湖北丹江口早始新世梳趾鼠类一新属及伴生哺乳动物化石

描述了湖北省丹江口市均县镇一始新世化石点的3种哺乳动物化石,其中包括梳趾鼠类一新属种：林氏汉南鼠（新属、新种）Hannanomys lini gen. et sp. nov.。根据林氏汉南鼠与其他梳趾鼠类性状对比及该地点动物群组合特点推测其时代为早始新世晚期,与产于玉皇顶组中段的王家营大尖地方动物群的时代相当。该化石点是李官桥盆地中汉江南岸早始新世化石地点的首次发现,它的认定对在此地区寻找古新统/始新统界线有重要意义。     

秦岭东段李官桥盆地始新世哺乳动物化石新材料

李官桥盆地是始新世地层发育较全、哺乳动物化石丰富的盆地。本文报道了该盆地两个始新世化石新地点,哺乳动物共计4目7属8种。其中有5个新种,分别为Kuanchuanius? danjiangensis sp. nov.、Asiocoryphodon progressivus sp. nov.、Gobiatherium minutunz sp. nov.、Lophialetes? primus sp. nov.、Eomoropus? zhanggouensis sp. nov.。动物群的时代可能为中始新世早期。     

“化石金矿”的发现

在美国西部怀俄明州广袤的干旱地区,在几千万年前的新生代的早期曾经是各种脊椎动物大量繁衍的地区。该州有不少著名于世的盆地,盛产各类脊椎动物化石。文德瑞弗尔盆地就是其中之一。该盆地主要出露的地层是始新世的沉积物,其上部地层是桔红色的“莱塞特组”,在该组地层中曾发现大量哺乳动物化石,其下部为绿灰色文德瑞弗尔组,长期以来累有化石发现。自1980年以来,宾夕法尼亚州的卡     

河南、山西晚始新世哺乳类化石地点与化石层位

始新世晚期的哺乳类化石层位是我国发现化石种类最丰富、研究工作做得最多的早第三纪脊椎动物化石层位之一,而河南西部和山西南部产晚始新世哺乳类化石的地层,是我国除内蒙二连地区外在这方面研究最早和发现化石最多的一个地区。但是,有关这一地区主要含化石的地层和化石地点的资料,大多比较零散,而且有一些错漏之处,需要补充、修订和从地层及生物群方面进行归纳。本文的主要内容和目的是:(1)河南卢氏盆地始新统卢氏组剖面的描述、化石地点与发现的脊椎动物属、种名单及其动物群性质的讨论。(2)关于河南、山西间黄河岸边“垣曲盆地”始新世、渐新世哺乳动物化石地点的分布、层位和时代方面的修订和补充资料。(3)河南济源的晚始新世哺乳类化石地点述要。     

晚中新世晚期土城子小哺乳动物组合及土城子动物群在内蒙古中部地区新近纪哺乳动物群序列中的位置（英文）

近百年来,在内蒙古中部地区发现了丰富的新近纪哺乳动物化石,命名和描述了10余个哺乳动物群,其时代跨越早中新世至早上新世。它们已经成为建立中国北方新近纪哺乳动物生物年代地层框架的重要依据。早在1959年中苏古生物联合考察过程中就已经发现土城子地区有丰富的哺乳动物化石,但这些化石以大–中型哺乳动物为主,缺乏小哺乳动物。土城子动物群的构成和其在中国北方新近纪哺乳动物年代地层框架中的位置长期以来不是特别明确。报道了在土城子新发现的6种小哺乳动物化石。根据Lophocricetus grabaui–Sinocricetus zdanskyi–Prosiphneus licenti–Hansdebruijnia pusilla–Moschus grandaevus的组合特点,认为土城子动物群的年代应该可以很好地约束在晚中新世(或者保德期)的晚期。土城子动物群明显比内蒙古的宝格达乌拉动物群要进步一些,与二登图动物群非常相似,时代上晚于前者,略早于后者。依据动物群整体面貌,推测在晚中新世晚期土城子地区存在森林和草原混合的环境。     

新疆吉木乃地区始新世中期哺乳动物化石1)

记述了新疆吉木乃地区托斯特西部发现的Triplopus sp.、 Triplopus? jeminaiensis sp.nov., Lophialetes sp.及Hyaenodontidae indet.等哺乳动物化石,证实了这一地区中始新世地层的存在.其属种构成大致可与内蒙古伊尔丁曼哈动物群及哈萨克斯坦中始新世Obayla或Sargamys哺乳动物群对比,时代为伊尔丁曼哈期.     

