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1.
Summary A new dasyclad alga—Acicularia boniae n.sp.—is discribed from Middle Triassic (?Ladinian) of the Piano del Minatore Formation, outcropping in the Cozzo del Pellegrino
area (Calabria, southern Italy). The systematic position of this species, with respect to the genusAcicularia and morphogeneraAciculella andTerquemella, is discussed.
Riassunto Viene descritta una nuova specie di dasicladale—Acicularia boniae—proveniente dal Triassico Medio della formazione del Piano del Minatore affiorante nel massiccio del Cozzo del Pellegrino (Calabria, Italia meridionale). Viene discussa la posizione sistematica rispetto al genereAcicularia ed ai morfogeneriTerquemella edAciculella.相似文献
2.
Dipl.-Geol. Gernot Arp 《Facies》1995,33(1):35-89
Summary The petrographic investigation of the Miocene Rieslake-carbonates gave rise to a modifiedDunham-scheme for classifying non-marine carbonates. If the fabric is not exclusively the result of hydromechanical or biogenic effects,Dunham-terms were extended by interpretative attributes describing processes responsible for the secondary fabric development (pedogenesis, early meteoric diagenesis). The lowermost investigated section reveals a distinct zonation of the lake shore during humid stages (carbonates of the infra-, eu-, and supralittoral), interrupted by playa-like interstages of arid conditions (desiccated mudflat). Dolomitic successions of sinter-veneered bioherms, built by green algae and cyanobacteria, form an incomplete ‘reef belt’ at the northern crater rim. Bioherm sequences were controlled by a seasonally oscillating lake level and fluctuations of higher order, which correspond to small-scale climatic fluctuations in the range of several hundreds to thousands of years. A superposed facies trend is recognized, which is the result of the decreasing eutrophy, alkalinity, and carbonate supersaturation. This reflects the climatic change to generally humid conditions at the end of Miocene. Originally thrombolitic sublacustrine spring mounds were caused by upwelling groundwater from permeable bedrock. Cement framestones of the mound core are considered to result from fabric alteration within the upwelling ground water and by emersions. Marginal carbonates of the Ries basin, inclusively bioherms, probably were originally Mg-calcitic. Aragonite was restricted to gastropod shells and sublacustrine spring mounds. Dolomitization is interpreted as essentially due to a fluctuating phreatic mixing-zone caused by meteoric groundwater, which underflowed saline water at the soda lake margin. The algal flora comprises cyanobacteria, possible cyanobacteria, green algae, few charophytes, endoliths, and problematic forms. A Recent contamination by endolithic fungi and lichens is evident. Occasionally preserved insect larval tubes, mass accumulations of pupal cases of flies, and arthropod eggs demonstrate that these groups were once a prominent part of the fossil soda lake ecosystem of the N?rdlinger Ries. 相似文献
3.
Reinhard Ziegler 《Geobios》2003,36(4):447-490
The bats from the karstic fissure fill sites Petersbuch 6, 10, 18, 31, 35 and 48 include 14 species, four of which are new. All samples are numerically dominated by rhinolophids, especially by Rhinolophus delphinensis. The rich samples from Petersbuch 6-18 are striking in their high species diversity (seven species each). Myotis bavaricus nov. sp. is characterised by a series of plesiomorphous characters, while Myotis reductus nov. sp. is more derived. A special trait of Submyotodon petersbuchensis nov. gen. nov. sp. is the coexistence of nyctalodont and (sub-) myotodont molars in one dentary. Miniopterus rummeli nov. sp. is characterised by its large size, a high coronoid process and its widely spaced lower premolars. Composition and origin of the chiropteran faunas are discussed. They are interpreted as an accumulation of bats that perished in the cave or rock crevice and to a negligible extent as remains of owl pellets. The stratigraphic correlation of the faunas, based on rodents, is late Middle Miocene (MN 7/8). This study is based on several thousand specimens. 相似文献
4.
