A new chasmosaurine from northern Laramidia expands frill disparity in ceratopsid dinosaurs

A new taxon of chasmosaurine ceratopsid demonstrates unexpected disparity in parietosquamosal frill shape among ceratopsid dinosaurs early in their evolutionary radiation. The new taxon is described based on two apomorphic squamosals collected from approximately time equivalent (approximately 77 million years old) sections of the upper Judith River Formation, Montana, and the lower Dinosaur Park Formation of Dinosaur Provincial Park, Alberta. It is referred to Chasmosaurinae based on the inferred elongate morphology. The typical chasmosaurine squamosal forms an obtuse triangle in dorsal view that tapers towards the posterolateral corner of the frill. In the dorsal view of the new taxon, the lateral margin of the squamosal is hatchet-shaped with the posterior portion modified into a constricted narrow bar that would have supported the lateral margin of a robust parietal. The new taxon represents the oldest chasmosaurine from Canada, and the first pre-Maastrichtian ceratopsid to have been collected on both sides of the Canada–US border, with a minimum north–south range of 380 km. This squamosal morphology would have given the frill of the new taxon a unique dorsal profile that represents evolutionary experimentation in frill signalling near the origin of chasmosaurine ceratopsids and reinforces biogeographic differences between northern and southern faunal provinces in the Campanian of North America.     

Chimären in der entwicklungsbiologischen Forschung

Chimeras produced from amphibian, mammalian, and especially avian embryos have provided important insights into vertebrate development. Important contributions have led to new concepts in understanding the development of, for example, the nervous system, the vascular system, and the skeletal muscles. The migration of cells is particularly accessible in chimeras. More important results are to be expected from chimeras in the future, especially by combining this approach with other state-of-the-art techniques.     

A new neosuchian with Asian affinities from the Jurassic of northeastern Brazil

Phylogenetic relationships near the origin of extant crocodylians are weakly supported, and this lack of resolution makes for poor estimates of taxonomic and morphological diversity. Previously known taxa are found throughout the Cretaceous in Laurasia and at a few sites from Brazil, Australia, and northern Africa. Here, we report Batrachomimus pastosbonensis gen. et sp. nov. from the Late Jurassic of northeastern Brazil, which is deeply nested within Neosuchia and associated to the Cretaceous Asian paralligatorids. The new taxon predates all other members of Paralligatoridae and its immediate sister group (including Eusuchia) by 30 million years. A nearly complete skull, osteoderms, and limb bones were recovered, and autapomorphies of B. pastosbonensis include a scalloped lateral margin of the rostrum in dorsal view, unsculpted alveolar margin at the caudalmost portion of the maxilla, blunt lateral prongs on the jugal at the base of the postorbital bar, hourglass shaped choanae, and pterygoid choanal septum extended between the palatal shelves of the palatines. The crocodyloid-like skull proportions and the slender, conical teeth suggest an amphibious and piscivorous life history to this 1 m long animal.

     

A new fossil mustelid from the Miocene of South Dakota,USA

A skull from the Barstovian of South Dakota has typical leptarctine characteristics, including robust zygomatic arches, double sagittal crests, grooves on the lingual side of the lower canines, and bony projections from the tympanic bullae. The robust mandibles and expanded masseteric fossa of this specimen indicate that it had large jaw muscles. Dental morphology and other characters lead us to agree with earlier suggestions that Hypsoparia is a valid genus. The morphology of Hypsoparia suggests that leptarctines were more herbivorous than most other Carnivora.     

Cranial pneumatization and auditory perceptions of the oviraptorid dinosaur <Emphasis Type="Italic">Conchoraptor gracilis</Emphasis> (Theropoda,Maniraptora) from the Late Cretaceous of Mongolia

The distribution of air-filled structures in the craniofacial and neurocranial bones of the oviraptorid ZPAL MgD-I/95, discovered at the Hermiin Tsav locality, Mongolia, is restored. Based on the complete obliteration of most of the cranial sutures, the specimen is identified as an adult individual of Conchoraptor gracilis Barsbold 1986. Except for the orbitosphenoids and epipterygoids, the preserved bones of the neurocranium are hollow. Three types of tympanic recess are present in Conchoraptor, a characteristic shared with troodontids, dromaeosaurids, and avian theropods. The contralateral middle ear cavities are interconnected by the supraencephalic pathway that passes through the dorsal tympanic recesses, the posterodorsal prootic sinuses and the parietal sinus. The spatial arrangements of the middle ear cavity and a derived neurocranial pneumatic system in Conchoraptor indicate enhancements of acoustic perception in the lower-frequency registers and of auditory directionality. We further speculate that this improvement of binaural hearing could be explained as an adaptation required for accurate detection of prey and/or predators under conditions of low illumination. The other potentially pneumatic structures of the Conchoraptor cranium include (1) recessus-like irregularities on the dorsal surface of the nasal and frontal bones (a putative oviraptorid synapomorphy; pos); (2) a subotic recess; (3) a sub-condylar recess; and (4) a posterior condylar recess (pos). Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

