Echinoids as hard substrates: varied examples from the Oligocene of Antigua,Lesser Antilles

A collection of unremarkably preserved fossil irregular echinoids from the Upper Oligocene (Chattian) Antigua Formation of Antigua, Lesser Antilles, nonetheless provides evidence of a range of palaeoecological interactions. A dead test of the heart urchin Eupatagus sp. formed a hard substrate for the attachment of gregarious Thecidellina? sp., a thecidoid brachiopod. Although obligate encrusters, these brachiopods more commonly occur as disarticulated valves free of the substrate in the Antillean fossil record. Elongate pits in test fragments were formed, variously, before and after the death of the host echinoids. These depressions on the external surface were formed either by invertebrates excavating domiciles or by claws or teeth; the echinoid later reclaimed the pits and grew new tubercles in the base. Post-mortem pits lack such new tuberculation. A test of Eupatagus sp. bears the boring Oichnus isp., formed either by a predator (gastropod?) or after the death of the echinoid (domicile), and a serpulid worm tube which grew on the test subsequent to the echinoid’s death. The echinoid fauna of the Antigua Formation has been easy to collect and specimens are to be found in many museums; they now await re-examination to reveal palaeosynecological data analogous to that determined from the fragments discussed herein.     

Late Cretaceous stratigraphy,sediments and structure: Gems of the Dorset and East Devon Coast World Heritage Site (Jurassic Coast), England

Extraordinary, long-distance litho-marker beds such as the Lewes and Shoreham Tubular Flints and associated marl seams and fossils, recognised in cliff exposures and cliff-fall boulders, are keys to unlocking the stratigraphy and tectonic structures in the Late Cretaceous of the Dorset and East Devon Coast World Heritage Site (Jurassic Coast). Durdle Cove is a special gem exposing the Lewes and Seaford Chalk stratigraphy where new marker beds are identified and sediments and tectonic structures provide clues to timing of movements that produced a Late Cretaceous pericline which grew into a Miocene monocline along the line of the underlying Purbeck Reverse Fault. During ‘inversion’ along this fault some Late Cretaceous Chalk formations were in part or completely ‘lost’ (e.g. Middle Turonian New Pit Chalk Formation) and others were condensed (e.g. Late Santonian and Early Campanian Newhaven Chalk Formation). Excavation of the A354 road cutting at the Lower Bincombe Farm, has greatly added to the stratigraphical records of Late Cretaceous fossils in South Dorset, especially Coniacian and Early Campanian inoceramid bivalves and the various stratigraphically specific forms of the Late Santonian to Early Campanian echinoid fossil Echinocorys scutata spp. not recorded before in this coastline. The very large bivalve fossil Platyceramus sp. provides clues to chalk sea-floor environments.     

How bioturbation obscured the Cretaceous–Palaeogene boundary record

The Cretaceous–Palaeogene (K/Pg) boundary interval is often penetrated by burrows, which may obscure stratigraphic and micropalaeontological records, leading to misinterpretations of the sequence of events spanning the K/Pg boundary. Here, we assess the role of burrowing organisms in the redistribution of benthic foraminifera across the boundary at Bidart (France), and report a strong relationship between the behaviour represented by pre‐ and post‐K/Pg trace fossils and their benthic foraminiferal content. We further infer a brief interval of eutrophic conditions at the seafloor, as reported from other locations, which disappeared from the lowermost Danian stratigraphic record and is represented only inside post‐K/Pg trace fossils hosted in Cretaceous strata. The combined study of trace fossils and microfossils is a powerful tool in eco‐stratigraphy and event‐stratigraphy, and can yield important insights into the completeness of the K/Pg record, especially at locations such as Bidart where this interval has traditionally been assumed to be complete.     

贵州台江中寒武世凯里组中分枝状宏观藻类化石

本文描述了贵州中寒武世凯里组中的分枝状宏观藻类化石5属7种，即：Marpolia spissa Walcott,Marpolia aequalis Walcott,Guizhouella ramulosa Yang(gen.et sp.nov.),Doushantuophyton lineare Chen,Thamnophton formosus Yang(gen.et sp.nov.),Eoulothrix fibrillata Ding,Eoulothrix flabellophyton Yang(sp.mov.)。根据大量的藻类与凯里生物群共生特征，从藻类的生态及生物群分布受到沉积韵律控制等特征分析，认为凯里生物群生活环境的水深应该在30－60m，而埋藏和保存环境的水深是150m左右。另外，将凯里生物群中的宏观藻类化石与震旦纪陡山沱期的藻类化石进行了比较，两者在以分枝状藻类占主要组成上是相似的，从这一方面来说，晚震旦世宏观藻类与寒武纪宏观藻类没有大的演变，但寒武纪宏观藻类以出现钙质珊瑚藻类、分枝更加复杂的类型和具有锯齿状叶状体、生殖托构造的藻类为特征。     