Signatures of hydrocarbon venting in a Middle Devonian Carbonate Mound (Hollard Mound) at the Hamar Laghdad (Antiatlas, Morocco) 总被引:3,自引:0,他引:3
Dipl.-Geol. Jörn Peckmann Prof. Dr. Otto Heinrich Walliser Prof. Dr. Walter Riegel Prof. Dr. Joachim Reitner 《Facies》1999,40(1):281-296
Summary The Middle Devonian Hollard Mud Mound is situated in the eastern Hamar Laghdad, which is a small mountain range in the Tafilalt
in SE Morocco. In contrast to the well known Lower Devonian Kess-Kess mounds, the Hollard Mound is of Middle Devonian age.
The facies in the core of this mud mound differs from that of the other parts of the mound, and exhibits signatures of ancient
hydrocarbon venting. The carbonate phases of the core facies are derived from the oxidation of vent fluids and consist of
clotted micrite, a cryptocrystalline carbonate associated with spheres of uncertain origin, and a calcitic rim cement (rim
cement B). These vent carbonates show δ13C values in the range of −11 to −20% PDB indicating that some of their carbon is derived from isotopically light hydrocarbons.
Fossiliferous micrite has been affected by hydrocarbon venting in the proximity of the vent site, which is indicated by intermediate
δ13C values between vent carbonates and not affected sediments. Bivalves occur in dense populations within the core facies. They
form autochthonous shell accumulations and are almost exclusively articulated. it is likely that these bivalves were dependent
on chemosynthesis similar to their counterparts at modern vents. The vent deposits also exhibit an unusual prasinophyte assemblage,
which might have been linked to the specific nutrient availability at the vent site.
The ancient vent site is characterized by an enhanced carbonate precipitation and rapid lithification. The latter is corroborated
by the three-dimensional preservation of phytoplankton (prasinophytes and acritarchs) and the occurrence of stromatactoid
pores. An early phase of carbonate corrosion predating the formation of vent carbonates affected the fossiliferous micrite
of the core facies and is thought to be related to a phase of H2S-rich venting. 相似文献
5.
Dr. Jacek Matyszkiewicz 《Facies》1996,34(1):23-40
Summary In the top section of the Upper Jurassic profile in the S part of the Cracow-Wielun upland there occur deposits with numerous
fragments of the plantonic crinoidsSaccocoma. Sedimentary structures indicate that these deposits are calciturbidites with domination of the redeposited pelagic material.
TheSaccocoma-calciturbidites rest on the slope beds of Oxfordian cyanobacterial-sponge carbonate buildups formed in the Polish epicontinental
basin, bordering the Tethys ocean in the north. The occurrence of the planktonicSaccocoma seems to be connected with a short deepening the S part of the Polish epicontinental basin in the Late Jurassic. This deepening
caused the change within biocoenoses thriving in carbonate buildups and was mainly expressed in reducingTubiphytes. ‘Tubiphytes-reefs’, representing the last stage in the development of the carbonate buildups in the S part of the Cracow-Wielun upland,
marked the most shallow sedimentation environment. With deepending of the basin,Tubiphytes and other benthonic forms disappeared, and, simultaneously, the dominant fauna became planktonic. The abundance of planktonic
crinoidsSaccocoma (=Lombardia), as well as the presence of planktonic foraminifers, nannoplankton cf.Schizosphaerella, coccoliths and radiolarians indicates a pelagic, open-sea depositional environment.
TheSaccocoma-dominated sediments, which had been primarily deposited from a suspension on a sea floor with a distinct relief, became subsequently
transported by turbidity currents. A limited extent and thickness of theSaccocoma-calciturbidites was caused by a relatively small amount of the primary material which could be transferred by the turbidity
currents because the period of pelagic sedimentation was short. TheSaccocoma-calciturbidites indicate a distinct shift in conditions of sedimentation resulting from over-regional changes and, despite
the lack of index fossils, seem to represent a local lithostratigraphic horizon. These sediments probably mark a sedimentation
event which caused a minor levelling of the sea floor relief. Then, after a sedimentation break, wide-spread destruction of
the tops of carbonate buildups and formation of debris flows in the shallowing Late Jurassic sea took place.
