Triassic-jurassic tetrapod extinctions: are they real?

Terrestrial vertebrate fossils show that part of the Newark supergroup of the eastern United States, all of the Glen Canyon group of the southwestern United States, and the Upper Stormberg group of southern Africa are Early Jurassic. This new correlation demonstrates that the supposed widespread tetrapod extinction at the Triassic-Jurassic boundary is an artifact of spurious correlation.     

A primitive enantiornithine bird and the origin of feathers

A fossil enantiornithine bird, Protopteryx fengningensis gen. et sp. nov., was collected from the Early Cretaceous Yixian Formation of Northern China. It provides fossil evidence of a triosseal canal in early birds. The manus and the alular digit are long, as in Archaeopteryx and Confuciusornis, but are relatively short in other enantiornithines. The alula or bastard wing is attached to an unreduced alular digit. The two central tail feathers are scalelike without branching. This type of feather may suggest that modern feathers evolved through the following stages: (i) elongated scale, (ii) central shaft, (iii) barbs, and finally (iv) barbules and barbicel.     

Fossil spores, pollen, and fishes from connecticut indicate early jurassic age for part of the newark group

Palynologically productive localities have been found in the United States throughout the Newark Group basins, most of which had previously been assumed to be barren. Rich palynoflorules dominated by coniferous pollen of Circulina-Classopollis type, and well-preserved fossil fishes, including possible new semionotids, have been found in the Hartford basin. Palynological data indicate that the Newark Group has considerable time-stratigraphic range: Upper Triassic for the Cumnock Formation (North Carolina), the Vinita Beds (Virginia), and the upper New Oxford Formation (Pennsylvania), Rhaeto-Liassic for the Brunswick Formation (New Jersey), Portland Formation (Connecticut and Massachusetts), and the Shuttle Meadow Formation (Connecticut).     

A Cretaceous scleractinian coral with a calcitic skeleton

It has been generally thought that scleractinian corals form purely aragonitic skeletons. We show that a well-preserved fossil coral, Coelosmilia sp. from the Upper Cretaceous (about 70 million years ago), has preserved skeletal structural features identical to those observed in present-day scleractinians. However, the skeleton of Coelosmilia sp. is entirely calcitic. Its fine-scale structure and chemistry indicate that the calcite is primary and did not form from the diagenetic alteration of aragonite. This result implies that corals, like other groups of marine, calcium carbonate-producing organisms, can form skeletons of different carbonate polymorphs.     

柴达木盆地柴西南地区上干柴沟组沉积相研究

在分析大量钻井、测井剖面以及相标志的基础上,对柴西南地区上干柴沟组沉积相进行了研究。研究表明,该研究区发育湖泊相、辫状河三角洲相、湖底扇相3种沉积相类型,其中浅湖亚相是湖泊相中的主要亚相类型,由浅湖砂坝、浅湖泥、浅湖灰泥、藻灰岩、浅湖鲕粒(生物碎屑)滩和风暴沉积组成。辫状河三角洲相以发育辫状河三角洲前缘亚相为主,该亚相可进一步划分为水下分流河道、水下天然堤、支流间湾和河口砂坝微相;湖底扇相主要发育于七个泉地区,其中发育典型浊积岩层序序列。     

A nearly modern amphibious bird from the Early Cretaceous of northwestern China

Three-dimensional specimens of the volant fossil bird Gansus yumenensis from the Early Cretaceous Xiagou Formation of northwestern China demonstrate that this taxon possesses advanced anatomical features previously known only in Late Cretaceous and Cenozoic ornithuran birds. Phylogenetic analysis recovers Gansus within the Ornithurae, making it the oldest known member of the clade. The Xiagou Formation preserves the oldest known ornithuromorph-dominated avian assemblage. The anatomy of Gansus, like that of other non-neornithean (nonmodern) ornithuran birds, indicates specialization for an amphibious life-style, supporting the hypothesis that modern birds originated in aquatic or littoral niches.     

Attempt to date early South african hominids by using fission tracks in calcite

Calcite crystals extracted from marrow cavities of bones found in hominid-bearing breccias from Makapansgat and Swartkrans were studied for fossil tracks. The absence of the expected numbers of tracks in these and in calcites from Beds I and II, Olduvai Gorge, combined with the results of laboratory heating experiments, indicates that track annealing has occurred at ambient temperatures and precludes the widespread use of calcite for fission track dating.     

Early evolution of avian flight and perching: new evidence from the lower cretaceous of china

Fossil bird skeletons discovered in Lower Cretaceous lake deposits in China shed new light on the early evolution of avian flight and perching. The 135 million-year-old sparrow-sized skeletons represent a new avian, Sinornis santensis, n. gen. n. sp., that preserves striking primitive features such as a flexible manus with unguals, a footed pubis, and stomach ribs (gastralia). In contrast to Archaeoperyx, however, Sinornis exhibits advanced features such as a broad sternum, wing-folding mechanism, pygostyle, and large fully reversed hallux. Modern avian flight function and perching capability, therefore, must have evolved in small-bodied birds in inland habitats not long after Archaeopteryx.     