扬子板块西北缘下泥盆统平驿铺组双壳类遗迹化石

四川北部广元地区下泥盆统平驿铺组产出丰富的双壳类遗迹化石,但尚未开展过系统的遗迹学工作,也未进行过行为学与古生态学分析。文中针对四川广元马家剖面平驿铺组中部地层开展沉积学和系统遗迹学研究,在陆棚至近滨带下部沉积中共识别出3个属种的双壳类遗迹化石,包括Lockeia siliquaria,Protovirgularia rugosa,Ptychoplasma vagans,以及其他无脊椎动物门类遗迹化石Cruziana problematica,Dimorphichnus isp.,Lophoctenium isp.等。对双壳类遗迹化石的出现方式、形态以及保存特征的分析表明,平驿铺组中部曾出现过2种类型的双壳类,分属具分叉足(原鳃目)和楔状足的类群。原鳃目分布于过渡带和陆棚区,营沉积物摄食生活;受高能事件或沉积物掩埋影响,它们由停息状态变为“逃逸”状态的行为产生了Pro.rugosa。具楔状足的双壳类依生态类型可分为2类：在过渡带与陆棚区,漫游的、营沉积物摄食的类型产生了Pty.vagans;而在近滨下部,滤食性双壳类居群则在不同期次高能事件的间隙对沉积物进行大规模殖居,产生了L.sil...     

康滇古陆东侧早奥陶世遗迹化且合及其指相意义

康滇古陆东侧的下奥陶统,发育有一套碎屑岩相岩石组合,遗迹化石丰富,其组合与沉积相的关系密切,起到了极好的指相佐证。遗迹化石组合有三个特点:1、Cruziana产出层位由西向东升高,具穿时性,越过了整个早奥陶世;2、Cruziana分布较广,而Skolithos较局限;3、Cruziana与Skolithos在时间上交替出现,而在贵州赫章县则只有Skolithos相。     

高家山生物群化石组合面貌及其特征

新元古代末期的高家山生物群 ,经系统研究自下而上可以划分为 3个化石组合带 ,即 :以蠕形动物爬迹为代表的 Shaanxilithes- H elminthopsis组合带 ;以锥管虫类和瓶状化石为主 ,并见大量软躯体蠕形动物和宏观藻类的Conotubus- Gaojiashania- Protolagena组合带 ;以多种管状骨骼化石共生为特征 ,并伴生有杯 (钵 )状、分枝管状及球状化石等的 Sinotubulites- Cloudina组合带 ,代表了高家山生物群鼎盛时期的产物。进一步的研究揭示高家山生物群是迄今为止地球上所发现的最早且最为多样化的骨骼化石组合。     

豫西焦作地区上石炭统浅海碳酸盐岩中的风暴沉积

焦作太原组灰岩存在至少四种类型的风暴沉积。类型A由下亚段正粒序分壳滞积层和上亚段生物扰动层组成,形成于风暴浪基面附近或之下;类型B由正粒序介壳滞积层、纹理层和痕迹层组成,形成于正常天气浪基面与风暴浪基面之间的下部环境;类型C由下亚段正粒序介壳滞积层和上亚段含少量痕迹化石的粒泥状灰岩组成,类型D仅由下部介壳滞积层和上部粒泥状灰岩组成,偶见痕迹化石,故类型C和D分别形成于正常天气浪基面之下和附近。     

中国首次发现奥陶纪无颌纲古鱼类动物群

2011年5~6月在新疆巴楚县一间房地区南1沟剖面上奥陶统恰尔巴克组首次发现百余件古鱼类化石。根据头甲具有一对眶孔和骨甲具有骨质层结构,将它们确定为无颌纲,并建立了新亚纲1个,新目2个,新科2个,新属新种各4个。鱼类化石赋存于熊剑飞等(2006)在该剖面所作的牙形石Baltoniodus alobatus带中,时代属于晚奥陶世艾家山期早期。根据外部形态特征将这一古鱼类化石群命名为秀丽巴楚鱼-宽吻古盔甲鱼(Bachuiaspis elegans-Palaeogaleaspis platyrostrastus Fauna)动物群。该化石动物群是中国脊椎动物生物证据确凿的记录,也是世界上晚奥陶世早期中国所特有的脊椎动物群。这批化石新材料的发现不仅在古鱼类发生和演化史上,而且在古脊椎动物地理分区和古构造分区上均具有重要的科学价值和研究意义。     

The H nuclear spin-lattice and spin-spin relaxation times at BEarth of some liquids associated with environmental spills

Assessing the extent of an environmental spill is the first step in soil remediation. Near-surface nuclear magnetic resonance (NMR) imaging is proposed as a possible technique for in situ imaging the extent of a spill because of the hydrogen or proton NMR signal associated with the most commonly spilled liquids. Before such a technique is developed, the available signal needs to be assessed. The hydrogen spin-lattice and spin-spin relaxation times of the spilled liquids are the best indicator of the signal. These relaxation times were measured for a variety of hydrocarbons that might be associated with spills. The relaxation times are measured at the Earth’s magnetic field, as these times are field dependent and a near-surface MRI will most likely operate at this magnetic field. With the exception of the more viscous hydrocarbons such as diesel fuel and motor oil, the lower viscosity liquids possess relaxation time values which should yield a good NMR signal from a near-surface MRI operating at the Earth’s magnetic field.     

