宁夏早渐新世查干布拉格哺乳动物群

1974年9月,笔者和范贵忠同志与宁夏地质局区测队二分队地层组的同志们,在阿拉善左旗豪斯布尔都盆地查干布拉格地区的绿根扎大盖附近采集到一批将在本文中报道的早渐新世哺乳动物化石。本文所报道的谷氏大角雷兽(Embolotherium grangeri)以及徐余瑄(1966)报道的副新两栖犀(Paracadurcodon alashanensis)为1959年采集到的。     

南海北部琼东南盆地渐新世-上新世沟鞭藻指示的沉积环境北大核心CSCD

通过对南海北部琼东南盆地渐新世—上新世3个钻井剖面412个沟鞭藻样品的系统分析,发现了较丰富的沟鞭藻化石。根据沟鞭藻化石丰度、分异度变化以及特征性的环境指示种,对琼东南盆地渐新世至上新世的沉积环境进行了详细研究。认为研究区从早渐新世早期海水开始入侵,至早渐新世晚期海侵范围进一步扩大,一直持续到晚渐新世;早中新世沟鞭藻化石数量和种类明显出现低谷,发生了一次较为明显的海退;中中新世至晚中新世,沟鞭藻化石较丰富,丰度和分异度增加,海水明显比早中新世沉积时期加深;早上新世早期,指示海侵的化石属种较丰富,反映了温暖浅海的沉积环境;早上新世晚期,指示一种开阔的海洋环境,水体较深;晚上新世早期,沟鞭藻化石属种面貌反映了热带浅海环境,但水体可能比早上新世晚期沉积时要浅;晚上新世晚期,指示海侵的沟鞭藻化石属种达到最繁盛时期,海侵范围进一步扩大。     

南海北部琼东南盆地渐新世—上新世沟鞭藻指示的沉积环境

通过对南海北部琼东南盆地渐新世—上新世3个钻井剖面412个沟鞭藻样品的系统分析,发现了较丰富的沟鞭藻化石。根据沟鞭藻化石丰度、分异度变化以及特征性的环境指示种,对琼东南盆地渐新世至上新世的沉积环境进行了详细研究。认为研究区从早渐新世早期海水开始入侵,至早渐新世晚期海侵范围进一步扩大,一直持续到晚渐新世;早中新世沟鞭藻化石数量和种类明显出现低谷,发生了一次较为明显的海退;中中新世至晚中新世,沟鞭藻化石较丰富,丰度和分异度增加,海水明显比早中新世沉积时期加深;早上新世早期,指示海侵的化石属种较丰富,反映了温暖浅海的沉积环境;早上新世晚期,指示一种开阔的海洋环境,水体较深;晚上新世早期,沟鞭藻化石属种面貌反映了热带浅海环境,但水体可能比早上新世晚期沉积时要浅;晚上新世晚期,指示海侵的沟鞭藻化石属种达到最繁盛时期,海侵范围进一步扩大。     

宁夏海原两个第三纪中期哺乳动物群的发现

在宁夏南部海原地区首次发现了第三纪中期的哺乳动物化石。它们产自二个不同的层位：上层的采自红柳沟组的底部;下层的产自清水营组的上部,我们称为袁家窝窝动物群。袁家窝窝动物群的时代为中渐新世。这一动物群在海原的发现不但将产中渐新世哺乳动物群的地点往南推移,而且表明在海原的清水营组时代的上限为中渐新世。在红柳沟组底部发现的哺乳动物群表明其时代可能为早中新世（或更早）,显然要比典型地区的红柳沟组的时代－中中新世要早。这不但表明红柳沟组是异时性的,至少代表早－中中新世的沉积,而且说明在中新世时从早期到中、晚期宁夏盆地的沉积中心可能由南向北推移。这很可能与六盘山的抬升有关。     

内蒙古苏尼特左旗第三纪中期哺乳动物化石新地点

报道了内蒙古自治区苏尼特左旗白音宝力道乡嘎顺音阿得格地区一个第三纪中期哺乳动物化石新地点。对哺乳动物化石的初步研究表明,该区覆盖于晚古生代花岗岩基底上的第三纪沉积物时代可能为晚渐新世─早中新世的过渡层位,而不是过去认为的中中新世通古尔组。     

蒙古中部湖泊之谷沉积岩-玄武岩共存的渐新世地层:蒙古-奥地利合作项目回顾(英文)