松材线虫及携带细菌对黑松复合的侵染

从不同松树上分离松材线虫、拟松材线虫、滑刃线虫和小杆线虫,并从松材线虫和小杆线虫体上分离细菌,将线虫无菌化处理后与从线虫体上分离到的荧光假单胞杆菌、产气肠杆菌混合接种无菌黑松苗和愈伤组织。结果表明,单独接种无菌线虫或细菌不能使黑松致病,无菌松材线虫、无菌拟松材线虫只有与有毒性的荧光假单胞杆菌混合接种时才能使黑松无菌苗和愈伤组织发病,细菌通过线虫携带在树体内传播扩散,使松树致病。研究进一步证明了线虫和细菌在松材线虫病致病过程中起协同作用。     

Pollen and spores date origin of rift basins from Texas to nova scotia as early late triassic

Palynological studies of the nonmarine Newark Supergroup of eastern North America and of rift basins in the northern Gulf of Mexico facilitate correlation with well-dated marine sections of Europe. New information emphasizes the chronological link between the Newark basins and a Gulf of Mexico basin and their common history in the rifting of North America from Pangea. Shales from the subsurface South Georgia Basin are shown to be of late Karnian age (early Late Triassic). The known time of earliest sedimentation in the Culpeper Basin is extended from Norian (late Late Triassic) to mid-Karnian, and the date of earliest sedimentation in the Richmond and Deep River basins is moved to at least earliest Karnian, perhaps Ladinian. The subsurface Eagle Mills Formation in Texas and Arkansas has been dated palynologically as mid- to late Karnian. The oldest parts of the Newark Supergroup, and the Eagle Mills Formation, mostly began deposition in precursor rift basins that formed in Ladinian to early Karnian time. In the southern Newark basins, sedimentation apparently ceased in late Karnian but continued in the northern basins well into the Jurassic, until genesis of the Atlantic ended basin sedimentation.     

3种划蝽食性的初步研究

以水绵、丝藻、死鱼、活鱼、活水草、死水草和底泥为供试食物,以存活时间、消化道残留物的颜色和食物的变化为依据,推断3种划蝽在实验室内的取食食物.研究表明,3种划蝽均能利用水藻和腐烂有机物,但它们的营养生态位发生了分化,显斑原划蝽(Cymatia apparens (Distant))嗜好取食丝藻,并能取食水绵、腐烂水草和死鱼,但不能利用底泥;钟丽烁划蝽(Sigara bellula (Horvath))嗜好水绵,能利用腐烂水草、底泥、丝藻和死鱼;沙棘小划蝽(Micronecta sahibergi (Jakovlev))嗜好丝藻和底泥,能取食死鱼、腐烂水草和水绵.     

Early cretaceous angiosperm leaves from southern South america

Early angiosperm leaves from the Aptian (113 to 119 million years ago) Baqueró Formation of Patagonia have been found in a fossil flora dominated by more than 100 species of gymnosperms and pteridophytes. They may be the first early Cretaceous angiosperm leaves to be reported from southern South America and one of the few reported in the Southern Hemisphere. The leaves are large, lobate, craspedodromous, and dentate (A-1 teeth) and have ramified tertiary veins and random fourth-order venation. Several of these features have been found in coeval and younger strata elsewhere, but not in the same combination. They were probably a marginal component of the flora.     

Baja california: late cretaceous dinosaurs

Late Cretaceous dinosaurs have been discovered along the Pacific margin of Baja California. The presence of Hypacrosaurus sp. is suggestive of correlation with the Upper Edmonton Formation, Alberta. Dissimilarities between the Baja California fauna and those from contemporary units along the eastern trend of the Rocky Mountains suggest that Baja California was ecologically separated from mainland Mexico during late Campanian and early Maastrictian time.     

An Early Cretaceous tribosphenic mammal and metatherian evolution

Derived features of a new boreosphenidan mammal from the Lower Cretaceous Yixian Formation of China suggest that it has a closer relationship to metatherians (including extant marsupials) than to eutherians (including extant placentals). This fossil dates to 125 million years ago and extends the record of marsupial relatives with skeletal remains by 50 million years. It also has many foot structures known only from climbing and tree-living extant mammals, suggesting that early crown therians exploited diverse niches. New data from this fossil support the view that Asia was likely the center for the diversification of the earliest metatherians and eutherians during the Early Cretaceous.     

