively stronger dolomitization in the mid-section of the Battleship Rock. Results further suggest that no significant biogenic fractionation or vital effects occurred during their shell secretion, suggesting that the Madera brachiopods incorporated oxygen and carbon isotopes in equilibrium with the ambient seawater. This conclusion is not only drawn from the temporal and spatial analyses, but also supported by brachiopod inter-generic comparison (Composita and Neospirifer) and statistical analysis ( t-test).

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This release of the Catalogue of Life contains contributions from 132 databases with information on 1,352,112 species, 114,069 infraspecific taxa and also includes 928,147 synonyms and 408,689 common names covering the following groups: Viruses • Viruses and Subviral agents from ICTV_MSL UPDATED! Bacteria and Archaea from BIOS Chromista • Chromistan fungi from Species Fungorum Protozoa • Major groups from ITIS Regional, • Ciliates from CilCat, • Polycystines from WoRMS Polycystina UPDATED!, • Protozoan fungi from Species Fungorum and Trichomycetes database • Slime moulds from Nomen.eumycetozoa.com Fungi • Various taxa in whole or in part from CABI Bioservices databases (Species Fungorum, Phyllachorales, Rhytismatales, Saccharomycetes and Zygomycetes databases) and from three other databases covering Xylariaceae, Glomeromycota, Trichomycetes, Dothideomycetes • Lichens from LIAS UPDATED! Plantae (Plants) • Mosses from MOST • Liverworts and hornworts from ELPT • Conifers from Conifer Database • Cycads and 6 flowering plant families from IOPI-GPC, and 99 families from WCSP • Plus individual flowering plants families from AnnonBase, Brassicaceae, ChenoBase, Droseraceae Database, EbenaBase, GCC UPDATED!, ILDIS UPDATED!, LecyPages, LHD, MELnet UPDATED!, RJB Geranium, Solanaceae Source, Umbellifers. Animalia (Animals) • Marine groups from URMO, ITIS Global, Hexacorals, ETI WBD (Euphausiacea), WoRMS: WoRMS Asteroidea UPDATED!, WoRMS Bochusacea UPDATED!, WoRMS Brachiopoda UPDATED!, WoRMS Brachypoda UPDATED!, WoRMS Brachyura UPDATED!, WoRMS Bryozoa UPDATED!, WoRMS Cestoda NEW!, WoRMS Chaetognatha UPDATED!, WoRMS Cumacea UPDATED!, WoRMS Echinoidea UPDATED!, WoRMS Gastrotricha NEW!, WoRMS Gnathostomulida NEW!, WoRMS Holothuroidea UPDATED!, WoRMS Hydrozoa UPDATED!, WoRMS Isopoda UPDATED!, WoRMS Leptostraca UPDATED!, WoRMS Monogenea NEW!, WoRMS Mystacocarida UPDATED!, WoRMS Myxozoa NEW!, WoRMS Nemertea UPDATED!, WoRMS Oligochaeta UPDATED!, WoRMS Ophiuroidea UPDATED!, WoRMS Phoronida UPDATED!, WoRMS Placozoa NEW!, WoRMS Polychaeta UPDATED!, WoRMS Polycystina UPDATED!, WoRMS Porifera UPDATED!, WoRMS Priapulida NEW!, WoRMS Proseriata and Kalyptorhynchia UPDATED!, WoRMS Remipedia UPDATED!, WoRMS Scaphopoda UPDATED!, WoRMS Tanaidacea UPDATED!, WoRMS Tantulocarida UPDATED!, WoRMS Thermosbaenacea UPDATED!, WoRMS Trematoda NEW!, WoRMS Xenoturbellida UPDATED! • Rotifers, mayflies, freshwater hairworms, planarians from FADA databases: FADA Rotifera UPDATED!, FADA Ephemeroptera NEW!, FADA Nematomorpha NEW! & FADA Turbellaria NEW! • Entoprocts, water bears from ITIS Global • Spiders, scorpions, ticks & mites from SpidCat via ITIS UPDATED!, SalticidDB , ITIS Global, TicksBase, SpmWeb BdelloideaBase UPDATED! & Mites GSDs: OlogamasidBase, PhytoseiidBase, RhodacaridBase & TenuipalpidBase • Diplopods, centipedes, pauropods and symphylans from SysMyr UPDATED! & ChiloBase • Dragonflies and damselflies from Odonata database • Stoneflies from PlecopteraSF UPDATED! • Cockroaches from BlattodeaSF UPDATED! • Praying mantids from MantodeaSF UPDATED! • Stick and leaf insects from PhasmidaSF UPDATED! • Grasshoppers, locusts, katydids and crickets from OrthopteraSF UPDATED! • Webspinners from EmbiopteraSF UPDATED! • Bark & parasitic lices from PsocodeaSF NEW! • Some groups of true bugs from ScaleNet, FLOW, COOL, Psyllist, AphidSF UPDATED! , MBB, 3i Cicadellinae, 3i Typhlocybinae, MOWD & CoreoideaSF NEW!• Twisted-wing parasites from Strepsiptera Database UPDATED! • Lacewings, antlions, owlflies, fishflies, dobsonflies & snakeflies from LDL Neuropterida • Some beetle groups from the Scarabs UPDATED!, TITAN, WTaxa & ITIS Global • Fleas from Parhost • Flies, mosquitoes, bots, midges and gnats from Systema Dipterorum, CCW & CIPA • Butterflies and moths from LepIndex UPDATED!, GloBIS (GART) UPDATED!, Tineidae NHM, World Gracillariidae • Bees & wasps from ITIS Bees, Taxapad Ichneumonoidea, UCD, ZOBODAT Vespoidea & HymIS Rhopalosomatidae NEW!• Molluscs from WoRMS Mollusca NEW!, FADA Bivalvia NEW!, MolluscaFW NEW! & AFD (Pulmonata) • Fishes from FishBase UPDATED! • Reptiles from TIGR Reptiles • Amphibians, birds and mammals from ITIS Global PLUS additional species of many groups from ITIS Regional, NZIB and CoL China NEW!