Taatsiin Gol和Taatsiin Tsagaan Nuur地区的渐新世沉积序列具有重要的地层学意义:这里出露的三达河组和Loh组沉积含有多个化石层和玄武岩夹层。在蒙古-奥地利合作项目中,从研究区域的33个剖面/化石地点的85个化石层中采集了289种化石(11种腹足类、2种两栖类、9种爬行类和267种哺乳类)。本文提供了所有地点的完整哺乳动物清单,并结合大、小哺乳动物的新资料,对蒙古非正式的生物带A,B,C和C1进行了更新。40Ar/39Ar测年给出了至少两组玄武岩年龄:早渐新世玄武岩I组大约31.5Ma,晚渐新世玄武岩II组大约28Ma。它们可以用作渐新世哺乳动物地层学的年代校正点。从早渐新世至晚渐新世,哺乳动物群发生了显著的变化,包括晚渐新世种数的明显减少。这种趋势在肉齿类、食肉类和反刍类中最为突出。     

内蒙古中渐新世仓鼠化石的发现

本文记述了在内蒙古中渐新统中发现的仓鼠化石三属四种 Cricetops minor 新种, Cricetops dormitor, Eucricetodon caducus 和 Selenomys mimicus.这是中渐新世仓鼠化石在我国的首次发现.它肯定了三盛公地区产该化石的地层时代为中渐新世;进一步证明了 Selenomys 不是 aplodontid,而是 cricetid,应归入 Cricet■dae 科.     

内蒙古阿左旗乌兰塔塔尔地区渐新世地层剖面及动物群初步观察

内蒙古阿左旗乌兰塔塔尔地区的渐新世地层中,哺乳动物化石丰富,种类繁多。本文是这个动物群研究的初步报道,除对动物群中各成员和地层概况做了简单介绍外,还对化石层的时代作了初步探讨。     

蒙古新发现的渐新世山河狸和松鼠类化石(英文)

蒙古中部地区的三达河组(HsandaGolFormation)是亚洲渐新世陆相地层的经典地层之一。三达河组的沉积岩层现被分成两个岩性段:上部早渐新世晚期-?晚渐新世山地段(ShandMember)和下部早渐新世早期塔塔尔段(TatalMember);两岩段间有时夹有KharKhoroo玄武岩层(BryantandMcKenna,1995;MengandMcKenna,1998)。该玄武岩层的时代用40Ar/39Ar法被确定为距今31.5Ma(Hcketal.,1999,他们称其为BasaltI)。三达河组中产有丰富的哺乳动物化石,特别是啮齿类化石(MatthewandGranger,1923;Kowalski,1974;RussellandZhai,1987;Hcketal.,1999)。近年来,本文的后一作者在三达河组中又采集到一批啮齿类化石,其中包括松鼠和山河狸2科的化石。本文是对这两类化石新材料的记述。现生的松鼠科分异很大,而且大多数都分布在亚洲。然而,松鼠科化石在古近纪时在北美和欧洲却很丰富。在北美出现于晚始新世,在渐新世时已明显分异;在欧洲出现于早渐新世,在中新世时分异很大。相反,亚洲古近纪的松鼠化石却发现得很少,标本也很破碎。已报道的只有3件标本。2件产自党河下游地区:Bohlin(1946)报道的晚渐新世的Sciurussp.,标本只是2枚单个臼齿(M3和m2);王伴月、邱占祥(2004)报道的早渐新世的党河鲜松鼠(Oligosciurusdangheensis),标本只是一段带m1～2的下颌骨。还有一件是Minjin(2004)报道的蒙古渐新世的三达河克热姆鼠(Kheremhsandgoliensis),标本也只是一段带m1～3的下颌骨。本文报道的松鼠化石产自蒙古国的巴彦洪戈尔省的塔石盖贝(TashgainBel)地点的三达河组上部山地段,时代为早渐新世晚期-?晚渐新世。这批松鼠化石标本包括1件具P3～M3的上颌骨(PC369)和2段下颌骨(PC3610和PC3611)。这是亚洲古近纪目前已知的最好的一批松鼠化石标本,代表松鼠科Kherem属的一新种:亚洲克热姆鼠(Kheremasiaticasp.nov.)。其主要特征是颊齿较大,较宽;下内尖的高度和下次尖的大小从m1到m3变化不大,彼此相近;下内脊较明显;下内尖较明显,与下后边脊间有浅沟分开等。K.asiatica的形态特征表明,Kherem属应归入北美的Cedromurinae亚科。新的发现表明,亚洲渐新世的松鼠已发生了分异,至少可分为3支。以Kherem为代表的一支,与北美早期的cedromurines有较近的系统关系。它可能是由类似于北美Oligospermophilus的种类演化并迁徙到亚洲来的。现生的山河狸只有一种(Aplodontiarufa),仅生活在北美西部沿海地区。但从始新世到中新世,山河狸却遍布全北区。它们在北美较繁盛,分异大,但在亚洲发现得很少。在亚洲渐新世地层中虽曾报道过3属4种山河狸化石,但材料都很少(Prosciurusordosicus和P.?shantungensis均只有一枚单个的牙)。山河狸化石在蒙古渐新世地层的新发现表明,亚洲渐新世的山河狸化石比已知的要丰富。本文描述的山河狸化石分别采自蒙古南戈壁省Shunkt地点的山地段和前杭爱省UlaanKhongil(=TatalGol)地点的塔塔尔段。它们代表原松鼠属的3类:蒙古原松鼠(新种)(Prosciurusmongoliensissp.nov.)、蒙古原松鼠(相似种)(P.cf.P.mongoliensis)和小原松鼠(新种)(P.pisinnussp.nov.)。蒙古原松鼠的主要特征是下颊齿的下中附尖与下后附尖脊连,下中尖发育较弱,下外中脊弱或无;p4无下前边尖和下前齿带;m1具从下外脊伸向下次脊的小刺;m2和m3的下后脊II较发育;下次脊在p4和m1后弯,与下后边脊连,在m2和m3横向,伸达下外脊等。蒙古原松鼠(相似种)与蒙古原松鼠的区别是:颊齿尺寸较小,p4具明显的下外中脊,p4和m1的下次脊弯曲度较缓,m1缺从下外脊伸向下次脊的小刺,m2～3的下后脊II较短等。小原松鼠的主要特征是:个体较小;齿冠较低;下臼齿的下中附尖孤立;下颊齿的下次脊横向、较低,与下外脊连,下中尖和下外中脊均较明显,下次尖明显向前颊侧延伸,具明显的齿带等。蒙古渐新世啮齿类化石的新发现表明,亚洲渐新世的松鼠和山河狸与北美的关系要比与欧洲的近。     