TheSaccocoma-calciturbidites in the S part of the Cracow-Wielun upland can be found near edges of horsts. This suggests that the foundations
of these horsts are probably of sedimentary origin, dating back at least to the Late Jurassic. TheSaccocoma-calciturbidites in the S part of the Polish epicontinental basin seem to result from local, synsedimentary tectonic movements,
which probably reflect over-regional events on the one hand, and oscillations of the sea level-on the other. 相似文献
6.
A new specimen of the widespread Middle Jurassic to Lower Cretaceous Asian gonipholidid crocodilian genus Sunosuchus is described on the basis of a partial skeleton from the Upper Toutunhe Formation (Middle Jurassic, ?Bathonian-Callovian) of Liuhonggou, SW of Urumqi, Xinjiang Uygur Autonomous Region, People’s Republic of China. The specimen is represented by a partial mandible, teeth, vertebrae, limb and girdle bones and osteoderms. It can be distinguished from other nominal species of the genus by a unique combination of characters: slightly heterodontous dentition, strongly sculptured posteroventral part of the mandible, short fenestra mandibularis, convex dorsal surface of the retroarticular process, keeled cervical vertebral centra and ventral osteoderms with a distinctive sculpture of wide pits and narrow ridges. The heterodontous dentition is a potential autapomorphy of this form. The new specimen is closest in morphology to material described recently from the Callovian of Kirghisia as Sunosuchus sp. It represents the second Middle Jurassic record of the genus, the first crocodile from the Toutunhe Formation, the first substantial crocodile find from the Mesozoic of the Southern Junggar Basin, and the first Middle Jurassic record of Sunosuchus from China. This extends both the paleobiogeographical distribution of the genus in Asia and its stratigraphic distribution in China considerably. 相似文献
7.
Food and feeding habits of mud crab Scylla olivacea (Herbst, 1896) in Pichavaram mangroves was investigated quantitatively and qualitatively for a period of two years from June 2010 to May 2012. Gut contents from 1737 specimens comprising 843 males and 894 females in the size range between 45 mm and 148 mm were examined. Crustaceans form the predominant food item in a majority of size groups in terms of percentage wet weight and frequency of occurrence, while molluscs showed a preference in few size groups. The other dietary items includes fishes, detritus, mud and sand and miscellaneous. Gut content analysis revealed no significant variation between the quantities of food consumed by both sexes. Feeding intensity was higher in juveniles and subadults of both sexes than that of adults, revealing a greater preference to feed on fast moving prey such as crustaceans and fishes. The results of the present study indicate that S. olivacea in Pichavaram mangroves exhibited a clear preference for crustaceans. 相似文献
8.
Summary The development of peculiar margin facies and abundant talus breccias within the Dolomia Principale inner platform is commonly
observed in the Lombardy Basin during the Norian. The organisms building these margins are mainly serpulids, benthic microbes,
subordinate porostomata and other encrusting forms; typical margin organisms, as sponges or corals, are extremely rare or
absent. The build-ups form narrow rims along the borders of tectonic-controlled intraplatform basins. Regional back-stepping
and progradation of the margin facies on the talus breccias produced by the erosion of the reef is commonly observed in the
uppermost Dolomia Principale depositional system. Widespread occurrence of serpulids and microbial margins in middle-late
Norian times is indicative of stressed environmental conditions—fluctuation of salinity and temperature on the inner platform
and in the intraplatform basins—controlled by palaeogeographic setting. Physical characteristics allowed the bloom of forms
able to develop in a wide range of environmental conditions, such as serpulids.
In the Late Norian, major input of fine-grained clastics is recorded; close to the Norian-Rhaetian boundary, carbonate ramps
were regionally restored. Locally, small serpulid and microbial bioconstructions still persist in the lowermost part of the
shaly succession, even if they are less abundant with respect to the Dolomia Principale. Patch-reefs generally do not build
a platform margin, but represent isolated mounds within shaly deposits. These build-ups occur on the edge of former structural
highs; the communities survived the environmental change responsible for the siliciclastic input and locally managed to produce
mounds during the deposition of the lower part of the upper depositional system (Riva di Solto Shale). 相似文献
9.
