首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
A new genus and species of lightly sclerotized arthropod with an Aglaspis-like tagmosis, Kwanyinaspis maotianshanensis, is described from the well-known Chengjiang Lagerstätte, Early Cambrian, Yunnan, South China, on the basis of a single exquisitely preserved specimen. The dorsal exoskeleton, showing a poorly defined axial region but lacking axial furrows, is composed of a cephalic shield, 12 trunk tergites with well-developed pleural spines and a tail spine. A pair of ventral eyes is present beneath the first quarter of the cephalic shield. Appendages are preserved in remarkable detail; the basis is a large, flat plate, and bears gnathobases ventrally; the endopod is articulated with the abaxial edge of the basis and comprises seven articles; the exopod is flap-like and articulated along the entire length of the dorsal margin of the basis. Kwanyinaspis is provisionally assigned to Aglaspidida due to its overall resemblance to Aglaspis.  相似文献   

2.
Three new species of the Araucariaceae are described from leaf remains, Araucaria readiae from the Early Eocene Regatta Point flora, A. hastiensis from the Middle-Late Eocene Hasties flora, and Agathis tasmanica from the Early Oligocene-Early Miocene Little Rapid River flora. Additionally, emended diagnoses are presented for Araucarioides linearis and A. annulata. A. readiae is the first organically preserved species in the section Eutacta described from Tasmania, A. hastiensis is the first record of a species not in section Eutacta in Tasmania, and A. tasmanica is the first record of Agathis in Tasmania. These species, along with other records from south-eastern Australia indicate the presence of a high diversity of araucarian species in the region in the Early-Middle Tertiary, although no species survive there today. Climatic change and competition from angiosperms may have led to their demise in that region.  相似文献   

3.
Trilobites are common faunal elements in the Melbourne Formation, a unit of early Ludlow (upper nilssoni Biozone) age, which crops out extensively in the Darraweit Guim Province of the Melbourne Zone, central Victoria. New diagnoses are given for species previously described, including Maurotarion euryceps (McCoy, 1876; = Cyphaspis spryi Gregory, 1901), Raphiophorus jikaensis (Chapman, 1912; = Ampyx yarraensis Chapman, 1912), Cromus simpliciculus (Talent, 1964), Cromus spryi (Chapman, 1912), Sthenarocalymene kilmorensis (Gill, 1945; = Gravicalymene hetera Gill, 1945) and Trimerus harrisoni (McCoy, 1876). A new phacopid genus, Orygmatos is described, represented by the species O. yanyeani gen. et sp. nov. Other species newly described include Cromus melbournensis sp. nov., Arcticalymene australis sp. nov., “Ananaspis” woiwurrungi sp. nov. and Kettneraspis hollowayi sp. nov.

Species composition of the trilobite fauna varies spatially, and a number of distinct assemblages can be defined. Abundant trilobite moult configurations are conclusive for interpretation of the benthic fauna as autochthonous, inferring depth estimations based on benthic community distribution to be valid. A depth-related succession of communities is recognised and indicate the Melbourne Formation was deposited at relatively shallow depths on a broad, eastwardly deepening shelf, with deposition dominated by storm processes. The palaeoenvironment comprised a BA-1 community including the Arcticalymene australis trilobite assemblage, restricted to very shallow depths (~20 m) on the SW coastal margin of the shelf and preserved in proximal tempestite lithologies; and a BA-5 community group containing three distinct trilobite assemblages dominated by species of Cromus and a deeper water fauna, preserved in distal tempestite lithologies and ranging widely over the shelf at depths in the range of maximum storm wave base (~50 – 80 m).  相似文献   

4.
The musculature of the Recent Australian species, Magadina cumingi (Davidson 1852), is revised and previously unknown dorsal median pedicle muscles are described. The behaviour of M. cumingi is analysed in relation to the physical properties of the bryozoan sands it occupies on the Australian shelf. Functional morphology of a New Zealand Oligocene species, Rhizothyris amygdala Thomson 1920, indicates that this species would also have lived as a free and mobile form in the originally unconsolidated sediments (greensands) in which it is preserved. Shell characters of members of both Magadina and Rhizothyris are incompatible with an attached sedentary existence.  相似文献   

5.
A skull of a young specimen of Dipnorhynchus sussmilchi (Etheridge Jr), from the base of the Bloomfield Limestone Member (mid-Emsian, probably perbonus Zone) at Taemas, has both sides of the skull roof preserved, but the cheeks are missing. The posterior end of the endocranium, up to its dorsal extremity, provides new data on the endolymphatic sacs, and the attachment of the epaxial muscles. The endolymphatic region is compared with that of Chirodipterus australis. The palate is not fully formed and the marginal ridges are not fully developed. The fine structures around the dermopalatines and the pterygoids are preserved, indicating the manner in which the plates grew. The position of the parasphenoid is clearly outlined against the pterygoids, and confirms the view that this primitive genus of dipnoans did not have the pterygoids divided by the parasphenoid. All these features provide new information and comparison with Dipterus valenciennesi, the next oldest genus on which the same regions are preserved. In addition, a new mandible from a horizon low in the Cavan Bluff Formation is well preserved and provides information on the external bones of Dipnorhynchus.  相似文献   