珠江口盆地荔湾凹陷W22井渐新世生物地层研究

通过对珠江口盆地荔湾凹陷超深水井W22井3 266～3 991 m井段72个样品开展有孔虫和钙质超微化石分析,讨论了该层段的地层划分并确定了其年代。研究层位含有丰富的有孔虫和钙质超微化石,详细的生物地层学分析显示其属于渐新世。其中,有孔虫分析发现3 390 m以下为早渐新世P18-P21a带沉积、3 380 m以上为晚渐新世P21b-P22带至N4带下部沉积,显示其地层年代为33-23 Ma;而钙质超微化石分析则揭示出该层位包含了自NP25带底部到NP21带的地层,下渐新统/上渐新统的沉积界限在3 390 m左右, Coccolithus formosus的末现面出现在3 841 m表明钻井3 841 m以深地层年代大于32.92 Ma,但更深地层未发现始新世钙质超微化石,表明底部年龄仍为早渐新世,但推测已经接近渐新世/始新世界限(33.89 Ma)。荔湾凹陷渐新世经历了从陆架浅海到上陆坡半深海环境的演变。     

河南卢氏盆地的中兽化石

记述了河南卢氏盆地的中兽科化石材料,命名了强中兽属一新种———李氏强中兽(Harpagolestesleeisp.nov.)。该种P4后附尖非常发育、向颊侧突出;M2的原尖长,前端偏于舌侧、后端偏于颊侧,冠面轮廓近于长方形。报道了东方强中兽(Harpagolestesorientalis)的第一件下颌标本,并对该种的特征进行了补充和修订。描述的一个厚中兽未定种(Pachyaenasp.)可能是该属已知最晚的代表。还鉴定出两件Mongolestes属的标本及一件属种未定的中兽科化石。     

