首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   104篇
  免费   2篇
  2020年   3篇
  2019年   4篇
  2018年   2篇
  2017年   8篇
  2016年   6篇
  2014年   1篇
  2013年   51篇
  2012年   6篇
  2011年   4篇
  2010年   3篇
  2009年   2篇
  2008年   3篇
  2007年   2篇
  2006年   3篇
  2003年   1篇
  2002年   2篇
  2000年   1篇
  1994年   1篇
  1990年   1篇
  1989年   1篇
  1987年   1篇
排序方式: 共有106条查询结果,搜索用时 15 毫秒
1.
Considerable progress has been made in recent years in the study of the Lower and Middle Paleolithic of northern Asia. There is growing evidence for initial human occupation before 700,000 years ago—as early as elsewhere in Asia—and for a very early adaptation to the arctic desert environment. New models of Lower Paleolithic settlement involve expansion and reduction of occupation in response to climatic variation, rather than simple colonization followed by steady occupation. The Middle Paleolithic of northern Asia is better documented, including actual finds of archaicHomo sapiens. The transition to the Upper Paleolithic seems to involve the survival of earlier cultural traits, but the mechanisms and processes are not well understood. Further significant knowledge concerning these periods awaits the development of common methodologies for classification and analysis.  相似文献   
2.
VandenBerg, A.H.M. & Maletz, J., April 2016. The holotype of Pseudisograptus manubriatus manubriatus (Hall, 1914)—implications for the identification of Pseudisograptus manubriatus subspecies. Alcheringa 40, xxx–xxx. ISSN 0311-5518

The holotype of Pseudisograptus manubriatus manubriatus (Hall, 1914) has been rediscovered in the collections of Museum Victoria and is recognized to belong to Pseudisograptus manubriatus harrisi as described by Cooper & Ni (1986). This taxon becomes a junior synonym of P. m. manubriatus. The selected neotype of Pseudisograptus manubriatus manubriatus (Hall, 1914) can be referred to Pseudisograptus manubriatus texanus Cooper & Ni, 1986. The proximal development in all known relief specimens of Pseudisograptus and their descendants indicates that a symmetrical development of the manubrium must be regarded as the rule, and the interpretation of a strong asymmetry in Pseudisograptus manubriatus texanus is rejected.

Alfons H.M. VandenBerg [, ], Geology, Museum Victoria, GPO Box 666, Vic 3001, Australia; Jörg Maletz [], Department of Earth Sciences, FU Berlin, Malteserstrasse 74-100, D-12249 Berlin, Germany.  相似文献   
3.
Lu, J.-F., November 2015. Morphological analysis of Ozarkodina prolata Mawson and Ozarkodina midundenta (Wang & Ziegler) (Emsian conodonts) from South China. Alcheringa 40, xxx–xxx. ISSN 0311-5518.

Investigations of conodonts from Emsian (Lower Devonian) strata at Bahe, Liujing and Daliantang in Guangxi and Yunnan, South China, provide new data on the morphological variability and phylogenetic affinity of Ozarkodina midundenta, a species initially assigned to Pandorinellina but transferred to Ozarkodina herein. Morphological analysis suggests that O. midundenta probably developed from O. prolata by progressive fusion of denticles in the middle third of the blade above the basal cavity in the Pa element.

Jian-feng Lu [], Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, PR China. Also affiliated with University of Chinese Academy of Sciences, Beijing 100049, PR China.  相似文献   

4.
In the late 1980s, a collaborative effort between Harvard University’s Lower Mississippi Survey and Tulane University’s Center for Archaeology launched a study examining the causes and consequences of subsistence change in the Lower Mississippi Valley. The Osceola Project contributed the first formal study of late prehistoric faunal remains within the Alluvial Plain, becoming the standard against which all subsequent Coles Creek faunal assemblages have been measured. Recent evidence recovered from three sites located in the Eastern Uplands presented the opportunity to compare and contrast vertebrate subsistence in these two distinct physiographic regions. We hypothesize that a clear distinction exists between lowland and upland Coles Creek procurement strategies. This article evaluates this claim by examining species diversity, spatial patterns, and temporal trends evident within an eight-site sample. The results suggest that the primary factor influencing Coles Creek fauna procurement was the immediate environment, and that the composition of Late Woodland period diets may be a reflection of efficiency of effort rather than food access or scarcity.  相似文献   
5.
This article describes alterations to equid lower second premolars and diastemata from a series of known life history equids and a number of archaeological horse specimens from the British Iron Age. Two new methods for recording bit wear are proposed involving the analysis of the extent and morphology of enamel/dentine exposure on the anterior edge of LP2s and analysis of the extent of new bone formation and bone loss to the diastema of the mandible. It is suggested that when a bit is used on a horse it acts more frequently on the anterior margin of the LP2 than has previously been thought and that repeated contact between the bit and the LP2s and diastemata results in recognisable damage to these areas of the mouth.  相似文献   
6.
Lee, D.-C. February 2017. Radialimbricatus, a new ichnogenus from the lacustrine sandstone facies of the Lower Cretaceous Jinju Formation, South Korea. Alcheringa XX, XXX–XXX.