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The present Australian continent was a major component of the north eastern peninsula of Gondwana, itself the southern region of Pangaea, during the Permian period. Surrounding what is now Australia, were additional elements of north eastern Gondwana that are now incorporated into the tectonically complex regions of New Zealand, New Caledonia, the island of New Guinea, Timor, south east Asia, the Himalaya and southern Tibet. India was to the west and south west and Antarctica to the south. Marine water temperatures ranged from cold to temperate and tropical as Permian global climates ameliorated, global surface ocean circulation systems warmed, and due to rifting and northward drifting of some terranes.

Provincialism of global marine faunas was pronounced during the Permian and hence refined biostratigraphical correlations are often fraught with difficulty. The 'middle' Permian stratotypes approved by the International Subcommission on the Permian System have little direct relevance to correlations within the Gondwanan Region at the level of operational biostratigraphical zonal schemes. Brachiopoda are a dominant marine benthonic faunal element of Permian Gondwanan faunas and they provide refined correlations between marine basins within a specific faunal province. Modem faunal provinces are recognised by the distribution patterns of species and genera belonging to a single family or superfamily such as the Papilionoidea within the Insecta. This review provides an example from Permian Brachiopoda, using the distribution data of genera and subgenera of the superfamily Ingelarelloidea, in order to demonstrate the ability to define provinces and their 'Wallace lines' of demarcation between provinces in the geological past.

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A small brachiopod fauna is described from the carbonate rocks of the basal Shazipo Formation of the Baoshan Block, western Yunnan, south-west China, including significant new ventral and dorsal internal morphological features of Cryptospirifer omeishanensis Huang. This fauna is regarded as Wordian (Middle Guadalupian, Middle Permian) because of the presence of Cryptospirifer omeishanensis Huang and associated fusulinids (Neoschwagerina craticulifera Zone). Palaeobiogeographically, the brachiopod fauna is of considerable interest because of its admixed nature characterized by typical warm-water Cathaysian elements intermingled with temperate Peri-Gondwanan taxa. This in turn is interpreted to indicate that the Baoshan Block may have been situated in an intermediate palaeogeographical position between Gondwanaland to the south and Cathaysia to the north during the Mid Permian and, as such, it probably furnished an important 'stepping stone' for the dispersal of Mid Permian eastern Tethyan marine invertebrate taxa (e.g. Cryptospirifer) to the western Tethys.

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A small fauna of 11 species belonging to 10 genera of Permian Brachiopoda from the lower part of the Qubuerga Formation outcropping near Shengmi village in the Qomolangma region of southern Xizang (Tibet) is figured and new taxa are described. New taxa are Quinquenella semiglobosa and Costatumulus shengmiensis. The fauna is most likely of Wuchiapingian (Djhulfian) age as indicated by the majority of the brachiopod species.

