陕西蓝田公王岭“蓝田伟猴”化石的再研究

蓝田公王岭动物群中,唯一的一种非人灵长类化石由胡长康、齐陶(1978)定名为Megamacaca lantianensis(蓝田伟猴)。但按其形态,我们觉得把它归于疣猴亚科比较适宜。特别是与该亚科中的金丝猴属(Rhinopithecus)更为相像,例如蓝田标本下颌支与下颌体垂直,冠状突略向后弯,齿尖起伏较大等都显示了金丝猴的一般性质。至此,本文将蓝田伟猴归于金丝猴属,保留原有种名:Rhinopithecus(Megamacaca)lantianensis(Hu and Qi)。时代为早更新世晚期。     

皖南、赣北奥陶纪笔石立体标本形成环境的初步研究*

皖南、赣东北和赣西北地区奥陶纪笔石地层发育良好,笔石化石丰富。宁国组和胡乐组均为笔石相地层,但笔石的保存特点并不相同。立体保存的黄铁矿化笔石标本主要见于宁国组,而胡乐组的笔石几乎均为薄膜标本。在比较宁国组和胡乐组在岩性、颜色、化石、矿物和元素等方面的特点后发现,两者有较明显的差异。这表明宁国组和胡乐组形成时的环境是不同的,前者为弱还原环境,后者为较强的还原环境,而在研究区内影响笔石体立体保存的主要因素为还原环境和较高的铁含量。在还原环境下,铁可呈Fe~(2+)存在,笔石体内含有硫,死亡后经降解作用可生成H_2S;H_2S和Fe~(2+)结合可使笔石体黄铁矿化,从而使笔石体硬化而呈立体保存下来。宁国组的铁含量明显高于胡乐组,这似可以解释宁国组产有较多笔石立体标本的原因。     

Trigonodus Nieper,1969(牙形刺)属名无效

Nieper(1969)依据澳大利亚 Queenslaad 西部 Nora 组(下奥陶统)的标本以 Trigonodus triangularius Nieper 1969 为模式种,建立了牙形刺新属 Trigonodus. Cooper(1981)将 Nieper 的形式属 Trigonodus 修正为器官属,包括 PM Sa Sb Sc Sd 分子,并将此属的模式种改为 Trigonodus larapintinensis (Crespin, 1943). Cooper 的观点被很多牙形刺专家接受, Trigonodus 属名也被广泛引用在牙形刺文献中 (Stauge, 1984;安泰庠、郑昭昌,1990),     

Ichnology and sedimentology of the early Permian deep-water deposits from the Lercara-Roccapalumba area (Western Sicily,Italy)

Summary Diverse and abundant trace fossils of the deep-waterNereites ichnofacies have been found in well-dated Early Permian deep-water turbidites (Lercara Formation) of western Sicily (Italy). Conodonts indicate a latest Artinskian to Cathedralian (late Early Permian) age. Microfossils (pelagic conodonts, albaillellid Radiolaria, paleopsychrospheric ostracods, foraminiferal associations dominated byBathysiphon), trace fossils (deep-bathyal to abyssalNereites ichnofacies) and sedimentologic data collectively indicate a deep-water environment for the Early Permian turbidites of the Lercara Formation. The dominance ofAgrichnium and of thePaleodictyon subichnogeneraSquamodictyon andMegadictyon suggests that this icnofauna is closely related in ichnotaxonomic composition to other late Paleozoic deep-water ichnofaunas. The occurrence ofAcanthorhaphe. Dendrotichnium andHelicoraphe, to date only reported from Cretaceous or Tertiary flysch deposits, suggests that the entire ichnofauna corresponds well to previously documented Silurian-Tertiary flysch ichnofaunas. Eight new ichnospecies and a new ichnosubgenus,Megadictyon, are described.     

Early Permian facies and paleogeography of the Southeastern Russian craton

Summary During the Early Permian deep-water basins existed in the southeastern part of the Russian craton. North and west of the Cis-Ural foredeep and the Precaspian depression (micro-ocean) carbonate platforms were formed on a shallow-marine shelf during the Asselian, Sakmarian and Early Artinskian. Reefs developed on the margin of these platforms along the slopes of the Cis-Ural foredeep and the Precaspian depression. The reefs shifted platform ward in the eastern areas, due to the tectonic subsidence of the platform margin and at the same time, prograded basinward in the south. Movements of continental blocks from the south during the Late Artinskian and Kungurian caused the separation of the Early Permian basin of the Russian craton from the Palaeo-Tethys, followed by evaporite sedimentation in the restricted basins. The existence of source rocks (bituminous deep-water sediments), thick reservoir rocks (limestones and dolostones), evaporitic seals and structural as well as stratigraphic traps are responsible for large productive gas and oil fields (e.g., Orenburg field), some of which are distinctly associated with reef carbonates.     