Prof. Dr. Josip Tišljar M.Sc. Igor Vlahović Dr. Ivo Velić Dr. Dubravko Matičec Dr. Julie Robson 《Facies》1998,38(1):137-151
Summary During the Late Albian, Early and Middle Cenomanian in the NW part of the Adriatic Carbonate Platform (presentday Istria) specific depositional systems characterised by frequent lateral and vertical facies variations were established within a formerly homogeneous area, ranging from peritidal and barrier bars to the offshore-transition zone. In southern Istria this period is represented by the following succession: thin-bedded peritidal peloidal and stromatolitic limestones (Upper Albian); well-bedded foreshore to shoreface packstones/grainstones with synsedimentary dliding and slumping (Vraconian-lowermost Cenomanian); shoreface to off-shore storm-generated limestones (Lower Cenomanian); massive off-shore to shoreface carbonate sand bodies (Lower Cenomanian); prograding rudist bioclastic subaqueous dunes (Lower to Middle Cenomanian); rudist biostromes (Lower to Middle Cenomanian), and high-energy rudist and ostreid coquina beds within skeletal wackestones/packstones (Middle Cenomanian). Rapid changes of depositional systems near the Albian/Cenomanian transition in Istria are mainly the result of synsedimentary tectonics and the establishment of extensive rudist colonies producing enormous quantities of bioclastic material rather than the influence of eustatic changes. Tectonism is evidenced by the occurrence of sliding scars, slumps, small-scale synsedimentary faults and conspicuous bathymetric changes in formerly corresponding environments. Consequently, during the Early Cenomanian in the region of southern Istria, a deepening of the sedimentary environments occurred towards the SE, resulting in the establishment of a carbonate ramp system. Deeper parts of the ramp were below fair-weather wave base (FWWB), while the shallower parts were characterised by high-energy environments with extensive rudist colonies, and high organic production leading to the progradation of bioclastic subaqueous dunes. This resulted in numerous shallowing- and coarsening-upwards clinostratified sequences completely infilling formerly deeper environments, and the final re-establishment of the shallow-water environments over the entire area during the Middle Cenomanian. 相似文献
10.
Summary An integrated study of the early Messinian reef complex cropping out along the eastern coast of the Salento Peninsula (southern
Italy), including stratigraphy, facies analysis and paleoecological aspects, is here presented. Fourteen facies types belonging
to three main facies associations (back reef and shelf, shelf-edge, slope) have been recognized. They document a wide spectrum
of depositional environments, reef building organisms and growth fabrics, in response to depth and other environmental factors
in different parts of the reef complex.
The biotic structure of the reef is also described and discussed in detail. It consists of different types of reef building
organisms and of their bioconstructions (mainlyPorites coral reefs,Halimeda bioherms and vermetidmicrobial “trottoirs”), that differ in composition and structure according to their position on the
shelf edge-toslope profile.
Results indicate that the reef complex of the Salento Peninsula has strong similarities with the typical early Messinian reefs
of the Mediterranean region. However, the recognition of some peculiar features, i.e. the remarkable occurrence ofHalimeda bioherms and of vermetid-microbial “trottoirs”, gives new insights for better understanding reef patterns and development
of the reef belt during the Late Miocene in the Mediterranean. 相似文献
11.