A new basal galeomorph shark (Synechodontiformes, Neoselachii) from the Early Jurassic of Europe

Palaeospinacids are a group of basal galeomorph sharks and are placed in the order Synechodontiformes (Chondrichthyes, Neoselachii) ranging from the Permian to the Eocene. Currently, there is a controversy concerning the identity of diagnostic characters for distinguishing palaeospinacid genera because of very similar dental morphologies and the scarcity of articulated skeletal material. The most notable character for distinguishing species within the Palaeospinacidae is, however, the dental morphology. The main dental character uniting all palaeospinacids is the very specialised pseudopolyaulacorhize root vascularisation. A re-examination of articulated neoselachian skeletons from the Lower Jurassic of Lyme Regis (England) and Holzmaden (S Germany), and recently discovered specimens from the Upper Jurassic of the Solnhofen area and Nusplingen (S Germany) has yielded several hitherto unrecognised complete skeletons of the palaeospinacids Synechodus and Paraorthacodus enabling a re-evaluation of characters. These specimens indicate that the number of dorsal fins and the presence or absence of dorsal fin spines represent important features for identifying palaeospinacids. Synechodus bears two dorsal fins without fin spines, whereas Paraorthacodus only has a single dorsal fin lacking a fin spine directly in front of the caudal fin. All palaeospinacids from the Early Jurassic have two spines supporting the dorsal fins and are consequently assigned to a new genus, Palidiplospinax nov. gen. Three species are placed into the new taxon: Synechodus enniskilleni, S. occultidens and S. smithwoodwardi.     

An unusual archosaurian from the marine Triassic of China

A new Triassic archosaurian from China shows a number of aquatic specializations, of which the most striking is the extreme lateral compression of the long tail. Others that may also reflect aquatic adaptations include platelike scapula and coracoid, elongate neck with extremely long and slender ribs, and reduction of osteoderms. In contrast, its pelvic girdle and hind limb have no aquatic modifications. Anatomic features, taphonomy, and local geological data suggest that it may have lived in a coastal–island environment. This lifestyle, convergent with some Jurassic marine crocodyliforms that lived at least 40 million years later and the saltwater species of extant Crocodylus, contradicts with the prevailing view that Triassic archosaurians were restricted to nonmarine ecosystems. Its mosaic anatomy represents a previously unknown ecomorph within primitive archosaurians.Electronic Supplementary Material  Supplementary material is available for this article at     

土壤的苏打盐渍化与地方性氟病

从野外样品的分析和理论分析两方面证明,在苏打盐渍化过程中,土壤溶液的pH值增高,K~ 、Na~ 、HCO_3~-、CO_3~(2-)含量增加,这将导致水溶性氟在土壤中的集聚并形成高氟地下水.阐明了在我国北方苏打盐渍化区与潜水高氟型地方性氟病区一致的原因.潜水高氟型地方性氟病区往往发生过古代苏打盐渍化过程,在此过程中积聚的水溶性氟是现代高氟地下水中氟的重要来源.中更新世是我国北方风化壳和土壤中水溶性氟积聚的重要时期.     

Development of the lateral line mechanoreceptors in the catfish Silurus glanis

In fish the neuromasts of the lateral line develop as follows: a “migrating primordium” (MP) migrates from the postotic placode along the future posterior lateral line canal to the tail fin. Its placodal cells are assumed to be the basis for the development of the neuromasts. However, an MP was not found in all fish, e.g., in catfish. In the present study, a search was made for the MP in the larvae of the catfish Silurus glanis. Using light and electron microscopy, an MP was found to migrate along the ventral rim of the tail. It precedes the formation of a ventral row of free neuromasts. An MP preceding the main lateral row of the future canal neuromasts was not found. The necessity of the MP for the ventral-free neuromast development is shown by making incisions which block its migration. The result: caudal to the incision site neuromasts do not develop. On the other hand, the same incision procedure applied to the assumed migration route of a—hypothetical—lateral MP does not block the development of the lateral neuromasts. It is concluded that in this case an MP is not necessary for the development of the canal neuromasts.     