6.
An ichnoassemblage of 10 ichnospecies is described for the first time from the Late Silurian Melbourne Formation at Studley Park, Victoria, southeastern Australia. The ichnofauna is preserved in a typical deep-water turbidite succession of alternating thin- to thick-bedded sandstone and thin- to medium-bedded mudrocks. Trace fossils observed within the study site have been assigned to three main ichnofacies. Ichnofacies 1 is best developed on the linguoid-rippled upper surface of thin sandstone beds and includes Laevicyclus, Aulichnites, Nereites, Helminthoidichnites, small Chondrites and possible Zoophycos. Ichnofacies 2 is very similar to Ichnofacies 1 in ichnospecies composition but instead contains large forms of Chondrites together with other thin burrow types usually poorly preserved and in very low abundance compared with Ichnofacies 1. Ichnofacies 3 is preserved mainly as casts on the underside of medium- to thick-bedded turbiditic sandstones, and has a very low diversity, with Planolites being the most common trace. A detailed analysis of the ichnofabrics and tiering structures of these ichnofacies suggest that Ichnofacies 1 and 3 represent ‘simple tiering’, in contrast to Ichnofacies 2, which is more characteristic of ‘complex tiering’. Despite the differences in ichnospecies composition and ichnofabrics between the three recognized ichnofacies, the collective ichnoassemblage from the study site can be assigned confidently to the Nereites ichnofacies and is, therefore, interpreted to have formed in a distal submarine fan environment of lower bathyal to abyssal depth. Further, it is possible to recognize two main subenvironments within this deep-sea setting to account for the differences between the ichnofacies. Ichnofacies 1 and 2 are interpreted to represent a typical Nereites ichnofacies located on a level basin floor subenvironment of relatively low energy conditions at the distal end of a submarine fan deposit. In comparison, Ichnofacies 3 is dominated by Planolites with rare other facies-crossing trace fossil forms, and lacks Nereites. It is, therefore, best interpreted as representing a relatively high-energy environment, possibly a distributary channel near the distal end of the submarine fan system.  相似文献   

7.
Early to Late Devonian (Emsian to late Famennian) organic walled microfossils were recovered from nineteen localities throughout the Tamworth Belt, northern New South Wales. The microfossil assemblages included poorly preserved chitinozoans and scolecodonts, spores and moderately well preserved foraminiferal linings. Fourteen species of foraminiferal linings from six genera are documented. At least three species of foramininferal linings (Inauris tubulata, Saccammina mea and Thurammina pustulosa) show potential for global correlation. Saccammina sp. cf. S. ampullacea and Thurammina mirrka may have application for correlation within Australia.  相似文献   

8.
Fourteen Bivalvia species are described from the Lower Permian Río Genoa Formation, exposed in the southern Tepuel-Genoa Basin (Chubut Province, Argentina), of which one, Fletcheripecten genoensis, is new. The studied specimens are well preserved, retaining fine details of the ornament and shell morphology. Palaeotaxodonta is represented by two species of Nuculopsis and four species of Phestia; Pteriomorphia by five species in five genera; and Heteroconchia by three informal species. Most of the species recorded also occur in the northern part of Tepuel-Genoa Basin and allow demarcation of new and distinct marine intervals in the Río Genoa Formation, which was classically interpreted to represent continental deposits. The bivalve fauna confirms a Cisuralian (Early Permian) age for the Río Genoa Formation and offers potential for improved regional and global correlations.  相似文献   

9.
Two papyrus fragments--now in the collection of the Oslo University Library--are described, transcribed and commented on in this publication. Both fragments belonged originally to a roll containing at least book 1 of Homer's Iliad. The handwriting is informal and rather careless, while the portion of the text preserved is of low textual standard. The above features suggest that the roll was a product of private scribal activity.  相似文献   