Oligocene palynoflora in the northern part of South China sea

In the northern part of South China Sea, including Tonkin Gulf, Hainan Island, Leizhou Peninsula and some basins of Guangdong Province, Oligocene deposits are composed of motley, mainly grey, greyish green and dark red clay and sandstone, containing very rich pollen and spores. Most of them are of the components which exsisted in Tertiary, particularly in Oligocene deposits of Northern America and Eurasia, such as Gothanipollis paichanensis Ke & Shi, Ulmus granopollenites Rouse, Symplocos scabropollinia Traverse, Engelhardtia spackmaniana Traverse, etc. At the same time some important Oligocene and Early Miocene pollen types of Borneo are found there, such as Crassoretitriletes vanraadshooveni Germeraad & al., Florschuetzia semilobata Germeraad & al., F. trilobata Germeraad & al., Magnastriatites howardi Germeraad & al., Jandufouria seamrogiformis Germeraad & al., Verrucatosporites usmansis (Hammen) Germeraad & al., Margocolporites vanwijhci Germeraad & al., Psilatricolporites operculatus Hammen & Wymstra, Monoporites annulatus Hammen and Zonocostites sp., etc. On the other hand in Oligocene palynoflora of Borneo there appear pollen types assigned to temperate plants or mountain plants of northern hemispherae (Pinus, Picea, Tsuga, Ephedra and Alnus), which are found in abundence in Oligocene palynoflara of the investigated area particularly in Late Oligocene. All of this indicats that the palynoflora of the Northern part of South China Sea was closely related with that of Borneo in Oligocene. This similarity of palynofloras in the two localities may be due to the geographycal proximity of Borneo to the main land of Asia. In paleoecological aspect, we have found there is plenty of pollen and spores of land and fresh water plants, while those reflecting marine and coastal enviroments (Rhizophora and Sonneratia) are rather scanty. This shows that in Oligocene period the investigated area was a land. Tonkin Gulf along with Hainan Island and Leizhou Peninsula formed an inland depression at that time. Abundant pollen of mountain plants and temperate plants indicats, that there weremountains in or around the area of interest.     

甘肃党河下游地区早渐新世哺乳动物化石的发现

描述了产于党河下游地区的狍牛泉组下部地层中的叮当沟哺乳动物群。化石共计 1 1属 1 4种 :Palaeoscaptorcf.P .acridens、Palaeoscaptorsp .、Oligosciurusdangheensisgen .etsp .nov.、Tataromyscf.T .sigmodon、Karakoromysdecessus、Coelodontomysasiaticus、Parasminthusspp .、Cricetidaegen .etsp .indet.、Desmatolagusgobiensis、D .pusillus、Allaceropssp .、Schizotheriumordo sium和Parabrachyodussp .。党河鲜松鼠 (新属、新种 )的主要特征是个体较小而原始 ,下颌骨咬肌窝前缘达m2下方 ;冠状突前缘近于垂直 ,起于m2后部下方 ,颊齿齿冠很低 ,臼齿具明显的下内尖、下次脊和下中附尖 ,但无下中尖。上述化石的已知时代分布表明 ,狍牛泉组下部的叮当沟哺乳动物群的时代为早渐新世     

Evolution and extinction of Afro-Arabian primates near the Eocene-Oligocene boundary

Revised age estimates for the primate-bearing localities of the Jebel Qatrani Formation (Fayum area, northern Egypt) have provided a new perspective on primate response to early Oligocene climate change in North Africa. Environmental changes associated with early Oligocene cooling might have driven the local extinction of at least 4 strepsirrhine primate clades (adapids, djebelemurines, plesiopithecids and galagids). Contrary to previous suggestions, oligopithecid (and possibly proteopithecid) anthropoids persisted beyond the Eocene-Oligocene boundary (EOB) in the Fayum area, and the former group evidently continued to diversify through the early Oligocene at lower latitudes. Propliopithecids and parapithecine parapithecids first appear in the Jebel Qatrani Formation millions of years after the EOB, so their derived dental and gnathic features can no longer be interpreted as sudden adaptive morphological responses to earliest Oligocene climatic events. Evidence for latitudinal contraction of Afro-Arabian primate distribution through the early Oligocene suggests that the profound late Oligocene restructuring of Afro-Arabian primate communities is most likely to have occurred in equatorial and low-latitude tropical Africa.     

