Androecium of Archaefructus , the Late Jurassic Angiosperms from Western Liaoning, China

ＩｎｔｒｏｄｕｃｔｉｏｎＡｒｃｈａｅｆｒｕｃｔｕｓ ,ｔｈｅｏｌｄｅｓｔｋｎｏｗｎａｎｇｉｏｓｐｅｒｍｓ ,ｗｅｒｅｆｏｕｎｄｆｒｏｍｔｈｅＵｐｐｅｒＪｕｒａｓｓｉｃＪｉａｎｓｈａｎｇｏｕＦｏｒｍａｔｉｏｎ (ｉ.ｅ .ｔｈｅｆｏｒｍｅｒｌｏｗｅｒｐａｒｔｏｆＹｉ     

Androecium of Archaefructus,the Late Jurassic Angioperms from Western Liaoning,China

Androecium of the earliest known flowering plant Archaefructus liaoningensis was found from the Upper Jurassic Jianshangou Formation of western Liaoning, China. The androecium consists of numerous stamens bearing in pair on the re-productive axes below conduplicate carpels. The stamens are composed of a short filament and basifixed anther for each. Mo-nosulcate pollen in situ are found from the anthers. The characters of the androecium reveals that Archaefructus are probably protandrous, and the paired stamens and monosulcate pollen appear to indicate that Archaefructus, as primitive angiosperms, might be derived from extinct seed-ferns during the Older Mesozoic. Archaefructus is considered Late Jurassic in age.     

Anomozamites (Bennettitales) from Middle Jurassic Haifanggou Formation,western Liaoning,China

The Middle Jurassic Hangfanggou Formation is well exposed in Shangsanjiao and Xiasanjiao villages area,Baimashi town of Huludao,western Liaoning,China.Recently,abundant fossil plants were collected from the Hangfanggou Formation.One new species,Anomozamites sanjiaocunensis sp.nov.(Bennettitales),is described in this study.This is the first report of the genus Anomozamites from the Haifanggou Formation based upon the leaf morphology and epidermal structures.The discovery of the new species extends significantly the stratigraphic and geographic distribution of Anomozamites in the Middle Jurassic.It also shows that Anomozamites was a common member of Bennettitales once lived in the Middle Jurassic warm temperate region.The new species also improves the knowledge on understanding the leaf morphology,epidermal features and the diversity of Anomozamites during the Middle Jurassic.The epidermal characters of the new species and its associated plants reveal that the plants grew in a warm and moderately humid environment in the warm temperate zone.The presence of some deciduous plants,such as ginkgoaleans,czekanowskialeans and conifers,indicate the climate with seasonal fluctuations in temperature.     

A new pterosaur (Pterosauria) from Middle Jurassic Tiaojishan Formation of western Liaoning,China

A new pterosaur Archaeoistiodactylus linglongtaensis gen.et sp.nov.is erected based on an incomplete skeleton with a partial skull and lower jaw.The new taxon is characterized by circular tooth sockets of anterior mandibular teeth,the anterior teeth of the upper jaw bearing posteriorly directed crowns,a relatively short metacarpus,and wing phalanges 2 and 3 and the tibia subequal in length.It possesses some plesiomorphic characters such as short metacarpals and circular tooth sockets.The pointed jaw tip present in the new taxon indicates that the expanded jaw tips of later istiodactylids are a derived character state,and the new taxon represents the first istiodactylus-like pterosaur found from the pre-Late Jurassic deposits,which provides a key role in our understanding the origin and evolution of the known istiodactylid pterosaurs.Archaeoistiodactylus is regarded as the ancestor form of the known istiodactylid pterosaur.     