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This work presents a systematic study of Permian Brachiopoda from the Sungai Toh Leptodus Shale locality, Pahang State, Peninsular Malaysia. This locality lies within the Central Belt of Peninsular Malaysia, a tectonic unit characterised.by tuffaceous sediments and limestones of Late Palaeozoic age. Two brachiopod-bearing horizons were studied in detail at this locality, the lower one (Horizon 2) bearing a mixed plant and invertebrate assemblage, including the brachiopods Urushtenoidea chaoi (CHING), Leptodus richthofeni KAYSER, Anidanthus cf. sinosus HUANG, Acosarina dorashamensis (SOKOLSKAJA), A. minuta (ABleH) and unidentifiable species of Linoproduetus, Neochonetes, and Strophalosiina. Horizon 3 contains a more abundant and diverse brachiopod fauna, comprising a total. of 57 species representing 47 genera, including Vediproductus punetatiformis (CHAO), Permianella typica HE & ZHU, Tranrennatia gratiosa (WAAGEN), Leptodus richthofeni KAYSER, Leptodus cf. tenuis (WAAGEN) and "Semibrachythyrina" [= Alphaneospirifer] cf. pyramidiformis LIANG. It is
suggested in this study that the age of the Sungai Toh locality is Capitanian (late Guadalupian) to possibly Wuchiapingian (early Lopingian),
as it appears to correlate well with the Lengwu fauna from Zhejiang in eastern China. The palaeobiogeographical affinities of the Sungai Toh fauna are interesting, mainly indicating strong Palaeo-equatorial affinities, while there are also some elements more typical of the cooler periGondwana
Region.

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Spatial and temporal variations in biological diversity are critical in understanding the role of biogeographical regulation (if any) on mass extinctions. An analysis based on a latest database of the stratigraphic ranges of 89 Permian brachiopod families, 422 genera, and 2059 species within the Boreal, Paleoequatorial, and Gondwanan Realms in the Asian–western Pacific region suggests two discrete mass extinctions, each possibly with different causes. Using species/family rarefaction analysis, we constructed diversity curves for late Artinskian–Kungurian, Roadian–Wordian, Capitanian, and Wuchiapingian intervals for filtering out uneven sampling intensities. The end-Changhsingian (latest Permian) extinction eliminated 87–90% of genera and 94–96% of species of Brachiopoda. The timing of the end-Changhsingian extinction of brachiopods in the carbonate settings of South China and southern Tibet indicates that brachiopods suffered a rapid extinction within a short interval just below the Permian/Triassic boundary.

In comparison, the end-Guadalupian/late Guadalupian extinction is less profound and varies temporally in different realms. Brachiopods in the western Pacific sector of the Boreal Realm nearly disappeared by the end-Guadalupian but experienced a relatively long-term press extinction spanning the entire Guadalupian in the Gondwanan Realm. The end-Guadalupian brachiopod diversity fall is not well reflected at the timescale used here in the Paleoequatorial Realm because the life-depleted early Wuchiapingian was overlapped by a rapid radiation phase in the late Wuchiapingian. The Guadalupian fall appears to be related to the dramatic reduction of habitat area for the brachiopods, which itself is associated with the withdrawal of seawater from continental Pangea and the closure of the Sino-Mongolian seaway by the and-Guadalupian.

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Two marginiferinid species, Marginifera spinulifera sp. nov. and Transennatia sulcata sp. nov. are described from the Early Permian Liangshan and lowermost Chihsia formations at the Chuanmu Section, Sichuan, China. The Linshuichonetes – Crurithyris Community is discussed in the context of a pioneering opportunistic community that developed at the onset of the Yanghsingian transgression in the late Artinskian. This community was characterized by species that were generally small and relatively thin-shelled, and showed other features that are ecological adaptations to fluctuating environmental conditions.

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A small collection of brachiopods is described from the lower Middle Permian Yanchibeishan Formation of the Dongujimqinqi area, eastern Inner Mongolia, China. This fauna consists of the following four species: Kochiproductus sp., Linoproductus simensis (Tschernyschew), Rhynchopora inconstantis Lee and Gu and Licharewia grewingki (Netschajew). The Dongujimqinqi fauna exhibits a strong Boreal-type aspect and suggests an early Middle Permian in age.

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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.

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This paper describes fourteen brachiopod species in eleven genera from the Late Permian Wuchiapingian Coal Series (Lungtan Formation) of South China. Of these, the shell bed fauna from the basal Lungtan Formation is interpreted to represent the onset of the recovery of shelly faunas in the aftermath of the Guadalupian/Lopingian (G/L) mass extinction in South China. The post-extinction brachiopod faunas in the Wuchiapingian are characterized by the presence of numerous Lazarus taxa, survivors, and newly originating taxa. These elements capable of adapting their life habits were relatively more resistant to the G/L crisis. The post-extinction faunas, including survivors and the elements originating in the recovery period, have no life habit preference, but they were all adapted to a variety of newly vacated niches in the Late Permian oceans. Two new species, Meekella beipeiensis and Niutoushania chongqingensis, are described, and two Chinese genera, Niutoushania and Chengxianoproductus, are emended based on re-examination of the type specimens and new topotype materials from the Lungtan Formation.