Palynology and age of the Early Oligocene units in Çardak-Tokça Basin, Southwest Anatolia: Paleoecological implications

In this study, the lignite bearing sediments of Çardak-Tokça basin exposed in southwest Anatolia, were palynologically examined. A well preserved and diverse palynomorph assemblage indicating an Early Oligocene age was recovered from the Hayrettin and Tokça formations. The palynomorph assemblage is dominated by Pinus, Sparganiaceae, Juglandaceae and diverse tricolpate and tricolporate pollen. In addition a few species of marine dinoflagellate cysts were encountered as well. The Early Oligocene age is based primarily on the presence of stratigraphic markers such as: Boehlensipollis hohli, Slowakipollis hippophaëoides, Aglaoreidia cyclops, Dicolpopollis kockeli, Compositoipollenites rhizophorus ssp. burghasungensis, Mediocolpopollis compactus ssp. ellenhausensis, Pentapollenites pentangulus, Subtriporopollenites simplex and Intratriporopollenites instructus. Palynological data indicate a humid subtropical climatic conditions during the deposition of the Çardak-Tokça sediments. Ecological analysis of the palynomorph assemblage identifies several paleo-associations of montana, lowland and slope, swamp and water-edge and freshwater aquatic elements. In this study, Çardak-Tokça, Çank?r?-Çorum, Thrace and southwest Anatolian molasse basins (Kale-Tavas and Denizli) were correlated in accordance with their palynostratigraphic content and the results show that the deposition took place during the Early Oligocene in the Çardak-Tokça basin. This basin is older than Thrace basin and southwest Anatolian molasse basins (Kale-Tavas and Denizli molasse) which were deposited during the Late Oligocene-Early Miocene.     

Mobergellans (Problematica) from the Cambrian of Greenland, Siberia and Kazakhstan

Mobergellans are disc-shaped problematic fossils of phosphatic composition bearing prominent muscle attachment structures on the presumed internal surface. They are found exclusively in sediments of Early Cambrian age, mainly from Laurentia, Baltica and Siberia. Type material ofDiscinella brastadi Poulsen, 1932 from North-East Greenland is re-studied and synonomised withDiscinella micans (Billings, 1871). Specimens from Siberia described asD. brastadi are re-assigned toMobergella hexactina n. sp., and specimens from Siberia described asMobergella radiolata Bengtson, 1968 are re-assigned toM. sibirica n. sp.Aktugaia triangula Mis-Sarzhevsky, 1976 from Kazakhstan is redescribed, and its relationship to other mobergellans is discussed.      

江苏句容中生代晚期中华鳞齿鱼属(Sinolepidotus)一新种,兼论该属的系统位置

记述了在江苏句容发现的中华鳞齿鱼属(Sinolepidotus)一新种——长背鳍中华鳞齿鱼(Sinolepidotus longidorsalis sp.nov)。新种的一般形态特征如身体高纺锤形,背鳍长,臀鳍离尾鳍近,头骨外部骨片的形状及排列格局,口裂小,下颌骨有较高的冠状突,口缘牙齿高而尖,体侧中部和背区的一些鳞片高显著大于宽等,与浙江早白垩世的浙江中华鳞齿鱼(Sinolepidotus chekiangensis)很相似。但新种具有背鳍较长,背鳍鳍条数目较多,吻突尖,及鳞片后缘梳状齿不发育等特征区别于浙江中华鳞齿鱼。此外,评论了中华鳞齿鱼属的系统位置,认为它的形态特征与Paralepidotus很相似,对它原列入半椎鱼科提出疑问。根据长背鳍中华鳞齿鱼的性质并参考有关地质古生物资料,将含鱼层杨冲组的时代定为早白垩世。     

1,10-Phenanthroline-5,6-dione as a building block for the synthesis of homo- and heterometallic complexes