Summary Published information and recent observation of physical and biogenic structures as well as grain size patterns along the East Frisian barrier islands (southern North Sea) have been synthesized to develop a facies model for a high energy, wave-tide-storm-influenced transgressive shoreface. As exemplified by Spiekeroog Island, three major shoreface facies (Upper, Central and Lower) are distinguishable, each of which can be subdivided into a Proximal and a Distal subfacies. A transgressive shoreface sequence in the rock record, in ascending order, will show the Upper Shoreface facies (USF) at the base. This is characterized by very well-sorted fine sands exhibiting predominantly plane lamination, which is consistent with its wave-dominated flow regime. The Central Shoreface facies (CSF) overlying the USF shows a high proportion of shells, a broad range of sediment sizes (fine sand to pebbles), and marked diversity in sedimentary structures. Graded storm beds, tidal cross-strata, mud-sand couplets, and horizontal to subhorizontal lamination are common. Swaley/hummocky (?) strata may also occur in its Distal subfacies. The sequence is topped by the Lower Shoreface facies (LSF). It consists mostly of bioturbated fine sands, although graded beds do occur. Distal sabfacies sands are consistently finer, better sorted, and more positively skewed than their Proximal counterpart. Anomalies in both coastwise and cross-shore textural trends are noted. In contrast to most other coastal settings, both fair-weather (wave- and tidal-current) and storm deposits are likely to be represented in subequal proportion in the rock record. 相似文献
12.
The Lower Cretaceous Pietraroia Plattenkalk is a fossiliferous, fine-grained cherty limestone from the Matese Mountains – Southern Apennines, Italy. The deposits are well known for the exceptional state of vertebrate fossil preservation. First considered as shallow lagoonal deposits or as intra-platform basin-fill, the Pietraroia Plattenkalk sequences are here interpreted as abandon deposits of a submarine channel (Pietraroia Channel) documenting a major transgressive event. Transgression was associated with the development of suboxic to anoxic conditions at the seafloor which favoured the preservation of fossils, as well as the deposition of coprolith-rich and bituminous layers. A peculiar paleogeographic and paleotopographic setting, which was strongly controlled by local tectonic, experienced the contiguity of wide emerged areas with a relatively deep-water channelised area where fossiliferous Plattenkalk sequences were deposited. 相似文献
13.
Anisian (middle triassic) buildups of the Northern Dolomites (Italy): The recovery of reef communities after the permian/triassic crisis 总被引:1,自引:0,他引:1
Dr. Baba Senowbari-Daryan Dipl. Geol. Rainer Zühlke Prof. Dr. Thilo Bechstädt Prof. Dr. Erik Flügel 《Facies》1993,28(1):181-256
Summary After the end-Permian crisis and a global ‘reef gap’ in the early Triassic, reefs appeared again during the early Middle Triassic.
Records of Anisian reefs are rare in the Tethys as well as in non-Tethyan regions. Most Anisian reefs are known from the western
part of the Tethys but there are only very few studies focused on biota, facies types and the paleogeographical situation
of these reefs. From the eastern part of the Tethys, Anisian reefs, reefal buildups or potential reef-building organisms have
been reported from different regions of southern China. Most of the Anisian reefs known from western and central Europe as
well as from southern China seem to be of middle and late Pelsonian age.
The study area is situated in the northern Dolomites (South Tyrol, Italy) southeast of Bruneck (Brunico). It comprises the
area between Olang (Valdaora) and Prags (Braies). The study is based on detailed investigations of the regional geology, stratigraphy
and lithofacies (R. Zühlke, T. Bechst?dt) as well as on a comprehensive inventory of Anisian reef organisms (B. Senowbari-Daryan,
E. Flügel). These data are used in the discussion of the controls on the recovery of reefs during the early Middle Triassic.
Most late Anisian reef carbonates studied are represented by allochthonous talus reef blocks of cubicmeter size. Small biostromal
autochthonous mounds are extremely rare (Piz da Peres). The reef mounds as well as most of the reef blocks occur within the
middle to late Pelsonian Recoaro Formation. They were formed on the middle reaches of carbonate ramps in subtidal depths,
slightly above the storm wave base with only moderate water energy. Most lithotypes observed in the reef blocks correspond
to sponge and/or algal bafflestones. Low-growing sessile organisms (Olangocoelia (sponge, alga?), sphinctozoan sponges, bryozoans, soleno-poracean algae, corals) and encrusting epibionts (sponges, porostromate
algae, cyanophycean crusts, foraminifera, worms, microproblematica) created low cm-sized biogenic structures (bioconstructions)
which baffled and bound sediment. Organic framework was only of minor importance; it is restricted to theOlangocoelia lithotype. Framework porosity was small in these reef mounds. Submarine carbonate cements, therefore, are only of minor importance
s compared with Permian or Ladinian reefs. The relatively high number of lithotypes encountered in the reef blocks indicates
a high biofacies diversity.