Complex rostral neurovascular system in a giant pliosaur

Pliosaurs were a long-lived, ubiquitous group of Mesozoic marine predators attaining large body sizes (up to 12 m). Despite much being known about their ecology and behaviour, the mechanisms they adopted for prey detection have been poorly investigated and represent a mystery to date. Complex neurovascular systems in many vertebrate rostra have evolved for prey detection. However, information on the occurrence of such systems in fossil taxa is extremely limited because of poor preservation potential. The neurovascular complex from the snout of an exceptionally well-preserved pliosaur from the Kimmeridgian (Late Jurassic, c. 170 Myr ago) of Weymouth Bay (Dorset, UK) is described here for the first time. Using computed tomography (CT) scans, the extensive bifurcating neurovascular channels could be traced through the rostrum to both the teeth and the foramina on the dorsal and lateral surface of the snout. The structures on the surface of the skull and the high concentrations of peripheral rami suggest that this could be a sensory system, perhaps similar to crocodile pressure receptors or shark electroreceptors.     

长江中游岸线资源与开发利用适宜性评价分析

长江中游岸线资源丰富,开发利用价值较大。通过充分分析长江中游岸线资源特征与地质环境条件,从地质学角度构建港口码头、过江隧道与过江大桥等重大工程建设适宜性评价模型,运用层次分析法（AHP）划定出三种工程类型一级岸线（适宜）、二级岸线（较适宜）、三级岸线（一般适宜）与四级岸线（非优先开发）区域范围。由结果可知：长江中游岸线港口码头以非优先开发区域为主,长度合计931.47 km,占岸线总长的46.71%;过江隧道与过江大桥以较适宜开发、一般适宜开发区域为主,较适宜开发、一般适宜开发区长度合计分别为1550.75 km、1224.18 km,占岸线总长的77.77%、61.39%。最后,针对三种工程类型适宜性等级特征提出相应地学对策建议,为重大工程部署规划提供地学理论依据,促进长江中游岸线资源科学合理开发利用与有效保护,以期推动长江经济带发展与国土空间规划,保护大长江持续健康发展。     

南黄海浒苔绿潮暴发区氨基酸时空分布特征

根据南黄海绿潮发展过程将浒苔绿潮区分为35°N以南和35°N以北2个区域,并利用2018年南黄海海域春、夏季2个航次的调查数据研究分析了浒苔绿潮发生前后2个区域总溶解氨基酸（TDAA）、溶解游离氨基酸（DFAA）的分布特征及变化规律.结果表明,TDAA和DFAA的浓度均基本呈现近岸高远岸底的水平分布特点,35°N以南海域夏季相对于春季水体TDAA、DFAA的浓度整体呈现上升趋势,其中TDAA浓度升高程度明显,表、中层TDAA浓度分别升高了24.8%、60.6%,而35°N以北海域水体中TDAA的浓度却降低了8.7%,其中表层水体TDAA含量下降了30.1%.在DIN浓度较低的35°N以北海域,浒苔的吸收利用可能是造成该区域表层水体TDAA含量降低的重要原因.由此可见,35°N以北海域水体氨基酸等小分子有机氮对浒苔绿潮后期的维持发展起着重要的支持作用.     

蚌埠城市水生态安全动态变化的定量评价与分析

以淮河中游蚌埠城市水环境系统为主要研究对象,采用因子分析法对淮河蚌埠段水生态安全的年际变化进行综合评价,结果表明:1985-2003年间蚌埠城市水生态安全总体呈好转趋势,城市社会经济发展、工农业污染源状况及水污染治理与控制能力等是影响水生态安全变化的主要因素,并提出建立生态安全预警体系、开展水生态环境规划及推进产业生态化等保障城市水生态安全的主要对策措施.     

近50年来河西走廊地下水资源变化及对生态环境的影响

利用不同时期出山地表水资源和相应的地下水均衡计算结果,分析对比了近50年来河西走廊地下水资源变化特征。结果表明,自20世纪50年代以来,出山地表水资源年际变化相对比较稳定。与此同时,随着中游地区工农业生产的持续发展和水利化程度的日臻完善,地下水补给量逐步减少,由1955年的62.413×108m3减少到1999年的55.514×108m3,减少了6.899×108m3。由此引起了区域性地下水位持续下降、泉水资源大幅度削减、地下水开采规模和开采量逐年扩大、进入下游的地表水不断减少、水质恶化等水文地质问题。伴随着水资源利用分布格局的改变,河西走廊生态环境体系不断演变并趋于恶化。     