新疆吉木乃地区始新世中期哺乳动物化石

记述了新疆吉木乃地区托斯特西部发现的 Ｔｒｉｐｌｏｐｕｓ ｓｐ．、 Ｔｒｉｐｌｏｐｕｓ？ ｊｅｍｉｎａｉｅｎｓｉｓ ｓｐ． ｎｏｖ．、 Ｌｏｈｉａｌｅｔｅｓ ｓｐ．及Ｈｙａｅｎｏｄｏｎｔｉｄａｅ ｉｎｄｅｔ．等哺乳动物化石,证实了这一地区中始新世地 层的存在。其属种构成大致可与内蒙古伊尔丁曼哈动物群及哈萨克斯坦中始新世Ｏｂａｙｌａ或 Ｓａｒｇａｍｙｓ哺乳动物群对比,时代为伊尔丁曼哈期。     

云南昭通中新世末期鸟类动物群的组成及其时代意义北大核心CSCD

近年来,作者等人曾在云南昭通地区进行了多次野外大型化石发掘工作,在昭通组含褐煤的组合层中出土了大量的脊椎动物化石,其中以鸟类化石为最多,初步鉴定约860余件。经统计,这些鸟类分属于11目18科。此外,一同产出的还有鱼类、两栖类、爬行类,哺乳动物中的灵长类、长鼻类、奇蹄类、偶蹄类、食肉类、啮齿类、兔形类等化石,它们共同组成了一个新近纪早期(中新世末期)西南地区以鸟类为主的脊椎动物化石群。另外,从20世纪至今,在昭通组的时代界定上,长期以来观点尚不统一。文中根据新发现的动物群,特别是小哺乳动物的最新分析研究,结合古地磁测定结果,推测该动物群的年代应为中新世末期,较之以前的上新世—早更新世的时代结论大大提前。同时,昭通地区中新世鸟类动物群的发现,不仅填补了这一时期我国鸟类化石群的空白,而且对于新近纪鸟类演化的研究也具有重要意义。     