10.
Seven species of marine bivalves, including six new taxa, are described from the Cape early Miocene Melville Formation which crops out on the Melville Peninsula, King George Island, West Antarctica. The bivalve assemblage includes representatives of the families Nuculidae, Ennucula frigida sp. nov., E. musculosa sp. nov.; Malletidae, Neilo (Neilo) rongelii sp. nov.; Sareptidae, Yoldia peninsularis sp. nov.; Limopsidae, Limopsis psimolis sp. nov.; Hiatellidae, Panopea (Panopea) sp. cf. P. regularis; and Pholadomyoida (Periploma acuta sp. nov.). Species studied come from four sedimentary sections measured in the upper part of the unit. Detailed morphologic features of nucloid and arcoid species are exceptionally well preserved and allow for the first time reconstruction of muscle insertions as well as dentition patterns of Cenozoic taxa. Known geological distribution of the species is in agreement with the early Miocene age assigned to the Cape Melville Formation. The bivalve fauna from Cape Melville Formation is the best known from Antarctic Miocene rocks, a time of complex geologic, paleogeographic and paleoclimatic changes in the continent. The new fauna introduces new taxonomic and palaeogeographic data that bear on the question of opening of sea gateways and distribution of Cenozoic biota around Antarctica.  相似文献   

11.
12.
A new species of fossil wood is described, Bridelioxylon canningense Bamford & McLoughlin, belonging to the Phyllanthoideae group of the Euphorbiaceae. The woods occur in indurated sandstones and conglomerates preserved in palaeochannels incised into the Upper Permian Condren Sandstone in the Landrigan Cliffs, northern Canning Basin, Western Australia. Based on the presence of the dicotyledonous woods and the geomorphological setting of the palaeochannel, a Palaeogene age is suggested for the host rocks. This is the first record of fossil euphorbiacean wood in Australia; pollen has been previously recorded. The fossil wood is most closely comparable to extant members of Bridelia that currently occupy the warmer and wetter parts of Australia.  相似文献   

13.
The rostroconch mollusc Eopteria aiteneria sp. nov. is described from the Late Ordovician Angrensor Formation of north-eastern Central Kazakhstan; it is the first and only known representative of this group from the Ordovician of central Asia. By the beginning of the Late Ordovician Eopteria and the family Eopteriidae were on the verge of extinction and the new Kazakhstan species represents the youngest preserved record of the family in the Ordovician. It is likely that the group found a refuge in the diverse, but rather conservative, faunal assemblage of the Hiberno-Salairian type associated with Late Ordovician carbonate algal build-ups and mud mounds which spread widely during the late Caradoc to mid Ashgill across Kazakhstanian volcanic island arcs and microplates.  相似文献   

14.
Bodnar, J., June, 2008. Rhexoxylon cortaderitaense (Menéndez) comb. nov., a species of permineralized stems newly assigned to the Corystospermaceae, from the Triassic of Argentina. Alcheringa 32, 171–190. ISSN 0311-5518.

Anatomically preserved stems of Late Triassic corystosperms from the upper Cortaderita Formation in San Juan province, Argentina are described and assigned to Rhexoxylon cortaderitaense (Menéndez) comb. nov. These specimens were originally attributed to conifers, a group not closely related to corystosperms. The silicified axes preserve features of the cortex, pith, and secondary vascular system. Like all Rhexoxylon species, these axes have two discontinuous cambial rings that develop centrifugal secondary xylem (normal secondary xylem) and centripetal secondary xylem (inverted secondary xylem). Both types of xylem are separated by a band of parenchymatous tissue developed by a remnant cambium. The centrifugal xylem is divided by parenchymatous rays following differential cambial activity. The secondary xylem is pycnoxylic with uniseriate rays; tracheids have mainly biseriate and alternate bordered pits on radial and tangential walls, and one simple oval pit in cross-fields. The distinctive feature of R. cortaderitaense is the conspicuous amount of centripetal secondary vascular tissues not forming perimedullar bundles, this being interpreted as an apomorphic trait. This interpretation of the character modifies previous hypothesized phylogenetic relationships of corystosperm wood taxa.  相似文献   

15.
Brea, M., Zamuner, A.B., Matheos, S.D., Iglesias, A. & Zucol, A.F., December, 2008. Fossil wood of the Mimosoideae from the early Paleocene of Patagonia, Argentina. Alcheringa 32, 427–441. ISSN 0311-5518.

An anatomically preserved mature stem from the Salamanca Formation (early Paleocene) at Palacio de Los Loros, central Patagonia, Argentina, is described and assigned to Paracacioxylon frenguellii sp. nov. The material was preserved by siliceous permineralization and shows features of the secondary xylem typical of subfamily Mimosoideae. This species represents the oldest record of the genus and of the Leguminosae along the western border of Gondwana, and is the world's second oldest record of Leguminosae wood. The species is characterized by ring-porous to semi-ring-porous vessels that are solitary, in multiples of 2–4 and clustered, simple perforation plates, alternate and vestured inter-vessel pitting, homocellular 1–6 seriate rays, tyloses, crystals and diffuse apotracheal, vasicentric paratracheal and confluent axial parenchyma. Paracacioxylon frenguellii has anatomical similarities to Acacia Miller. The presence of Paracacioxylon frenguellii associated with pulvinate leaves suggests that the legumes might have been a component of mesothermal forests developed along the western margin of the Golfo San Jorge Basin during the early Paleocene.  相似文献   

16.
ABSTRACT

Among the extra-biblical texts from Qumran we find the so-called Aramaic Levi, which can be described as a somewhat different variant of the “Testament of Levi,” a part of the larger Greek text “The Testament of the Twelve Patriarchs.”