New insights into the nature of the Late Riphean Eosolenides

Studies of a morphologically diverse population of Eosolenides, organic-walled macrofossils from the Upper Mesoproterozoic (1015–1025 Ma) Lakhanda Group of southeastern Siberia, suggest that these elongate fossils may be remains of soft-bodied organisms having tube-grade organization. The compressed, originally cylindrical fossils, of more or less constant diameter along their length, are subdivided by transverse membranes into a regular series of distinct chamber-like segments. The lateral walls of the segmented tubes are double-layered, the outer sheath- or cuticle-like layer of which was originally flexible and commonly exhibits very fine and closely spaced transverse striations. The presence of structures inferred to be basal attachment disks suggests a benthic habit, whereas the morphological variability of the population can be interpreted as showing that their body shape changed as the organisms grew and increased markedly in length. Reproduction may have been by budding. An important peculiarity exhibited by these tubular fossils is the presence within many specimens of small spherical unicells, interpreted possibly to be algal endosymbionts. Although in some respects these fossils resemble cnidarians, the biological affinities of Eosolenides tubes remain enigmatic.     

Geology, landscape and human interactions: examples from the Isle of Wight

The British Geological Survey has recently re-mapped the Isle of Wight at a scale of 1:10,000. This has added to a wealth of geological research already published. Within this paper, we highlight the importance of geology to the heritage of the Isle of Wight and its impacts on everyday life. There is a growing cultural awareness of the variety of landscapes and resources, the geology that underpins them, and the need to manage and understand them in a sensitive and sustainable way. ‘Geodiversity’, which collectively embraces these themes, is defined as “… the natural range (diversity) of geological (rocks, minerals, fossils), geomorphological (land form, processes) and soil features …” (Gray, 2004). This paper will focus on the geomorphological features; that is, the link between geology, the landscape it influences, and the human interactions with it. Examples from the Isle of Wight of the influences of geology on landscape include the landslides at Ventnor; geotourism at The Needles, Alum Bay and various dinosaur sites; and the artificial landscapes resulting from resource extraction. The geological issues and examples that we have used are some of the most applicable to everyday life, and therefore ones that many people will be able to relate to, such as geohazards (e.g. landslides), water supply, economic value (e.g. quarrying) and tourism. The paper is aimed at the non-specialist and students but also may provide a contextual element to professionals.     

由恐龙化石论晚白垩世事件沉积

本文根据晚白垩世恐龙化石的分布结合地层学特征,初步提出了这套含有恐龙化石的晚白垩世地层属于事件沉积的观点,并认为导致这次事件沉积的原因可能是由天体撞击地球产生的强海啸形成。     

Sodium and strontium in mollusc shells: preservation,palaeosalinity and palaeotemperature of the Middle Pleistocene of eastern England

This paper revisits the utility of sodium (Na) content in aragonite and calcite mollusc shells as an indicator of palaeosalinity. The data come mainly from a related suite of Middle Pleistocene marine and freshwater fossils that have been subject to broadly similar diagenetic histories. Environmental salinity is re-affirmed as the primary factor in determining the sodium content of modern and ancient mollusc shells: values <2000 ppm Na are generally indicative of non-marine environments while values >2000 Na ppm are typically from marine shells. There is a positive relationship between Na (salinity) and Sr which is a helpful discriminator of palaeosalinity in the fossil data set. The Na and Sr data give confidence that the fossil shells have not suffered pervasive diagenetic alteration and that the marine fossils lived in fully marine conditions. Oxygen isotope values in the best-preserved, fully marine fossil shells, suggest Middle Pleistocene ‘eastern England’ seawater temperatures were broadly similar to those of the modern North Sea.     