Changes of taxonomical composition of Late Jurassic Early Cretaceous palynofloras of Bureya Basin,Russia

The changes of taxonomical composition of the Late Jurassic-Early Cretaceous palynofloras are revealed,in the upper stream of Bureya River in Bureya Basin.The palynofloras are dominated as follows:the Berriasian one by ferns (Cyatheaceae,Dicksoniaceae,Osmundaceae), Classopollis and bisaccate pollen;the Valanginian-Hauterivian one by ferns (Cyatheaceae,Dicksoniaceae), Ginkgocycadophytus and bisaccate pollen;the Barremian one by ferns(Cyatheaceae,Dieksoniaceae);the Aptian one by ferns(Cyatheaceae,Dieksoniaceae,Gleicheniaceae)and Ginkgocycadophytus;and the Albian one by ferns(Schizaeaceae)and bisaccate pollen.In the Albian the floral diversity raises with the angiosperms appearing.     

U-Pb-Hf isotopes and petrogenesis of Late Jurassic akakitic quartz monzodiorite in Xingcheng area,western Liaoning Province

The petrogenesis and geodynamic setting of the Late Jurassic Baita porphyry quartz monzodiorite in Xingcheng--Liaoxi area provide information for understanding the Mesozoic tectonic evolution of the northeastern North China Craton. In this paper, geochronological, whole-rock geochemical, and in-situ zircon Hf isotopic analyses of Baita porphyry quartz monzodiorite were investigated to constrain the crystallization age and petrogenesis. Zircons exhibit typical oscillatory zoning in cathodoluminescence images and show relatively high Th/U ratios(0.78--1.62), and U-Pb analyses indicate that these rocks were crystallized during the Late Jurassic(159±1 Ma). Geochemically, they are characterized by high contents of SiO_2(65.21 wt%--65.31 wt%), Al_2O_3(16.29 wt%--16.31 wt%), Sr(521×10~(-6)-539×10~(-6)), and Sr/Y ratio(45.1--47.8) but low Y(10.9×10~(-6)-12.0×10~(-6)), with obvious adakitic geochemical affinities. These above-mentioned findings, combined with their negative ε_(Hf)(t) values(-21.7 to-20.2), corresponding two-stage model age(T_(DM2)) of 2 579--2 484 Ma, as well as low MgO(1.38 wt%--1.39 wt%), Cr(18.5×10~(-6)-19.5×10~(-6)) and Ni(9.45×10~(-6)-9.46×10~(-6)) values, indicate that Baita porphyry quartz monzodiorite may be generated by partial melting of the Neoarchean-Paleoproterozoic thickened basaltic lower crust. Based on the results from this study and pre-vious regional studies, it is concluded that Baita porphyry quartz monzodiorite was spatially related to the westward subduction of the Paleo-Pacific plate.     

Comparison of Early Jurassic flora from South Primorye of Russia with its main coeval floras of China

The Early Jurassic flora,with over 42 species of 26 genera and documented in age by sandwiched marine beds,from the Lower Jurassic Schitukhe Formation of South Primorye,Russia,is further reported.The flora is dominated by cycadophytes,ferns and conifers,with some of ginkgoales and czekanowskiales,and characterized by occurrence of Cycadocarpidium,with very rare Coniopteris.A comparison of this flora with its coeval Early Jurassic floras of China is discussed.The Russian flora is considered as the early assemblage of Early Jurassic flora,and more similar to the Early Jurassic floras from the Shansonggang-and Yihe formations of Jilin,Beipiao Formation of Liaoning,and lower-middle Guanyintan Formation of Hunan in China.     

Early Jurassic Flora and Stratigraphy from Shansonggang of Southern Jilin,China

More than 35 species belonging to 22 genera of fossil plants are recognized by the authors from the Shansonggang flora in the 8hansonggang Basin of Jilin, China. Among them, the coexistence of Coniopteris and Cycadocarpidium demonstrates that the present flora possesses the characters of the early assemblage of Early Jurassic floras in Eurasia. Therefore, the age of the Shansonggang flora is considered the Early Jurassic.This study would be beneficial for better understanding the paleoecological and paleoclimatic characteristics of the Shansonggang Basin. Based mainly on the characters of the flora, the authors suggest that the Lower Jurassic coal-bearing strata, the Shansongang Formation, should namely be renewed.     