1,10-Phenanthroline-5,6-dione (C₁₂H₆N₂O₂ (1)) reacts with V(η⁶-mesitylene)₂ and Ti(η⁶-toluene)₂ affording coordination compounds of general formula M(O,O′---C₁₂H₆N₂O₂)₃ (M=Ti (2); M=V (3)) which further react with TiCl₄ or TiCp₂(CO)₂ yielding the tetrametallic species M(O,O′---C₁₂H₆N₂O₂---N,N′)₃(M′L_n)₃ (M=V, M′L_n=TiCl₄ (4); M=Ti, M′L_n=TiCp₂ (5); M=V, M′L_n=TiCp₂ (6)). The complex salt [Fe(N,N′---C₁₂H₆N₂O₂)₃][PF₆]₂ (7) has been obtained from iron(II) chloride tetrahydrate and 1 in the presence of NH₄PF₆. The reaction of 7 with TiCp₂(CO)₂ affords the tetrametallic derivative [Fe(N,N′---C₁₂H₆N₂O₂---O,O′)₃(TiCp₂)₃][PF₆]₂ (8). TiCl₂(THF)₂ reacts with MCp₂(O,O′---C₁₂H₆N₂O₂) to give MCp₂(O,O′---C₁₂H₆N₂O₂---N,N′)TiCl₂ (M=Ti (9); M=V (10)). By reaction of TiCp₂(O,O′---C₁₂H₆N₂O₂---N,N′)TiCl₂ (9) with C₁₂H₆N₂O₂, the bimetallic derivative TiCp₂(O,O′---C₁₂H₆N₂O₂---N,N′)TiCl₂(O,O′---C₁₂H₆N₂O₂) (11) has been prepared, which readily adds to TiCl₄, to give the trimetallic titanium derivative TiCp₂(O,O′---C₁₂H₆N₂O₂---N,N′)TiCl₂(O,O′---C₁₂H₆N₂O₂---N,N′)TiCl₄ (12). VCp₂(O,O′---C₁₂H₆N₂O₂---N,N′)TiCl₂ (10) reacts with the tris-chelate iron(II) cation 7 affording the heptametallic cationic complex [Fe(N,N′---C₁₂H₆N₂O₂---O,O′)TiCl₂(N,N′---C₁₂H₆N₂O₂---O,O′)VCp₂]₃ ⁺² isolated as the hexafluorophosphate 13.     

Victims of the Early Toarcian anoxic event: the radiation and extinction of Jurassic Koninckinidae (Brachiopoda)

The significant mass extinction attributed to the Early Toarcian anoxic event had a severe impact on the phylum Brachiopoda. Beyond a serious decrease of species diversity, the extinction of the orders Spiriferidina and Athyridida is connected with this episode. The order Athyridida was represented by the family Koninckinidae in the Early Jurassic. The stratigraphical and geographical distribution of the three Early Jurassic koninckinid genera ( Koninckella, Koninckodonta, Amphiclinodonta ) shows a definite radiative pattern. The number of their nominal species increased from 2 to 17 from the Sinemurian to Early Toarcian; in the same time interval, their area increased from the Alpine region to the whole Mediterranean and the NW-European domains. This radiative evolution can be explained as the result of different factors: (1) morphological adaptation to muddy bottoms, (2) fundamental changes in the current pattern in the Tethys/Laurasian Seaway, and, possibly, (3) utilization of methane-based chemosynthesis as alternative food source. The radiation of koninckinids, leading from the cryptic habitats of the Tethyan rocky floors to the extensive muddy bottoms of the open European shelves, was abruptly terminated by the anoxic event in the Early Toarcian Falciferum Zone. The main causes of the extinction might be: (1) the excessive warming of Tethyan deep waters by thermohaline circulation, (2) the anoxic event, which was not survived by the spire-bearers, handicapped by their stiff, calcareous spiralia. Brachiopoda, Early Jurassic, Europe, extinction, Koninckinidae, radiation, Tethys.     

龙凤山藻在澄江早寒武世生物群中的发现

主要报道了产自云南昆明海口耳材村早寒武世筇竹寺组玉案山段澄江生物群中可能为漂浮生长的宏观藻类化石-心型龙凤山藻（新种）（Longfengshania cordata sp.nov.)和中华豆芽藻（新属、新种）（lantulaformis sinensis gen.et sp.nov)。这些化石的发现进一步显示了澄江生物群种物多样性,为揭示该生物群爆发性演化提供了新的证据。通过对龙凤山藻属亲缘关系的深入比较研究,进一步证明该类化石应归属宏观藻类以及它们遗传上的稳定性、演化上的保守性和环境上的适应性。     

北京京西盆地早白垩世同翅目化石一新属(同翅目:蜡蝉总科)

记述了北京京西盆地早白垩世卢尚坟组同翅目一新属新种翅痣白恶蜡蝉Cretocixius stigmatosus gen.et sp.nov,化石采自卢尚坟组昆虫的典型产地卢尚坟村,时代属早白垩世巴列姆期（Barremian Stage),归卢尚坟昆虫群;在分类上属蜡蝉总科拉蜡蝉科。模式标本保存于北京林业大学。     