Aramaic Levi, however, was already known from the Cairo Genizah. The following article is a linguistic comparison between the Qumran text and the version from the Cairo Genizah.

As Klaus Beyer has noticed, there are a lot of non-Hasmonean spellings and words in the Genizah text, but most of Beyer’s examples are from parts of the text that are not preserved in the Qumran fragments. Comparing the two versions, we now note that the deviations are of two kinds. As expected, the Genizah text often follows a later language than Qumran. This applies in particular to orthographic features and the use of status emphaticuswithout the definite sense. But in other places the Genizah text represents a language older than Hasmonean Aramaic, which we interpret as an adaptation to Bibli-cal Aramaic and sometimes to Hebrew.  相似文献   

17.
Phosphate fillings of the tunnels made by endolithic micro-organisms in the shells of Early Cambrian molluscs have been observed on phosphatic internal moulds at several sites. The best preserved examples are from the shells of the gastropod Yuwenia bentleyi from the Parara Limestone of South Australia. Three distinct types of borings are found in these shells: long unbranched tunnels that are either about 10 µm or 3 µm in diameter, and short vertical holes. The nature and distribution of the borings suggest that they were made by photosynthetic algae rather than fungi.  相似文献   

18.
Artabe, A.E. & Zamuner, A.B., March 2007. Elchaxylon, a new corystosperm based on permineralized stems from the Late Triassic of Argentina. Alcheringa 31, 85‐96. ISSN 0311-5518.

Anatomically preserved stems of Late Triassic corystosperms from the Río Blanco Formation of Argentina are described and assigned to Elchaxylon zavattieriae gen. et sp. nov. The polyxylic gymnospermous axes have two discontinuous cambial rings, which develop centrifugal secondary xylem and centripetal secondary xylem around the mesarch primary xylem bundles. The centrifugal undivided pycnoxylic secondary xylem incorporates uniseriate rays, uni- to biseriate radial pitting either alternate or opposite, and one or two simple pits in each cross-field. Atypical secondary growth is restricted to localized development of centripetal secondary xylem (inverted xylem). Elchaxylon could represent a basal member of the rhexoxyloid lineage. This basal clade is characterized by limited centripetal secondary xylem, lack of perimedullar bundles, and modest development of centrifugal xylem.

Analia E. Artabe [aeartabe@museo.fcnym.unlp.edu.ar] and Alba B. Zamuner [azamuer@museo.fcnym.unlp.edu.ar]. División Paleobotánica, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, Paseo del Bosque SN, 1900 La Plata, Argentina and Consejo Nacional de Investigaciones Científicas y Técnicas; received 20.5.2005, revised and accepted 14.9.2005.  相似文献   

19.
《英国考古学会志》2013,166(1):165-167
Abstract

Wooden Madonna tabernacles from c.1150–c.1350 are today scarce, and it is therefore difficult to get a complete understanding of their original appearance and variations. Nevertheless there are still preserved at least fifteen Madonna tabernacles, or substantial fragments of them, in Scandinavia, which can give us a picture of the variety of appearance and form these large tabernacles had in this period. The surviving Scandinavian Madonna tabernacles have, like the southern European ones, quite a lot of variation in types and appearance, both in their closed and open positions. The largest group consisted of niches with relief-figures on the interior when open, but the scenes could also be painted, or painting and sculpture combined on the same surface. A neglected aspect of these tabernacles is their appearance in the closed position. Often the wings of the tabernacles have their original painting preserved on the exterior, even if the reverse has been overpainted or the wings have been restructured. Many of these original surfaces had non-figural decoration, such as foliage, monochrome surfaces in red or green, or a combination of simple patterns of red and green.  相似文献   

20.
Abstract

Excavations of the southern part of a very rich sacri?cial bog in Illerup Ådal, Denmark between 1950 and 1985 recovered approximately 15,000 Iron Age artefacts. At the time, 60 per cent of the area was left unexcavated and thousands of objects are now preserved in situ, but the present preservation status has not been investigated for approximately twenty-?ve years. Extensive in situ monitoring was carried out for one year in order to present a prioritized plan for further monitoring of the unexcavated areas, producing documentation of groundwater table variations, water quality and vegetation in the area. Results show that the remaining artefacts are generally well preserved in a waterlogged and anaerobic environment. However, in the north-eastern part of the bog, the groundwater table is too low even in a year when net precipitation and hydrological conditions were near normal. In the centre of the bog elevated salt concentrations have been measured in the groundwater.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号