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A C. Canadian Journal of Earth Sciences, 2008,45(2): 213-229Hundreds of shell borings of different originand displaying variable patterns were found instrophomenide, pentameride, and orthidebrachiopods of five Paleozoic localities in northernand eastern Canada. The borings were analyzedusing simple statistics as well as clusterand nonmetric multidimensional scaling analyses.At the Ordovician Anticosti Island locality,all borings are parasitic or post-mortem in origin,while at the Wenlock-Ludlow Baillie-HamiltonIsland, almost all borings are predatory. At theremaining three localities, borings represent amix of predatory, parasitic, and post-mortemdomichnial borings in all three brachiopod taxa,the proportions of which were controlled largelyby brachiopod shell morphology and paleoecology.For the strophomenides, predatory boringscan be segregated from parasitic and postmortemdomichnial using simple and multivariatestatistical analyses. Sowerbyella-type strophomenideshave a higher proportion of predatoryborings at the Lochkovian localities than atthe Ordovician localities, while the reverse istrue for the Strophomena-type strophomenides.In pentamerides and orthides, very few predatoryborings are identified; most borings were emplacedby parasitic or post-mortem domichnialborers. In pentamerides, this is due to the internalstructure of the shells, which elevated themuscles of the organism above the shell floor,rendering them inaccessible to boring predators.In orthides, more deliberate defense mechanismssuch as toxins or external ornamentation mayhave deterred predation. This study indicates thatthroughout the Paleozoic interactions betweenborers and brachiopods were complex but can beelucidated using a large sample size and statisticalanalyses.2008040035美 国 辛 辛 那 提 地 区 上 奥 陶 统 泥 质 和 介 壳 层 发育 中 的 沉 积 供 给 与 风 暴 漂 选 = Sediment supplyversus storm winnowing in the developmentof muddy and shelly interbeds from the UpperOrdovician of the Cincinnati region, USA. ( 英文 ). Dattilo B F; Brett C E; Tsujita C J; FairhurstR. Canadian Journal of Earth Sciences, 2008,45(2): 243-265Shell-bed development can be a product ofcomplex sedimentological and biological factors.The Upper Ordovician sediments near Cincinnati,Ohio constitute a succession of thinly interbeddedshelly carbonates and mudrocks. Despiteyears of study, the development of Cincinnatianshell beds and metre-scale cycles has, until recently,been attributed solely to storm reworking.This “storm-winnowing model” treats shells aspassive sedimentary clasts, ignoring other factorsof shell-bed development. A recently proposedalternative is Brett and Algeo's idea thatthese shell beds grew during long periods ofnormally low sedimentation, while most mudaccumulated during brief periods of high sedimentation.Under this “episodic starvationmodel,” any storms would winnow pre-existingmuds and shell beds alike. We tested both modelsin the Edenian-Maysvillian (early to midKatian) strata of the Cincinnati region by compilingobservations on their petrologic, taphonomic,and paleoecologic characteristics.The storm-winnowing model does not explainseveral observed features that the episodic starvationmodel does, including (i)storm-relatedsedimentary structures in mudrocks and limestones;(ii) lack of a sufficiently fossiliferousprecursor deposit to winnow; (iii)deep-waterfaunas in grainstones; (iv)mixed taphonomicconditions of shell-bed fossils; (v) ubiquitousdiscontinuity surfaces; (vi)carbonate concretionhorizons; (vii)unwinnowed shell beds; and(viii)micrite in packstones. Episodic starvation isa superior explanation because it explains all ofthese features and allows for the complex interplayof other environmental and biological factorsthat contribute to shell-bed growth. It mayalso be applicable to other deposits, previouslyinterpreted as tempestites.2008040036埃 迪 卡 拉 纪 海 洋 和 动 物 的 协 同 演 化 = On thecoevolution of Ediacaran oceans and animals.( 英 文 ). Shen Y A; Zhang T G; Hoffman P F.proceedings of the National Academy of Sciences,2008, 105(21): 7376-7381 3 图 版 .Fe speciation and S-isotope of pyrite datafrom the terminal Proterozoic Sheepbed Formationin Canada and Doushantuo Formation inChina reveal that ocean deep waters were anoxicafter the global glaciations (snowball Earth) ending635 million years ago, but that marine sulfateconcentrations and inferentially atmosphericoxygen levels were higher than before the glaciations.This supports a long-postulated link betweenoxygen levels and the emergence ofeumetazoa. Subsequent ventilation of the deepocean, inferred from shifts in Fe speciation inNewfoundland (previously published data) andwestern Canada (this report), paved the way forEdiacaran macrobiota to colonize the deep seafloors.2008040037动 物 的 黎 明 : 新 元 古 代 - 寒 武 纪 动 物 化 石 记 录的 演 化 和 古 生 态 模 式 = The dawn of animallife: Evolutionary and palaeoecological patternsin the Neoproterozoic-Cambrian animal fossilrecord. ( 英 文 ). Dornbos S Q; Xiao Shuhai. Pa-12