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Buchiid bivalves are geographically widespreadin Upper Jurassic and Lower Cretaceousstrata of the Northern Hemisphere. They are oftenabundant and their short stratigraphic rangesmake them ideal biostratigraphic index fossils;these characteristics also render them useful forstudy of evolutionary patterns. We used multivariatemethods to determine if we could discriminatebetween species of Buchia and examinehow morphological characters changethrough time within the genus. Using ten morphologicalcharacters to describe shell shape andsize, we tested for taxonomic differences andmorphologic change in populations of buchiidscollected from a single stratigraphic section onGrassy Island, located along the west coast ofVancouver Island, British Columbia. Morphometricanalysis utilized traditional morphologicalmetrics and techniques, including linearand angular measurements as well as Fourier(outline shape) analyses. Phenetic discriminationrevealed considerable overlap among the recognizedspecies in the morphospace, as well as afairly low discriminatory power between specieswhen compared as a group using a step-wisecanonical variate analysis. Step-wise discriminantanalyses between species pairs gave rise tomuch higher classification rates, suggesting thatdifferent characters are important for distinguishingbetween different species pairs. Ourresults also indicate that single individuals andsmall sample sizes of Buchia specimens are insufficientfor biostratigraphic discrimination(unless other rarely preserved features such asthe hinge and bysuss ear are available) and that anumber of previously described species variantsmay not be taxonomically valid. A biolog usingthe multivariate axis that best discriminates betweenspecies (CV1) and a random walk-basedtest using a Hurst estimate analysis indicate agradualistic evolutionary mode for the Buchiaspecies of Grassy Island. Shell shape and size ofbuchiids do not appear to be closely tied to lithofacieschanges over the c. 10 myr time interval,suggesting that ecophenotypic variation (as itrelates to substrate changes) probably had minimalinfluence on morphology.2008040366摩 洛 哥 早 中 侏 罗 世 Lytoceratid 菊 石 : 古 生 物地 理 与 演 化 意 义 = Early–Middle Jurassic LytoceratidAmmonites with constrictions from Morocco:palaeobiogeographical and evolutionaryimplications. ( 英 文 ). Bourillot R; Neige P; PierreA; Durlet C. Palaeontology, 2008, 51(3):597-609The ammonite genus Alocolytoceras Hyatt,1900 is an uncommon lytoceratid with distinctiveshell ornament. A set of 58 specimens, recentlycollected at Amellago in the central HighAtlas (Morocco), has enabled us to trace a successionof three species over eight biozones fromthe Toarcian to the Aalenian. Two specimensfrom the Lusitanian Basin are added for comparison.Following a review of the genus, basedon original specimens and data from the literature,seven species are considered valid. A palaeobiogeographicalsynthesis of 13 regionsdemonstrates irregular distribution patterns overtime, with a constant presence in the south-westTethys and an instance of rapid diversification ofan endemic fauna in north-west Europe. Ourdata challenge the conventional view that lytoceratidammonite evolution was 'conservative'.2008040367苏 格 兰 Girvan 地 区 晚 奥 陶 世 背 肌 痕 类 软 体 动物 Carcassonnella = The Tergomyan MolluscCarcassonnella from the Upper Ordovician ofGirvan, Scotland. ( 英 文 ). Ebbestad J O. Palaeontology,2008, 51(3): 663-675The tergomyan genus Carcassonnella Hornýand Peel, 1996 is common in and characteristicof the Mediterranean Province in peri-Gondwanan terranes during the late Tremadocand Arenig. It is united with other small, slitbearingcyrtonellids in the CarcassonnellidaeHorný, 1997b, of which Baltiscanella Horný,1997b from the Arenig of the Oslo Region,Norway, and Sarkanella from the Caradoc of theSiljan District, Sweden has been recognized outsidethe Mediterranean Province. The most inclusiveview of the Carcassonnellidae unitesPeelerophon Yochelson, 1982, CarcassonnellaHorný and Peel, 1996, Sarkanella Horný, 1997a,Baltiscanella Horný, 1997b, and TachillanellaHorný, 1997b. Patterns of distribution of generain the family are obscured, however, by widelydifferent phylogenetic relationships presented inthe literature. Here, Carcassonnella multilineata(Reed, 1920) is documented in the upper Whitehouseand Drummuck subgroups of the Girvandistrict, Midland Valley of Scotland, being thefirst record of the genus outside peri-Gondwana.Its enigmatic occurrence on the edge of Laurentiais opposed to the occurrence of low latitudebenthic faunas in higher latitudes during thistime interval (the Boda Event). It is likely, therefore,that the genus spread from the ancient stockfound on the Perunican microcontinent as thisdrifted away from Gondwana in the mid-Caradoc.2008040368奥 地 利 Calcareous 阿 尔 卑 斯 山 东 北 部 瑞 替 期( 晚 三 叠 世 )Monotis ( 双 壳 纲 :Pectinoida) 及 诺 利 期 末 游 泳 动 物 群 危 机 =Rhaetian (Late Triassic) Monotis (Bivalvia:Pectinoida) from the eastern Northern Calcare-116