Regarding the relative frequency, the diverse biota consist in descending order ofOlangocoelia, sponges (sphinctozoans, inozoans, siliceous sponges), bryozoans, porostromate algae and worm tubes. The sphinctozoans are
characterized by small, mostly incrusting forms. The numerical diversity (species richness) is low compared with late Permian
or Ladinian and late Triassic sphinctozoan faunas occurring within reefs.
Following the sponges, monospecific bryozoans (Reptonoditrypa cautica
Sch?fer & Fois) are the most common organisms in the reef limestones. Porostromate algae were restricted to areas within the bioconstructions
not inhabited by sponges. The low-diverse corals had no importance in the construction of an organic framework.
Surprisingly, microbial crusts are rare or even lacking in the investigated Anisian bioconstructions. This is in contrast
to late Permian and Ladinian as well as Carnian reefs which are characterized by the abundance of specific organic crusts.
The same comes true for‘Tubiphytes’ which is a common constituent in Permian, Ladinian and Carnian reef carbonates but is very rare in the Anisian of the Olang
Dolomites. Instead of‘Tubiphytes’ different kinds of worm tubes (spirorbid tubes, Mg-calcitic tubes and agglutinated tubes) were of importance as epifaunal
elements. Macrobial encrustations consisting of characteristic successions of sponges, bryozoans, algae, worm tubes and microproblematica
seem to be of greater quantitative importance than in Ladinian reefs.
Destruction of organic skeletons (predominantly of bryozoans) by macroborers (cirripedia?) is a common feature.
The Anisian reef organisms are distinctly different from late Permian and from most Ladinian reef-builders. No Permian Lazarus
taxa have been found.
New taxa: Sphinctozoan sponges—Celyphia? minima n.sp.,Thaumastocoelia dolomitica n. sp.,Deningeria tenuireticulata n. sp.,Deningeria crassireticulata n. sp.,Anisothalamia minima n.g. n.sp., Inozoan sponges-Meandrostia triassica n.sp. Microproblematica-Anisocellula fecunda n.g. n.sp., Porostromate alga-Brandneria dolomitica n.g. n.sp.
Most of our data are in agreement with the model described byFois & Gaetani (1984) for the recovery of reef-building communities during the Ansian but the biotic diversity seems to be considerably
higher than previously assumed.
Anisian deposition and the formation of the reef mounds within the Pelsonian Recoaro Formation of the Dolomites were controlled
by the combined effects of synsedimentary tectonics and eustatic changes in sea-level. During several time intervals, especially
the early Anisian (northern and western Dolomites: tectonic uplift), the early Pelsonian (eastern Dolomites: drowning) and
the late Illyrian (wide parts of the Dolomites: uplift and drowning), the sedimentation was predominantly controlled by regionally
different tectonic subsidence rates. The amount of terrigenous clastic input associated with synsedimentary tectonics (tectonic
uplift of hinterlands) had a major influence on carbonate deposition and reef development. The re-appearance of reef environments
in the Olang Dolomites was controlled by a combination of regional and global factors (paleogeographic situation: development
of carbonate ramps; decreasing subsidence of horst blocks; reduced terrigenous input; moderate rise in sea-level). 相似文献
14.