Frenelopsis (Coniferales: Cheirolepidiaceae) And Related Male Organ Genera From The Lower Cretaceous Of Spain

Vegetative plant remains and microsporangiate cones, related to the fossil genera Frenelopsis and Classostrobus respectively, were studied in three localities from the Lower Cretaceous of the Pyrenees and Iberian Ranges (Spain). Sterile remains belong to three different species: F. Rubiesensis Barale, F. Ugnaensis sp. nov. and F. Turolensis sp. nov. The male cones Classostrobus ugnaensis sp. nov. and C. Turolensis sp. nov. are associated with the two latter species respectively, and C. Turolensis is found in connection with F. Turolensis . Internodes of F. Ugnaensis display small hemispherical papillae and long conical hairs covering the entire cuticle surface, while F. Turolensis has a strip of hairs near the leaf margin, in addition to more massive outer stomatal papillae and higher stomatal density. The tiny cones of C. Ugnaensis bear microsporophyll cuticles capped with vermiculate flattened papillae and a fringe of marginal hairs, while C. Turolensis has a central area of microsporophylls covered by long conical hairs. Sedimentological and taphonomic analyses show that the assemblages studied belong to a wide spectrum of habitats. These indicate that Spanish Lower Cretaceous frenelopsids were xeromorphic plants, able to adapt to helophytic and riparian habitats, and grew in brackish coastal marshes and fluvio–lacustrine freshwater environments.     

A diatom-based reconstruction of Early Holocene hydrographic and climatic change in a southwest Greenland fjord

A diatom-based reconstruction of surface-water paleoclimatic and paleoceanographic changes in Ameralik Fjord, southwest Greenland, is presented for the Holocene interval 8800 to 3600 cal yrs B.P. A minor episode of cold surface-water conditions is found at ca. 8000–7800 cal yrs B.P. This may be due to the local conditions in the fjord and linked to the culmination of a strong melt-water outflow rather than reflecting the widespread North Atlantic (8.2 ka) cooling event. Warming of surface-water condition from 7800 to 7100 cal yrs B.P., probably corresponding to the early and warmest part of the Holocene Thermal Maximum (HTM) in this region, is reflected in the diatom assemblages and supported by other proxies. The West Greenland Current (WGC) influences the fjord strongly during this interval, indicating enhanced advection of Atlantic water-masses derived from the Irminger Current (IC). A major sedimentary change with a hiatus between 6800 and 4400 cal yrs B.P. prevents a reconstruction of mid-Holocene paleoceanograpy. The final and less prominent part of the HTM is found after 4400 cal yrs B.P. Previous studies from the same site have shown this final stage of the HTM to end at 3200 cal yrs B.P. with the onset of the ‘Neoglaciation’. Our study provides further evidence that the marine sedimentary record from West Greenland fjords yields paleoenvironmental information reflecting a significant link between local and large scale North Atlantic oceanographic and climatic changes.     

Male spike strobiles with Gnetum affinity from the Early Cretaceous in western Liaoning,Northeast China

A fossil with Gnetum affinity was found in the Jianshangou Member （Barremian Age） of the Yixian Formation （Lower Cretaceous Epoch） of the Jehol Group in western Liaoning, northeastern China. The single fossil specimen is represented by both elongate-cylindrical male spike strobiles which borne within a nodal bract of cauliflorous branch. The spike strobiles have apparent nodes, invisible internodes, and numerous verticillate involucral collars. The microsporangiate units within involucral collars are not seen. The male spike strobiles with verticillate involucral collars occur exclusively in Gnetum; hence, the fossil strobiles are attributed to a new taxon, Khitania columnispicata gen. ＆ sp. nov., being closely related to Gnetum. The general isotopic dating suggests an age of Barremian, ca. 125-122 million years （Myr） ago for the Jianshangou Member. The palaeoecological and palaeoclimatic inference based on the compositions of flora and fauna, and lithological characters of the fossil locality suggests that the fossil plants grew in a subtropical mesophytic forest and under a warmer climate. The remains of male spike strobiles are the first record of gnetalean macrofossil. It documents the evolution of the distinct gnetoid morphology and indicates a wider range of distribution of Gnetaceae in the Early Cretaceous than present day.