10色板对鲜食葡萄3种主要害虫的诱捕效果

利用10种颜色制成的粘虫板于2011年5月7日至2011年11月1日在鲜食葡萄(莫尔格瓦)上测试了葡萄主要害虫绿盲蝽、葡萄二星叶蝉以及葡萄二黄斑叶蝉3种害虫成虫对不同颜色粘虫板的诱捕效果。结果表明,10种色板诱捕到绿盲蝽数量较多,而诱捕到二星叶蝉和二黄斑叶蝉数量较少。经方差分析,米黄、黄色诱捕绿盲蝽效果最好,深绿、绿色、白色、土黄、红色居中,深蓝其次,最差的是黑色、天蓝色,且差异显著;诱捕的另外两种害虫二星叶蝉和二黄斑叶蝉,分别以土黄、黄色,土黄、黑色、米黄色效果最好。     

衡水湖中主要沉水植物对水质的影响

菹草（Potamogeton crispus）、轮叶狐尾藻（Myriophyllum verticillatum）和灯笼草（轮藻属（Chara）的一种）是衡水湖中生物量较大的3种沉水植物。经过采集培养并研究了这3种沉水植物对水中溶解氧含量、硝态氮含量及光密度和电导率的影响,结合实地调查,推测灯笼草的存在可能是造成近几年七八月衡水湖鸟区等游览区出现臭味和鱼苗死亡的原因,初步确定了灯笼草为造成湖水污染的沉水植物。     

Biological control of crystal texture: a widespread strategy for adapting crystal properties to function

Textures of calcite crystals from a variety of mineralized tissues belonging to organisms from four phyla were examined with high-resolution synchrotron x-ray radiation. Significant differences in coherence length and angular spread were observed between taxonomic groups. Crystals from polycrystalline skeletal ensembles were more perfect than those that function as single-crystal elements. Different anisotropic effects on crystal texture were observed for sea urchin and mollusk calcite crystals, whereas none was found for the foraminifer, Patellina, and the control calcite crystals. These results show that the manipulation of crystal texture in different organisms is under biological control and that crystal textures in some tissues are adapted to function. A better understanding of this apparently widespread biological phenomenon may provide new insights for improving synthetic crystal-containing materials.     

微细配合饲料代替单胞藻作为海湾扇贝亲贝及面盘幼虫食料的研究

用石莼、海带、礁膜、鼠尾藻分别配以动、植物蛋白质,脂肪,维生素,矿物质等研制了５种微细配合饲料,以完全代替单胞藻饲育海湾扇贝的亲贝和面盘幼虫。试验结果表明,亲贝性腺能正常发育和产卵,所得的幼虫生长,变态也均正常。     

稻田固氮细菌分离物的PCR-DGGE及其序列同源性分析

采用PCR-DGGE法对从福建稻田取得的8个固氮细菌分离物进行分子鉴定,通过测序比对,发现它们与中慢生根瘤菌(Mesorhizobiumsp.)、鞘氨醇单胞菌(Sphingomonassp.)、根瘤菌(Rhizobiumsp.)、慢生根瘤菌(Bradyrhizobiumsp.)、克雷伯氏杆菌(Klebsiellasp.)、伯克霍德尔氏菌(Burkholderia cepacia)、假单胞菌(Pseud-omonassp.)、诺卡氏菌(Nocardioides)和红球菌(Rhodococcussp.)9个属的固氮细菌具有高度同源性。     

十堰市部分地区魔芋腐烂病发病类型和重要致病菌

为了明确湖北省十堰市魔芋腐烂病的发病类型及重要致病菌,调查了十堰市不同地点魔芋腐烂病的发病类型,研究了不同地区病原菌的分离频率、优势菌种类及致病性。结果表明,魔芋发病率和发病症状因地点而异,可分为茎基环状软腐型、黄化茎基黑烂型、黄化茎黑裂型、黄化茎干软型、黄化茎基外黑内红型、茎上部或整株黒烂型六大类症状。柳陂基地魔芋发病率最高,茎基环状软腐型和黄化茎基黑烂型发病率分别为13.0%和26.9%;郧西乡魔芋发病率最低,为4.8%。从28个样品中共分离到2种真菌和11种细菌,其中真菌为齐整小核菌和镰刀菌,优势细菌为胡萝卜软腐果胶杆菌胡萝卜亚种（Pectobacterium carotovorum subsp. carotovorum）、嗜麦芽寡养单胞菌（Stenotrophomonas maltophilia）和产酸克雷伯氏菌（Klebsiella oxytoca）,分离频率分别为27.6%、17.6%和12.1%。致病性测定表明,胡萝卜软腐果胶杆菌胡萝卜亚种为魔芋软腐病的致病菌。利用胡萝卜软腐果胶杆菌特异性引物仅从被鉴定为该种的B12、B16、B17菌株中扩增出特异DNA条带。上述结果表明：魔芋腐烂病存在复合侵染,胡萝卜软腐果胶杆菌为魔芋腐烂病的重要致病菌,为魔芋腐烂病的防控提供了依据。