内蒙古中部新近纪动物群的演替与生物年代

内蒙古中部地区陆相新近系出露广、含化石丰富。对这一地区新近纪的研究,可以追溯到20世纪初期瑞典地质学者安特生(J．G．Andersson)、法国古生物学者德日进(P．Teilhar de Chardin)和以美国探险家安德鲁斯(R．C．Andrews)为首的美国自然博物馆中亚考察团分别对二登图、高特格和通古尔的考察与化石采集。他们的开拓性工作使这些地方成为中国十分重要的新近纪经典地点。特别是通古尔,由于其产出的化石丰富、具有中中新世动物群的特征, 已引入中国地质年表,作为新生代中一个“阶”的名称。最近20多年对这一地区新近纪生物地层学的研究又取得了很大的进展,新发现了数个不同时代的化石地点和层位,同时采集到大批哺乳动物化石标本。内蒙古中部各地点化石层的厚度一般不大,但所含的哺乳动物化石种类多、材料丰富。由于具有这一特点,使其化石组合能比较接近地反映短期内动物群体的结构面貌,较客观地指示沉积时期的生态环境。利用这些组合进行动物群相对时代的确定,以及对其生态环境的恢复无疑都会很有意义。但是,这里的地层缺乏测试绝对年龄的材料,化石组合间少见有直接的叠置关系,使得在这一地区建立独立的动物群时间顺序,确定动物群的演替序列和生物年代只能更多地依赖于对动物系统发育和动物群体变化的研究。本文对这一地区各地点发现的哺乳动物化石组合进行了审定,提供了最新的动物群名单;根据默尔根地点上部层位产出的化石组合特征,提议把该组合命名为铁木钦动物群;通过对哺乳动物系统发育关系的分析,将动物群进行先后排序,并阐述了这些动物群在各生物年代的演替特征;同时展示了各动物群与有关岩石地层和磁性地层的关系。文中进一步认定了苏尼特左旗的嘎顺音阿德格动物群为内蒙古中部地区现知新近纪动物群中的最早代表,其后依次为推饶木动物群、默尔根动物群、铁木钦动物群、阿木乌苏动物群、沙拉动物群、宝格达乌拉动物群、二登图动物群、哈尔鄂博动物群、比例克动物群、高特格动物群。内蒙古中部被认为是新近纪生物年代学研究的重要地点,在地质时代上这一哺乳动物群系列跨越了新近纪中新世至上新世的大部分时段。其中的嘎顺音阿德格动物群具有中国陆生哺乳动物年代山旺期的典型持征;推饶木动物群、默尔根动物群、铁木钦动物群构成的广义通古尔动物群,正是定义东亚中中新世陆生哺乳动物年代的依据;阿木乌苏动物群、沙拉动物群、宝格达乌拉动物群和二登图动物群符合保德期动物群的含义;比例克动物群和高特格动物群具有榆社期动物群的性质。虽然目前还无法根据这些动物群对我国陆生哺乳动物年代的时限进行精确界定, 但依某些动物阶元(主要为科和属一级)的最早迁入或在该区的最早出现,以及在该区地层中的最后出席,概述了内蒙古中部地区新近纪动物群所指示的哺乳动物年代特征,并分别把通古尔期和保德期细分为3个和4个非正规亚期。深入的研究,包括在这一地区发现新的化石层位和材料,不仅会为内蒙古中部地区生物年代的厘定提供更多的资料,而且有助于完善中国新近纪地质年代的内涵。     

黑龙江青冈地区晚更新世猛犸象-披毛犀动物群生存的环境背景

更新世晚期大型哺乳动物消亡一直是科学界关注的热点科学问题,其消亡的环境背景和影响机制仍没有形成一致观点。我国东北地区晚更新世地层中保存有丰富的猛犸象-披毛犀动物群(Mammuthus-Coelodonta Fauna)化石记录,是研究更新世晚期大型哺乳动物生存环境及消亡过程的理想区域。黑龙江省青冈地区出土有典型的晚更新世哺乳动物化石种类,如真猛犸象(Mammuthus primigenius)、披毛犀(Coelodonta antiquitatis)等。本文以青冈县英贤村化石出土剖面为研究对象,通过孢粉分析,重建猛犸象-披毛犀动物群的生存环境背景。青冈地区猛犸象-披毛犀动物群出土于湖沼相沉积中,研究发现其生存环境的主要植被成分是蒿属、菊科、禾本科、莎草科和云杉属,指示草甸草原为主,局地生长有针叶林的植被景观。欧亚大陆晚更新世高纬度地区广泛分布的猛犸象草原植被曾延伸到我国东北地区。     

An Upper Pliocene <Emphasis Type="Italic">Equisetum</Emphasis> (Equisetales) from the Atotonilco El Grande Formation in Central Mexico

The present work documents the occurrence of Equisetum in the Upper Pliocene deposits of Central Mexico, describing and comparing fossil taxa with modern specimens. All taxonomic characters suggest a close affinity to the modern species Equisetum myriochaetum Schldl. et Cham. This work, which records the first Upper Pliocene occurrence of Equisetum in Central Mexico, confirms the wide distribution of the genus in high latitudes and more humid climates.     

Digest: The contribution of historical climate events in shaping the modern latitudinal diversity gradient of ancient reptiles

It is recognized that biodiversity changes across the planet latitudinally; however, the timing of and reasons for diversity loss at higher latitudes are not well understood. Meseguer and Condamine investigate phylogenies and fossil evidence of reptilian species and determine that global warming and cooling events allowed asymmetric extinction and dispersion across latitudes, suggesting a hypothesis where climate profoundly shapes the latitudinal diversity gradient in certain taxa.     