广东贺江水域野生鲮鱼体表寄生虫典型海弯水虱的种群动态 总被引:1,自引:0,他引:1
近年来,广东贺江暴发了由等足类寄生虫引起的严重的鱼类外寄生虫病,给当地网箱养殖和野生鱼类资源造成了严重危害.根据虫体的口器、触角、腹肢等形态学特征将其鉴定为等足目(Isopoda)、扇肢亚目(Flabellifera)、纺锤水虱科(Aegid ae)、海弯水虱属(Alitropus)的典型海弯水虱(Alitropus typus).为了弄清典型海弯水虱对贺江内野生鱼类资源的危害及其种群季节动态变化规律,作者从2006年5月份到2 007年4月份,用刺网定时定点捕获野生鲮鱼(Cirrhina molitorella),检查典型海弯水虱的寄生状况.结果发现:典型海弯水虱对鲮鱼的感染率、感染强度和平均密度均从20 06年5月份开始上升,至7月份达到高峰,然后逐渐下降,于次年的2月份达到最低点,从3月份开始有所回升.典型海弯水虱种群在不同月份及不同体长鲮鱼中均为聚集性分布,且聚集强度随着平均密度的增加而增加.典型海弯水虱种群在鲮鱼中的感染参数与水温呈显著的正相关,而与宿主的体长无明显的相关性.周年种群结构动态变化分析表明: 典型海弯水虱 1年只繁殖1次,繁殖受水温的影响,6、7月份是其繁殖高峰期 [动物学报 5 4(3):407-415,2008]. 相似文献
15.
Marco Pavia 《Pal?ontologische Zeitschrift》2014,88(3):353-359
The occurrence of Archaeopsittacus sp. (Psittaciformes) in the fossil deposits of Sansan (France) is reported, testifying to a survival of this genus in the Middle Miocene, as Archaeopsittacus verreauxi was described from the Early Miocene of Saint-Gérand-le-Puy (France) and was recorded only from its type locality. The data discussed here indicate the presence of two parrot species from Sansan, as it is the type locality of another parrot species, Pararallus dispar, only known from this locality. The differences between the humeri of these two taxa are described in detail, together with the differences from the other European fossil parrot species. The presence of more than one species of parrot in the same locality is not rare, but in Europe it is recorded in Sansan for the second time. Evidence for parrots also confirms the paleoenvironmental reconstruction of Sansan, as parrots are primarily arboreal species. Archaeopsittacus also represents one of the few common elements between the Early and Middle Miocene European bird assemblages. 相似文献
16.
The succession of early species of the genus Kepplerites is established in the Upper Bathonian-Lower Callovian beds of Central Russia and compared with the ammonoid succession of East Greenland and Western Europe. Late Bathonian members of the genus Kepplerites from the Middle Volga Region are generally similar, though not identical to those from Greenland, whereas the Early Callovian Kepplerites species and their immediate Bathonian ancestors are represented by species common to all three regions. The analysis of the ammonoid distribution suggests a connection between the East Greenland and Central Russian marine basins in the Early and Middle Bathonian and in the Early Callovian, and their short-term isolation in the Late Bathonian. A new species, Kepplerites (Kepplerites) aigii sp. nov., is described from the Upper Bathonian (keuppi Zone) of the Alatyr River basin (Middle Volga Region). 相似文献
17.
Prof.Dr. Franco Russo Dr. Claudio Neri Dr. Adelaide Mastandrea Dr. Alberto Baracca 《Facies》1997,36(1):25-36
Summary The sedimentological features and the microbiofacies of the Cassian platforms (Late Ladinian-Carnian) of the Dolomites can be studied only on the basis of the socalled “Cipit boulders”, that are platform-derived olistoliths and clasts fed to the basin and escaped to the extensive dolomitization affecting the buildups. Our paper deals with the Cipit boulders occurring in the Punta Grohmann section (Wengen and S. Cassiano formations, Late Ladinian, Archelaus and Regoledanus Zones). The dominant microfacies are represented by boundstone, consisting of nearly 60% of micritic limestone occurring both as peloidal or aphanitic micrite, mostly organized into stromatolitic laminites of thrombolites. The skeletal organism (Tubiphytes, skeletal cyanobacteria, sphinctozoan sponges, etc.) represent only a minor component of the rock (usually less than 10%). Early cements are widespread and consist both of fan-shaped calcite (replacing former aragonite), bladed isopachous magnesian calcite and radial-fibrous calcite (neomorphic after Mg-calcite). The carbonate platforms from which the olistoliths derive were made up mainly of carbonate mud that underwent early lithification, as witnessed by the considerable amount of early cements: therefore they may be regarded to as mudmounds, and more precisely as microbial mud-mounds, due to the clearly accretionary, organic-controlled nature of most micrites. The micrites, subdivided into auto- and allomicrite on the basis of micromorphological and fabric characteristics, have been tested for epifluorescence. The results confirm the organic control on the deposition of automicrite, also in the cases in which a microbial influence is not obvious (i.e. aphanitic micrite without internal organization). 相似文献
18.