Early Jurassic Flora and Stratigraphy from Shansonggang of Southern Jilin,China

1IntroductionThe Shansonggang Basin, one of the Mesozoic coal-bearing basins in northeastern China, is located in southern Jilin Province, China and covering about 30 km2(Fig.1). The basin is lying in the northwest-ern margin of the Longgang anticline, just opposite to the Yihe Basin which lies in the southeastern margin of the anticline. During 1940s~1970 s, a lot of work on the survey of coal geology was made in the basin, but there has been a little knowledge about the plant fossils…     

Changes of taxonomical composition of Late Jurassic-Early Cretaceous palynofloras of Bureya Basin,Russia

The changes of taxonomical composition of the Late Jurassic-Early Cretaceous palynofloras are revealed,in the upper stream of Bureya River in Bureya Basin.The palynofloras are dominated as follows:the Berriasian one by ferns(Cyatheaceae,Dicksoniaceae,Osmundaceae),Classopollis and bisaccate pollen;the Valanginian-Hauterivian one by ferns(Cyatheaceae,Dicksoniaceae),Ginkgocycadophytus and bisaccate pollen;the Barremian one by ferns(Cyatheaceae,Dicksoniaceae);the Aptian one by ferns(Cyatheaceae,Dicksoniaceae,Gleicheniaceae) and Ginkgocycadophytus;and the Albian one by ferns(Schizaeaceae) and bisaccate pollen.In the Albian the floral diversity raises with the angiosperms appearing.     

Changes of taxonomical composition of Late Jurassic- Early Cretaceous palynofioras of Bureya Basin, Russia

The changes of taxonomical composition of the Late Jurassic- Early Cretaceous palynofloras are revealed, in the upper stream of Bureya River in Bureya Basin. The palynofloras are dominated as follows： the Berriasian one by ferns （Cyatheaceae, Dicksoniaceae, Osmundaceae）, Classopollis and bisaccate pollen; the Valanginiar-Hauterivian one by ferns （Cyatheaceae, Dicksoniaceae）, Ginkgocycadophytus and bisaccate pollen; the Barremian one by ferns （Cyatheaceae, Dicksoniaceae）; the Aptian one by ferns （Cyatheaceae, Dicksoniaceae, Gleicheniaceae） and Ginkgocycadophytus; and the Albian one by ferns （Schizaeaceae） and bisaccate pollen. In the Albian the floral diversity raises with the angiosperms appearing.     

A new high-resolution Late Glacial-Holocene climatic record from eastern Nanling Mountains in South China

A 350-cm-long sediment core sequence from Dahu Swamp situated in the eastern Nanling Mountains was selected for high-resolution paleoclimatic reconstruction since the Late Glacial period. The multi-proxy records of this paper reveal several evidently dry and cold events that may coincide with the Oldest Dryas, the Older Dryas, the Younger Dryas in the late deglacial period. Two relatively wetter and warmer phases occurred in ca. 15,000–14,400 cal yr B.P. and 13,500–12,800 cal yr B.P. respectively may correspond to the Bølling and Allerød warming events. The Younger Dryas event (ca. 12,800–11,500 cal yr B.P.) revealed by multi-proxies was characterized by relatively colder and drier climate. A warmer and wetter climate, occurred in ca. 10,000–6000 cal yr B.P., was consistent with the Holocene Optimum, which coincided with the maximum Northern Hemisphere insolation. The “8.2kyr cool event” and even the “8.8kyr cool event” were indicated as well from our sediment core. A dry mid-Holocene period (ca. 6000–3000 cal yr B.P.) indicated by multi-proxies does not follow the traditional concept of the wet mid-Holocene conditions observed in other regions in China.     