Effect of global atmospheric carbon dioxide on glacial–interglacial vegetation change

Global vegetation changes at the time‐scale of the Earth's orbital variations (10⁴–10⁵ years) have been interpreted as a direct effect of consequential climatic changes, especially temperature. At mid‐ and high latitudes, the evidence from fossil data and general circulation models (GCMs) supporting this hypothesis is strong, but at low latitudes there is a major discrepancy. GCMs predict temperature changes that are less than those inferred from palaeoclimatic data, including the plant fossil record. However, changes in atmospheric CO₂ concentrations can account for a high proportion of the low‐latitude vegetation change hitherto attributed to temperature change, and may thus explain the discrepancy. The implications of this finding are considerable for understanding patterns of macroevolution and ecosystem development throughout the geological record.     

Permian polar forests: deciduousness and environmental variation

Forests are expected to expand into northern polar latitudes in the next century. However, the impact of forests at high latitudes on climate and terrestrial biogeochemical cycling is poorly understood because such forests cannot be studied in the modern. This study presents forestry and geochemical analyses of three in situ fossil forests from Late Permian strata of Antarctica, which grew at polar latitudes. Stem size measurements and stump spacing measurements indicate significant differences in forest density and canopy structure that are related to the local depositional setting. For forests closest to fluvial systems, tree density appears to decrease as the forests mature, which is the opposite trend of self‐thinning observed in modern forests. We speculate that a combination of tree mortality and high disturbance created low‐density mature forests without understory vegetation near Late Permian river systems. Stable carbon isotopes measured from permineralized wood in these forests demonstrate two important points: (i) recently developed techniques of high‐resolution carbon isotope studies of wood and mummified wood can be applied to permineralized wood, for which much of the original organic matter has been lost and (ii) that the fossil trees maintained a deciduous habit at polar latitudes during the Late Permian. The combination of paleobotanical, sedimentologic, and paleoforestry techniques provides an unrivaled examination of the function of polar forests in deep time; and the carbon isotope geochemistry supplements this work with subannual records of carbon fixation that allows for the quantitative analysis of deciduous versus evergreen habits and environmental parameters, for example, relative humidity.     

Relative effect of taphonomy on calcification temperature estimates from fossil planktonic foraminifera

This paper explores the effects of preservation and taphonomy on the ultrastructure of recent and fossil (Quaternary and Neogene) Globigerinoides using scanning electron microscopy and thin section petrography. We show preservation states from: pristine (plankton tow) specimens that are “glassy”, have a microcrystalline test structure, and bear sharply defined interpore ridges with delicate spines; through core top and fossil specimens that have gametogenic calcite veneers of euhedral or lumpy deposits covering the interpore ridges and spine bases; to fossil material with extensive dissolution of the test wall and diagenetic calcite formed during shallow burial (less than 300 m below the sea floor). The latter produce a “grainy” texture to the test. Although we cannot unravel the precise effects of ecology and taphonomy on calcification temperature at every site, we show that for well-preserved fossil material with gametogenic calcite, temperature estimates are typically 2-3 °C cooler than modern sea surface, and are similar to those recorded using the δ¹⁸O of core top material from tropical latitudes. In contrast, at tropical sites with poor fossil preservation, estimates of calcification temperature are significantly cooler, sometimes by more than 10 °C than expected from present observations.     

Response of vegetation to climatic changes of different duration in the late neogene

The late Neogene climate is characterized both by a general cooling at middle and high latitudes and by short-term temperature oscillations that developed into the ice ages. The effect of these climatic forcings on vegetation is known in only a few cases where the fossil record is sufficiently long, closely sampled and well dated. These records are important in testing models of vegetational change and in demonstrating that present vegetation is a product of past climatic variability on different temporal scales.     

