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applied estimates of shell repair frequencies involvesdivision of the number of individualswith at least one scar by the total number of individualsin the sample (the Individuals withscars method). Using this calculation, 207specimens of Lophospira trilineata Ulrich andScofield yielded a shell repair frequency of 4.8%;in 28specimens of Trochonemella sp. the shellrepair frequency was 35.7%. Repairs in Trochonemellaoccur primarily in the larger size class,suggesting that a size refuge was achieved bythis species. Low repair frequencies in L. trilineatasuggest predation with a higher successrate or fewer encounters. This study demonstratesthat the paradigm of a standardized lowlevel of shell repair in Ordovician and Siluriangastropods is oversimplistic and a range of frequencyrates can be expected.2008040363加 拿 大 不 列 颠 哥 伦 比 亚 省 Taseko 湖 晚 赫 塘 期( 早 侏 罗 世 ) 菊 石 动 物 = Late Hettangian(Early Jurassic) Ammonites from Taseko lakes,British Columbia, Canada. ( 英 文 ). Longridge L;Smith P L; Tipper H W. Palaeontology, 2008,51(2): 367-404The Taseko Lakes area yields the most diverseand well-preserved late Hettangian ammoniteassemblage in British Columbia. In total, 27ammonite taxa are described, of which Fergusoniteshendersonae, Eolytoceras constrictum andPseudaetomoceras victoriense are new. Basedon this study, Phylloceras cf. asperaense Hillebrandt,Togaticeras togatum (Neumayr), T. aff.goisernense Rakús, Eolytoceras aff. guexi Taylor,Discamphiceras aff. silberlingi Guex,Schlotheimia cf. cuevitensis Hillebrandt andFranziceras aff. graylockense Taylor are newlyrecognized in the North American MineralenseZone whereas Nevadaphyllites psilomorphus(Neumayr), N. aff. compressus Guex, Fergusoniteshendersonae sp. nov., Eolytoceras chongiHillebrandt, E. constrictum sp. nov., Paracalocerasspp. A and B, P.? spp., Metophioceras? sp.and Schreinbachites? aff. laqueoides (Hyatt) arenewly recognized in the Rursicostatum Zone.Discamphiceras silberlingi, D. sp. nov., Alsatitesaff. bipartitus (Hillebrandt), Alsatites sp., Pseudaetomocerasvictoriense sp. nov. and Paracalocerasaff. varaense Hillebrandt are newlyrecognized in both the Mineralense and Rursicostatumzones. The Taseko Lakes fauna allowsclear correlations with contemporaneous strata inother areas of North America as well as with theCanadensis Zone and probably the Arcuatumhorizon of the South American succession.Broad correlations are also possible with Hettangianor lowest Sinemurian strata in New Zealandand the eastern Tethys. Furthermore, theTaseko Lakes fauna permits correlation of theMineralense and Rursicostatum zones with thecircum-Mediterranean Marmoreum Zone. Finally,this fauna suggests that the MineralenseZone and the lower to middle portion of the RursicostatumZone in Taseko Lakes are equivalentto the Complanata Subzone whereas the upperportion of the Rursicostatum Zone correlateswith the Depressa Subzone of the north-westEuropean Angulata Zone.2008040364关 于 早 期 牡 蛎 演 化 的 问 题 : 答 复 Márquez-Aliaga 和 Hautmann = Problems concerningearly oyster evolution: A reply to Márquez-Aliaga and Hautmann. ( 英 文 ). Malchus N. PalaeogeographyPalaeoclimatology Palaeoecology,2008, 258(1-2): 130-134The reconstruction of early oyster phylogenyis hampered by multiple convergent, parallel (orboth) shell-character evolution outside andwithin the Ostreoidea and by poor knowledge ofcharacter distribution. This contribution brieflydiscusses the extent of the problem with referenceto controversial lines of arguments in twoprevious contributions concerning the alivincularligament, antimarginal ribs or plicae, shell mineralogyand microstructures, Quenstedt musclescar versus dorsal radial mantle retractor scars,amphi-pleurothetic cementation versus leftpleurotheticbyssal attachment or free recliningmode, and the convex versus concave resiliumsupport in the right valve of oysters. A preliminarycladistic analysis suggests that neither Gryphaeanor Enantiostreon derive from alivincular,crossed-lamellar taxa (Pseudomonotidae andProspondylidae, respectively). Triassic plicateEnantiostreon, Umbrostrea, and a palaeolophidspecies appear in a basal position withinOstreoidea s.l., but none of them appears to bedirectly related to Recent Lophinae, a result thatis consistent with numerous genetic analyses thatplace Lophinae in a terminal position rather thanclose to the root. The present data suggest thatOstreoidea s.l. (including Triassic plicate taxa)derive from a single, as yet unidentified stemgroup but that Ostreoidea s.l. is not necessarilymonophyletic in a strict sense.2008040365加 拿 大 大 不 列 颠 哥 伦 比 亚 Grassy 岛 上 侏 罗统 - 下 白 垩 统 地 层 中 Buchia ( 双 壳 纲 :Buchiidae) 种 的 鉴 别 和 演 化 模 式 = Speciesdiscrimination and evolutionary mode of Buchia(Bivalvia: Buchiidae) from Upper Jurassic–Lower Cretaceous strata of Grassy Island, BritishColumbia, Canada. ( 英 文 ). Grey M; HaggartJ W; Smith P L. Palaeontology, 2008, 51(3):583-595115