海绵动物骨针研究简介

海绵动物骨针是海绵动物骨骼的主要组成，是由生物矿化产生的；在地学研究中它是一种可用作地层对比的古生物化石。近年科学家发现了海绵骨针的光纤特性，特别是指出了这些特性可能引导人类开发新的光纤制造方法，从而引发了对其微结构、特性、生长机制与调控的生物学、生矿物学和仿生学的研究热潮。文章简介了海绵动物骨针的早期研究、光纤特性的发现及国内外研究概况。     

Preservation of borings: contrasting examples from the type Maastrichtian (Upper Cretaceous), southern Limburg,the Netherlands

The taphonomy of trace fossils and their substrates remains an understudied facet of sedimentary geology. Contrary to common prejudice, trace fossils are not invariably preserved in situ, but may be exhumed and reworked following lithification. The trace fossils most commonly found ex situ are borings in mobile shelly substrates. Two notable, but contrasting, examples of post-mortem transport of borings are described from the Maastrichtian (Upper Cretaceous) of southern Limburg, the Netherlands. A long, unusually straight and complete calcareous tube assigned to Teredolites longissimus Kelly and Bromley is an organically secreted internal mould, produced by a teredinid or pholadid bivalve boring in wood and lining their tube. Strictly, this is part of the body fossil of the producing bivalve, but it is also an organically generated internal mould of the boring. A flint steinkern of a right valve of Crassatella bosquetiana d’Orbigny preserves a suite of silicified borings. Caulostrepsis taeniola Clarke is a U-shaped boring with a vane connecting the parallel limbs. Talpina isp. is a slender, simple, branched tunnel. Most unexpected, Spirichnus spiralis Fürsich et al. is a spiral ‘worm’ boring hitherto only known from the Upper Jurassic. This stratigraphic gap is likely an artefact; only mouldic preservation of the bored substrate would expose the distinctive Spirichnus boring. These ichnofossils are united in their occurrence in unusual preservational systems.     

An Updated Review of the Middle-Late Jurassic Yanliao Biota: Chronology, Taphonomy, Paleontology and Paleoecology

The northeastern Chinese Yanliao Biota (sometimes called the Daohugou Biota) comprises numerous, frequently spectacular fossils of non-marine organisms, occurring in Middle-Upper Jurassic strata in western Liaoning, northern Hebei, and southeastern Inner Mongolia. The biota lasted for about 10 million years, divided into two phases: the Bathonian-Callovian Daohugou phase (about 168-164 million years ago) and the Oxfordian Linglongta phase (164-159 million years ago). The Yanliao fossils are often taphonomically exceptional (many vertebrate skeletons, for example, are complete and accompanied by preserved integumentary features), and not only are taxonomically diverse but also include the oldest known representatives of many groups of plants, invertebrates, and vertebrates. These fossils have provided significant new information regarding the origins and early evolution of such clades as fleas, birds, and mammals, in addition to the evolution of some major biological structures such as feathers, and have demonstrated the existence of a complex terrestrial ecosystem in northeast China around the time of the Middle-Late Jurassic boundary.     

Early Cambrian epibolic gastrulation: A perspective from the Kuanchuanpu Member, Dengying Formation, Ningqiang, Shaanxi, South China

The Cambrian explosion is marked by the apparent sudden appearance of diverse metazoan skeletal fossils and an increase in the complexity of both body and trace fossils. Among them, fossil eggs and embryos from the Lower Cambrian Kuanchuanpu Member of the Dengying Formation at Ningqiang in southern China provide a unique window for investigating the ontogeny of metazoans. Gastrulation is the cell migration stage after cleavage, and can be viewed as the embryonic analog of the transition from protozoan to metazoan grades of complexity. As an example, the embryonic developmental sequences of Punctatus emeiensis is well-documented because of the stellate spines covering the body surface, that are shared with embryonic stages represented by Olivooides and their growth stages represented by P. emeiensis. Although Olivooides was considered to be a taxonomic mixture, consideration of its variation was neglected. A specific type of embryo with zigzag blastopore lips that differs from typical candidate embryos for P. emeiensis is identified; its gastrulation process is reconstructed and is comparable to the epibolic gastrulation of extant metazoans. Both the embryos and adults of this ‘type’ display radial symmetry, that suggests an affinity distinct from that of echinoderms. Moreover, the body plan of penta-radial symmetry seen widely in Early Cambrian ‘Small Shelly Fossils’ (SSF's) was probably deep rooted in the Ediacaran.     

The First Observation on Plant Cell Fossils in China

For a long time, paleontologists have been focusing on hard parts of organisms during different geological periods while soft parts are rarely reported. Well-preserved plant cells, if found in fossils, are treated only as a rarity. Recent prowess in research on fossil cytoplasm indicates that plant cytoplasm not only has excellent ultrastructures preserved but also may be a quite commonly seen fossil in strata. However, up to now there is no report of plant cell fossils in China yet. Here plant cell fossils are reported from Huolinhe Coal Mine （the early Cretaceous）, Inner Mongolia, China. The presence of plant cytoplasm fossils in two cones on the same specimen not only provides further support for the recently proposed hypothesis on plant cytoplasm fossilization but also marks the first record of plant cytoplasm fossils in China, which suggests a great research potential in this new area.