Division and correlation of Yixian Formation in western Liaoning,China

The Yixian Formation is a series of volcanic-sedimentary rocks in Biepiao area of Liaoning Province.It is mainly composed of basic and intermediate-basic volcanic lava,pyroclasts and terrestrial sedimentary rocks.Based on the regularity of volcanic activity,the Yixian Formation was divided by the present authors into four members in ascending order:the first member is of basal conglomerate,basic and intermediate-basic volcanic rocks;the second member is of lake phrase sedimentary rocks,or in another word,precious fossil-rich sedimentary beds;the third is of basic volcanic rocks;and the fourth is of upper conglomerate.Field mapping and comprehensive study also indicate that there are abundant vertebrate fossils (mainly of Psittacosaurus) in the first member of the Yixian Formation,and the Jehol Biota (including Sinosauropterxy,Confuciusorns sanctus,Archaefructus,etc.) is yielded in the second member of Yixian Formation.From west to east,the volcanic activity of Yixian Formation changed regularly from early to late,and from basic and intermediate-basic to acid (alkali).     

Early Cretaceous precious fossil-bearing beds in Weijialing—Yaolugou of Jianchang Basin,western Liaoning

The Jianchang Basin is one of the main localities of the precious fossils of Jehol Biota in western Liaoning. The fossil-bearing horizons are mainly in the Yixian- and Jiufotang formations. In the Weijialing- Yaolugou of southwest Jianchang Basin, many precious fossils have been found at Luojiagou Bed of the 2nd Member of the Yixian Formation and at Xidian Bed of the 1 st member of the Jiufotang Formation. The geologic setting, sedimentary environment and paleogeography of the precious fossil-bearing beds were also studied.     

Early Cretaceous precious fossil-bearing beds in Weijialing－Yaolugou of Jianchang Basin , western Liaoning

The Jianchang Basin is one of the main localities of the precious fossils of Jehol Biota in western Liaoning. The fossil-bearing horizons are mainly in the Yixian- and J iufotang formations. In the Weijialing－Yaolugou of southwest Jianchang Basin, many precious fossils have been found at Luojiagou Bed of the 2nd Member of the Yixian Formation and at Xidian Bed of the 1st member of the Jiufotang Formation. The geologic setting, sedimentary environment and paleogeography of the precious fossil-bearing beds were also studied.     

西沙群岛海域鸢乌贼摄食与繁殖生物学初步研究

鸢乌贼是南海重要的渔业资源之一,是大型光诱罩网渔船的主要捕捞对象。以2011年4个季度西沙海域光诱罩网船作业随机采集的542尾鸢乌贼(Sthenoteuthis oualaniensis)为样本,研究其摄食与繁殖生物学特性。结果表明:鸢乌贼雌雄比为1∶1,雌性成熟高峰期为冬季,平均性成熟指数(gonad somatic index,GSI)为2.97,雄性成熟高峰期为夏季,平均GSI为1.89;胴长171 mm以上雌性个体出现一次性腺发育高峰期,GSI达到8.59,111～140 mm胴长组雄性个体出现一次性腺发育高峰期,GSI为1.92,雌、雄GSI随胴长变化均较显著(p值<0.05);雌、雄初次性成熟胴长分别为159 mm和83 mm;同一胴长组中雌、雄个体的平均饵料质量差异性不显著(p值>0.05),但雌性个体最大饵料质量大于雄性个体;雌雄鸢乌贼摄食强度随胴长增加呈现总体上升的趋势,摄食等级除夏季以2级和3级为主外,其余各季度均以3级和4级为主,其中,3、4级在春季和冬季分别占71.02%和79.02%;空胃率(摄食等级为0)在秋季所占比例较高,为16.22%,其余3个季度空胃率均不超过5%,摄食对象以鱼类、头足类和甲壳类为主,且有同类相残现象。     

A new pterosaur (Pterosauria) from Middle Jurassic Tiaojishan Formation of western Liaoning,China