Fossil Araceae from a Paleocene neotropical rainforest in Colombia

Both the fossil record and molecular data support a long evolutionary history for the Araceae. Although the family is diverse in tropical America today, most araceous fossils, however, have been recorded from middle and high latitudes. Here, we report fossil leaves of Araceae from the middle-late Paleocene of northern Colombia, and review fossil araceous pollen grains from the same interval. Two of the fossil leaf species are placed in the new fossil morphogenus Petrocardium Herrera, Jaramillo, Dilcher, Wing et Gomez-N gen. nov.; these fossils are very similar in leaf morphology to extant Anthurium; however, their relationship to the genus is still unresolved. A third fossil leaf type from Cerrejón is recognized as a species of the extant genus Montrichardia, the first fossil record for this genus. These fossils inhabited a coastal rainforest ～60-58 million years ago with broadly similar habitat preferences to modern Araceae.     

Cretaceous Promecognathinae (Goleoptera: Garabidae): a new genus, phylogenetic reconstruction and zoogeography

A fossil carabid (Coleoptera) belonging to the subfamily Promecognathinae is described from Cretaceous crater lake deposits at Orapa, Botswana. The specimen, which is the first ever fossil promecognathine, is placed in a new genus Palaeoxinidium. The fossil supports a Cretaceous age determination for the sediments, and it indicates that the Orapa crater was, at least in part, heavily vegetated at the time of deposition. Cladistic analysis of the fossil and extant Promecognathinae indicates that the fossil represents the sister group of the extant taxa and that the latter, in turn, comprise a pair of sister groups. It is, therefore, proposed that the Promecognathinae should be divided into two tribes: the Palaeoaxinidiini, represented by the fossil, and the Promecognathini, represented by the extant groups. The Promecognathini should be subdivided further into the subtribes Promecognathina and Axinidiina, represented by the American and African species, respectively. Three alternative zoogeographic hypotheses that explain the distributions of the fossil and extant promecognathines are discussed and tests for the hypotheses are proposed.     

Influence of environmental factors on the wood structure of living and fossil trees

The mechanism of wood development records in varying degree the effects of both external and internal factors that are operating at the time of development. As a result, fossil woods spanning the last 370 million years represent a unique palaeo-environmental data-store. Data concerning external factors that can be reclaimed consist of: presence or absence of growth rings; ring widths; relative proportions of earlywood and latewood and the nature of the transition between them; “false” and “frost” rings and evidence of damage by animals or fire; occurrence of reaction wood. These effects have to be seen against a background of the influences of the internal factors. The development of wood involves the action of plant growth regulators. The production of an entire season’s growth of wood depends on a supply of photosynthate, partly stored from the previous year, and the remainder directly from photosynthesis during the current one. In any population of trees of the same species there will be genetic variation which will lead to differences in the wood formed by the individual trees even if they have all grown in a largely similar environment. However the external factors exert a much greater influence than the internal ones. Our earliest fossil woods (Upper Devonian) show either seasonless growth patterns or, if weak rings are perceptible, then the increments are extensive. This is consistent with the palaeo-equatorial position of all recorded Devonian woods. In the Carboniferous a few sites (marginal in the tropical belt?) show subdued (weak) growth rings. By the time of the Gondwana glaciation strong rings are shown in high southern latitudes, but most surprisingly there are sizeable increments well inside the palaeoantarctic circle. This phenomenon persists into the Mesozoic where lack of growth rings shows consistency with positions within the palaeo-equatorial latitudes. However occurrence of Cretaceous high latitude wood growth demonstrates that given an adequate ambient temperature, forest growth was possible close to both poles. It is shown that this is consistent with the total energy flux known to occur now in high latitudes.     

关于以色列国的基巴拉和哈约尼姆两洞穴的微矿物的研究：对于考古纪录中灰烬沉积的认识

关于以色列国的基巴拉和哈约尼姆两洞穴的微矿物的研究：对于考古纪录中灰烬沉积的认识斯·韦纳斯·希格尔奥·巴·约瑟夫关键词火,灰烬,矿物,红外光谱学,成岩作用火的考古纪录对于认识早期人类的技术能力是十分有趣的。通过研究烧骨、炭屑、石器、以及高温对于烧过的...