论我国西部大开发战略中的旅游开发与贫困消除

大量调查研究表明,许多地区旅游资源的分布与贫困人口的分布是高度重叠的,尤其是那些区位偏远以及交通不便的地区,自然景观受人类活动干扰较小,自然生态系统保存较为完整,适合开发、发展生态旅游产业。因此,将旅游开发与扶贫有机结合应是消除贫困的最有效途径。论文针对这一问题论述了如下若干问题:其一,我国贫困县的分布与高品位生态旅游资源的分布高度重叠;其二,我国贫困县的分布与这些生态旅游资源的分布均在中西部地区,消除贫困与发展中西部旅游应是西部大开发战略的重要组成部分;其三,旅游在扶贫方面的优势是其他任何产业所无可比拟的;其四,应着手构建中国PPT旅游(ProPoorTourism,即有利于贫困人口发展的旅游)战略以及发展PPT旅游的战略措施,以期尽快消除我国的贫困问题。     

长江口污染物运动轨迹模拟

长江口流域污染物排放较多,受地形和水环境过程影响其运动规律极为复杂。为保护近岸海域水质环境,须在洞悉该区域环境水动力基础上开展污染物运动规律的研究。基于ECOMSED三维数值模型和拉格朗日粒子追踪技术,采用单个粒子以及粒子群模拟追踪了长江口的石洞口、竹园、白龙港三大污水排污口区域污染物质的运动轨迹,重点分析了水体表层、中层、底层污染物的运动特性及其影响范围,在此基础上,对该区域水体的排污设置方式提出了参考建议。     

Male wing color properties predict the size of nuptial gifts given during mating in the Pipevine Swallowtail butterfly (Battus philenor)

In many animals, males bear bright ornamental color patches that may signal both the direct and indirect benefits that a female might accrue from mating with him. Here we test whether male coloration in the Pipevine Swallowtail butterfly, Battus philenor, predicts two potential direct benefits for females: brief copulation duration and the quantity of materials the male passes to the female during mating. In this species, males have a bright iridescent blue field on the dorsal hindwing surface, while females have little or no dorsal iridescence. Females preferentially mate with males who display a bright and highly chromatic blue field on their dorsal hindwing. In this study, we show that the chroma of the blue field on the male dorsal hindwing and male body size (forewing length) significantly predict the mass of material or spermatophore that a male forms within the female’s copulatory sac during mating. We also found that spermatophore mass correlated negatively with copulation duration, but that color variables did not significantly predict this potential direct benefit. These results suggest that females may enhance the material benefits they receive during mating by mating with males based on the coloration of their dorsal hindwing.     

洱海表层沉积物中磷形态分布及pH、DO影响的分析

研究了洱海代表性区域表层沉积物中总磷分布及不同形态磷赋存特征,探讨了pH值及溶解氧对沉积物中总磷和各形态磷赋存状态的影响。结果表明洱海表层沉积物中总磷和不同形态磷分布不均,总磷含量湖心高于湖口,湖心区域闭蓄态磷(BD-P和Al-P)和生物有效态磷占总磷的比例较高,更容易受pH和DO的影响,碱性和厌氧条件会增加洱海湖心底泥中磷的潜在释放能力。     

太行山区水循环及其对华北平原地下水补给的研究

山区水循环研究不仅对山区本身, 对与其相连的山前平原地下水的补给也具有重要意义。太 行山区作为华北平原的重要水源补给区, 其水循环现状以及对华北平原地下水的补给研究尚少, 许 多机理还不明确。研究通过阐述山区水循环过程与机理, 结合地处太行山中段的牛家庄实验流域的 实例研究, 对太行山区对华北平原地下水的补给过程进行了分析。2004 年4-11 月的研究结果表 明, 牛家庄流域对山前的侧向补给量为1.53×106m3, 补给系数(补给总量/降水总量)为0.242。流域的 下游补给系数最大, 中游次之, 上游最小。最后, 用概念模型对太行山区流域水循环机制和山前侧向 补给的机理进行了阐述。     

利用电子探针对水泥净浆中Cr、As、Pb分布特征的研究

通过在模拟水泥窑中高温煅烧含Cr、As、Pb的水泥生料,制取水泥熟料,进而制备水泥净浆片.然后利用电子探针的点、线、面分析,研究了水泥净浆中Cr、As、Pb的整体分布特征及在不同矿物相中的具体分布特征,以揭示Cr、As、Pb在其中的微观物理化学形态,为建立Cr、As、Pb的释放机制提供理论基础.结果表明,Cr在水化硅酸...