A new pterosaur Archaeoistiodactylus linglongtaensis gen. et sp. nov. is erected based on an incomplete skeleton with a partial skull and lower jaw. The new taxon is characterized by circular tooth sockets of anterior mandibular teeth,the anterior teeth of the upper jaw bearing posteriorly directed crowns,a relatively short metacarpus,and wing phalanges 2 and 3 and the tibia subequal in length. It possesses some plesiomorphic characters such as short metacarpals and circular tooth sockets. The pointed jaw tip present in the new taxon indicates that the expanded jaw tips of later istiodactylids are a derived character state,and the new taxon represents the first istiodactylus-like pterosaur found from the pre-Late Jurassic deposits,which provides a key role in our understanding the origin and evolution of the known istiodactylid pterosaurs. Archaeoistiodactylus is regarded as the ancestor form of the known istiodactylid pterosaur.     

The first dinosaur tracksite from Xinjiang, NW China (Middle Jurassic Sanjianfang Formation, Turpan Basin)——a preliminary report

A new dinosaur tracksite was discovered in a steeply inclined sandstone layer of the Middle Jurassic Sanjianfang Formation in the Shanshan area of the Turpan Basin. The site is the first record of dinosaur footprints from Xinjiang Province in northwestern China. More than 150 tridactyl theropod dinosaur footprints are preserved as positive hyporeliefs on the lower bedding plane of a fine-grained sandstone body. Most of the footprints are isolated and appear to be randomly distributed. Some show well defined phalangeal pads, heels and rarely indistinct impressions of the distal part of the metatarsus. Two distinct morphotypes are present: a larger type with relatively broad pads shows similarities to Changpeipus and Megalosauripus, and a slightly smaller, slender and gracile type which is similar to Grallator, Eubrontes and Anchisauripus. In both morphotypes, digit III is the longest with a length between 11.4 and 33.6 cm. A single imprint shows prominent scratches, probably formed during slipping of the track maker.     

Preliminary study on PAH degradation by bacteria from contaminated sediments in Xiamen Western Sea,Fujian, China

In order to estimate the biodegradation of three polycyclic aromatic hydrocarbons (PAHs) compounds, bacterial strains were isolated from marine sediments in three heavily contaminated sites (Yuandang Lake, Dongdu Port and Aquacultural zones in Maluan Bay) in Xiamen Western Sea. The results show three bacterial strains, which used pyrene as the sole carbon source, were identified as strains of Aureobacterium sp.,Arthrobacter sp., Rhodococcus sp. The PAH-degrading bacteria isolated had a strong ability to degrade phenanhrene, fluoranthene and pyrene at different degradation rates. The highest degradation rate was observed when three PAH compounds were mixed with an individual strain in the medium. The three PAHs were degraded after one week with a degradation rate of 89.94 % for phenanthrene and 93.4 % for both of fluoranthene and pyrene.In addition, after 25 days of incubation, the degradation rate was 99.98 % for phenanthrene and 99.97 % for both of fluoranthene and pyrene. Optical density was measured to estimate bacterial growth during the degradation of PAHs. Highest levels of bacterial growth were observed with a three PAH mixture in the culture, suggesting that the concentration of PAHs influenced bacterial growth and the highest levels of degradation for most series were detected after one week of incubation.     

Preliminary study on Late Triassic to Early Jurassic strata and floral variation in Hechuan region of Chongqing,southern Sichuan Basin

The end-Triassic mass extinction event is extensively known, however, the terrestrial response of this event is still poorly understood. Here we briefly report our preliminary results on the variation of floral diversity through the Triassic/Jurassic boundary deposits in the Tanba section of Hechuan region, Chongqing, southern China. It is recognized that the floral biodiversity of the Hechuan region shows a distinct change through the Triassic and Jurassic transition; and the floral diversity loss reaches up to 92 5% at species level. Meanwhile, in northeastern region of the Sichuan Basin, the floral diversity declines by about 50% across the T/J boundary at species level with a remarkable turnover of genera and species. The potential reasons and mechanisms that cause the floral diversity differentiation of the T/J boundary in the Sichuan Basin are briefly discussed in this note.