Early ordovician reefs from Argentina: Stromatoporoid vs stromatolite origin

Summary Late Arenigian biohermal reef mounds and biostromes within the shallow-marine platform facies of the upper San Juan Formation of the Precordillera (Western Argentina) represent a new Early Ordovician reef type. The meter-sized reefs are dominated byZondarella communis n.g. n. sp. The new taxon is characterized by domical, bulbous and laminar morphotypes exhibiting growth layers and thin horizontal and vertical as well as intermingled skeletal elements included within different sets. The fossil maybe compared with stromatolites and stromatoporoids but an interpretation as primitive stromatoporoids is favoured.     

Stimulation of the Cyclic GMP Pathway by NO Induces Expression of the Immediate Early Genes c-fos and junB in PC12 Cells

Abstract: Stimulation of several second messenger pathways induces the expression of immediate early genes such as c- fos , c- jun , junB , and junD , but little is known about their induction via the stimulation of the cyclic GMP pathway. Here we looked at the expression of early genes in pheochromocytoma PC12 cells after activation of cytosolic guanylate cyclase by sodium nitroprusside. This compound spontaneously releases NO, a molecule known to be involved in cell communication. We found that expression of c- fos and junB but not of c- jun or junD is increased upon activation of cyclic GMP pathway. c- fos mRNA expression was the most activated (fourfold at 30 min), whereas junB response was more modest (2.2-fold activation at 60 min). Nuclear extracts of stimulated cells show increased binding capacity to the AP1 binding site consistent with the dose-response curve. The activating effect of nitroprusside could be reproduced by dipyridamole, a selective cyclic GMP phosphodiesterase inhibitor and by 8- p -chlorophenylthio-cyclic GMP, a permeant selective cyclic GMP-dependent protein kinase activator, and abolished by KT5823, an inhibitor of that kinase. The results show that NO promotes early gene activation and AP1 binding enhancement through the stimulation of the cyclic GMP pathway.     

NEW EARLY JURASSIC ACTINOPTERYGIANS FROM WEIXIN,YUNNAN

PalaeoniscidaeVogt,l852Weixiniscusgen.nov.TypespeeiesWcixiniscusmicrolepis.Genericdiagnovi8Small'palaeoniscidofelongate-fusiformbody.Dorsalfinlong-based,opposingt0thespacebetweenpelvicandanalfins.Pelvicfinwithrela-tivelylongbase,nearertoanalfinthant0pectorals.Caudalfinheterocerca1,deepcleft,upper1obelongerthanlowerlobe-Fin-rays0fallfinscompletelyandsparselysegmented,brancheddistally.Fin-'fulcrapresentontheuppercaudallobe.Postorbitalpartofmaxilliaratherexpanded,ofpalaeoniscoidshape.Suspetis…     

DISCOVERY OF TWO MID-TERTIARY MAMMALIAN FAUNAS FROM HAIYUAN, NINGXIA, CHINA

Inl988-199otheRegionalGeologicalSurveyTeamoftheGeologicalBureauofNingxia(RGSN)foundsomefossilmammalsinthelowerpartoftheHo11g1iugouFormationandtheupperpartoftheOligocene.Inl992ajointteamoflnstituteofVertebratePaleontologyandPaleoanthropo1ogy,AcademiaSinica(IVPP),andtheRGSNwenttoHaiyuailCountyandcollectedmorefossilmamma1sfromtheYuanjia-wowoareausi11gascreen-washingmethodThemammalfaunafromthelowerpartoftheHongliugouFormationiscomposedofAprotodonsp.,Indricotheriidaeindet.,Rhinoceroti…     

Calymenesun granulosa Lu的背壳及接合构造*

描述了Ｃａｌｙｍｅｎｅｓｕｎ ｇｒａｎｕｌｏｓａ Ｌｕ的腹边缘及结合构造,并讨论了此种三叶虫的卷曲机制。认为当其卷曲完善时,尾“边缘“及部分胸肋纳入头颊下,以往描述了尾边缘的部分实际上是尾背结合沟所在位置。卷曲形式为半螺旋卷曲。