The trace fossil Radialimbricatus igen. nov. with type species of R. bitoensis isp. nov. occurs in river-mouth-bar sandstone beds of a lacustrine sequence of the Lower Cretaceous Jinju Formation in South Korea. Radialimbricatus is a horseshoe-shaped or elliptical, convex hyporelief structure characterized by imbrication of traces with radial ridges and a median furrow. These features differentiate Radialimbricatus from arthropod ichnofossils such as Rusophycus and Cruziana, possibly cnidarian ichnofossils such as Astropolichnus and vermiform organism ichnofossils such as Oldhamia. Cross-sectional features of R. bitoensis, including upward mud protrusions at lateral margins, demonstrate that R. bitoensis can be formed as an open epigenic furrow at the water/mud interface or an endogenic burrow along the sand/mud interface at the same time. Analysis of discrete and imbricating horseshoe-shaped traces indicates that the tracemaker maintained an obligate inclined posture even when forming trails. The radial ridges and pit along the median furrow are interpreted to reflect feeding behaviour, and the imbrication to result from unidirectional and more or less regular movements to next feeding sites. The tracemaker is thought to have been an organism with an elliptical body outline, radially arranged body parts at the base of or around the body (probably for collecting and transporting foods and moving to feeding sites) and a mouth near the centre of the body, which is consistent with body plan features of arthropods, cnidarians and annelids.

Dong-Chan Lee [], Department of Earth Sciences Education, Chungbuk National University, Cheongju, 28644, South Korea.  相似文献   

7.
Zhen, Y.Y., Wang, G.X. &; Percival, I.G., August 2016. Conodonts and tabulate corals from the Upper Ordovician Angullong Formation of central New South Wales, Australia. Alcheringa 41, xxx–xxx. ISSN 0311-5518.

The Angullong Formation is the youngest Ordovician unit exposed in the Cliefden Caves area of central New South Wales. Its maximum age is constrained by a Styracograptus uncinatus graptolite Biozone fauna at the very top of the underlying Malongulli Formation, but the few fossils previously reported from higher in the Angullong Formation are either long-ranging or poorly known. From allochthonous limestone clasts in the middle part of the formation, we document a conodont fauna comprising Aphelognathus grandis, A. solidum, Aphelognathus sp., Aphelognathus? sp., Belodina confluens, Drepanoistodus suberectus, Panderodus gracilis, Panderodus sp., Phragmodus undatus, Pseudobelodina inclinata and Pseudobelodina? sp. aff. P. obtusa, which supports correlation with the Aphelognathus grandis Biozone (late Katian) of the North American Midcontinent succession. The species concepts of Aphelognathus and Pseudobelodina are reviewed in detail. Associated corals are exclusively tabulates, dominated by agetolitids, including Agetolites angullongensis sp. nov., Heliolites orientalis, Hemiagetolites breviseptatus, Hemiagetolites sp. cf. H. spinimarginatus, Navoites sp. cf. N. circumflexa, Plasmoporella bacilliforma, P. marginata, Quepora sp. cf. Q. calamus and Sarcinula sp. Affinities of the coral fauna from the Angullong Formation are closer to faunas from northern NSW and northern Queensland than to the locally recognized Fauna III of late Eastonian age in central NSW. We propose a subdivision of Fauna III to account for this difference, with the late Katian Fauna IIIB characterized by the incoming of agetolitid corals. The currently known distribution of representatives of this group with adequate age constraints suggests that agetolitids possibly originated in North China, subsequently migrating to Tarim, South China and adjacent peri-Gondwanan terranes while also spreading eastward to northern Gondwana, where they progressively moved through eastern Australia to reach the central NSW region by the early Bolindian.

Yong Yi Zhen* () and Ian G. Percival (), Geological Survey of New South Wales, W.B. Clarke Geoscience Centre, 947953 Londonderry Road, Londonderry, NSW 2753, Australia; Guangxu Wang (), State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, 39 East Beijing Road Nanjing 210008 PR China.  相似文献   
8.
9.
Nadung’a 4 is one of the single carcass pachyderm sites recorded in East Africa during the Lower and Early Middle Pleistocene. The site has yielded an abundant lithic assemblage in close association with the partial carcass of an elephant. Conjoined pedological, geoarchaeological, spatial, technological, and taphonomical analyses have been carried out to address the relationship between hominids and elephant. The resulting data are consistent with a non-fortuitous association between both categories of remains. The lithic artefacts do not match a classical Acheulean tool-kit, as would be expected for the time period ascribed to the site, and the functional patterns inferred from their analysis make this site radically different from other purported butchery sites. The implications of these original features are discussed.  相似文献   
10.
2006年,对内蒙古赤峰市康家湾遗址进行发掘。该遗址以夏家店下层文化遗存为主体,遗迹有房址、墓葬、灰沟、灰坑、灶等,出土较多陶器、石器、蚌器、骨器等。该遗址不属于石城址,房址均为土坑半地穴式。它的发现,为研究阴河中下游地区夏家店下层文化的聚落形态及建筑形式提供了重要资料。  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