Pamela De Beer Kaufman 《American journal of physical anthropology》1977,47(3):409-414
The numbers of precoccygeal vertebrae (PCV) are compared in Southern African Negroes, Bushman (San) and American Negroes. The S.A. Negro and San males have an exceptionally high frequency of an increased total PCV number whilst the frequencies are significantly lower in a combined Caucasoid sample and the Mongoloid samples. The American Negro male, too, has a high frequency but not as high as in S.A. Negroes. The high frequency of increased PCV number in San, S.A. Negroes and American Negroes is in keeping with the view that the Khoisan peoples (here represented by the San), the Southern African Negroes and the African ancestors of American Blacks sprang from a common proto-negriform stock. Males have a significantly greater frequency of increased PCV to 30 or 31, whereas females are more likely to have a decreased number of 28 PCV. This sex difference is present in all the populations studied. 相似文献
19.
The Latemar is a mainly aggrading platform, but shows repeated backstepping during its entire development. The behaviour of the slope does not reflect accommodation changes and lateral consistencies of the lagoonal interior; the Latemar contemporaneously reveals different, even contrasting depositional characteristics. The slope of the late stage platform evolution corresponds at least partially to the base-of-slope apron model. Controlling factors on slope evolution are of tectonic (proximity of the Stava Line) and autocyclic (repeated oversteepening) nature. Other factors are insignificant and/or overprinted. The reef-facies at Latemar reveals a complex facies pattern; it varies along and across the margin and is rich in encrusting sponges, corals, biogenic crusts and Microproblematica. Some biota or fossil assemblages—e.g. foraminifers (Abriolina mediterranea, Turriglomina scandonei) or Tubiphytes multisiphonatus thrombolites—have not been described in the Dolomites before. Biostratigraphic evidence from the uppermost reef-facies confirms a mainly Anisian age of the outcropping platform interior. 相似文献
20.
Kang BJ Nanri T Lee JM Saito H Han CH Hatakeyama M Saigusa M 《Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology》2008,149(4):589-598
The mud shrimp, Upogebia major is a gonochoristic species with distinct sexual dimorphism; however, the male has the “ovarian part of testis” in the gonad and mature-looking eggs appear in a similar reproductive cycle to the female. Vitellogenesis of U. major was investigated focusing on the characterization of vitellogenin (Vg) gene expression and Vg processing. Vg cDNA cloned by PCR-based methods was 7799 bp-long, encoding 2568 amino acids in a single open reading frame. The deduced amino acid sequence shared common characteristics conserved in other shrimp Vgs. The Vg gene was expressed in the hepatopancreas of females and males, the ovary, and the ovarian part of testis. Vitellins (Vns) were detected in the gonads of both females and males as three prominent polypeptides with apparent molecular masses of 82 kDa, 100 kDa, and 115 kDa. N-terminal amino acid sequences determined for the three polypeptides were present in the deduced amino acid sequence, demonstrating that they derived from a single long Vg polypeptide. Immunoblot analysis using polyclonal antibodies raised against two Vns (82 kDa and 100 kDa) confirmed Vg processing in the hepatopancreas, in the hemolymph and possibly in the oocytes, similarly in both sexes. 相似文献