The late Eocene hyracodontid perissodactyl Ardynia from Saint Jacques,Inner Mongolia,China and its implications for the potential Eocene–Oligocene boundary

Saint Jacques is a classic Oligocene fossil locality in China, which was first investigated by P. Teilhard de Chardin and E. Licent in 1923. All the fossil mammals previously reported from the area are Oligocene in age. Here we report some new material of the hyracodontid Ardynia from two lower horizons in the Saint Jacques area. These new specimens represent two species: Ardynia praecoxMatthew and Granger, 1923 and A. ordosensis n. sp. A right lower jaw of Ardynia praecox with complete i1-c shows that i2 is the largest. The new species, Ardynia ordosensis, is characterized by a moderately hypsodont M1 with a pillar-like “crista” and the metaloph connecting the ectoloph distal to the metacone, characters that are more similar to those of A. altidentata than to any other species in Ardynia. The stratum bearing Ergilian Ardynia extends the deposits at Saint Jacques down to the upper Eocene. In combination with early Oligocene microfossils from the strata overlying the upper Eocene Ardynia-bearing layers, it is reasonable to conclude that the Saint Jacques section may bracket, or likely document, the Eocene–Oligocene transition.     

DISCOVERY OF TWO MID-TERTIARY MAMMALIAN FAUNAS FROM HAIYUAN, NINGXIA, CHINA

Inl988-199otheRegionalGeologicalSurveyTeamoftheGeologicalBureauofNingxia(RGSN)foundsomefossilmammalsinthelowerpartoftheHo11g1iugouFormationandtheupperpartoftheOligocene.Inl992ajointteamoflnstituteofVertebratePaleontologyandPaleoanthropo1ogy,AcademiaSinica(IVPP),andtheRGSNwenttoHaiyuailCountyandcollectedmorefossilmamma1sfromtheYuanjia-wowoareausi11gascreen-washingmethodThemammalfaunafromthelowerpartoftheHongliugouFormationiscomposedofAprotodonsp.,Indricotheriidaeindet.,Rhinoceroti…     

Evolutionary trend of Zoophycos morphotypes from the Upper Cretaceous–Lower Miocene in the type pelagic sections of Gubbio,Italy

About 200 Zoophycos specimens, including 90 specimens studied in detail, have been analysed in the continuous Upper Cretaceous–Lower Miocene pelagic sedimentary type sections of the Gubbio area (the Contessa Highway, Contessa Quarry and Bottaccione sections, Northern Apennines). The sediments are reddish to grey limestones and marls of the Scaglia Group and marls with volcaniclastic deposits of the Bisciaro Formation. The aim was to examine the evolutionary trend of what is probably the most debated trace fossil of all time, from the Upper Cretaceous to Lower Miocene. Despite having been found in beds ranging from the Cambrian to the present, no consensus has been reached regarding mode of construction, tracemaker or ethological explanation for Zoophycos. Four Zoophycos morphotypes are recognized at Gubbio showing variations of major and minor lamellae, apex, lobes and whorls: the Cretaceous–Eocene cone‐shaped type 1, the Upper Eocene–Middle Oligocene helicoidal type 2, the Oligocene lobate type 3 and the Upper Oligocene–Lower Miocene flat type 4. The very high ichnodensity in some beds (hundreds of specimens in discrete levels of the Bisciaro Formation, now destroyed by quarrying) seems to find explanation in abnormal concentrations of phytodetritus and organic matter on the seafloor in some periods. This very high abundance in discrete levels reflects a change in sedimentation and seafloor conditions at pre‐flysch deposition. Due to such high ichnodensity, many adjacent specimens display deformed outer margins. Taphonomic analysis shows a variation of whorls, laminae and U‐shaped lobes, reflecting ontogenetic development of the tracemaker(s) (?sipunculid worms).     

中国禾本科植物上的柄锈菌属一新种和一新记录(英文)

报道了中国禾本科植物上柄锈菌属1新种和1新记录变种。圆柱披碱草Elymus cylindricus和披碱草E.dahuricus上的阿拉善柄锈菌Puccinia alxaensis为新种;野青茅Deyeuxia pyramidalis上的矮柄锈菌砂禾变种Puccinia pygmaea var.ammophilina为中国新记录。提供了详细的形态描述和线条图。研究标本保存在赤峰学院菌物标本室(CFSZ)和中国科学院菌物标本馆(HMAS)。     

Remarques sur la stratigraphie des terrains tertiaires des bassins de Narbonne-Sigean et de Leucate (aude) a l'aide des micromammiferes

The discovery of rodents in the lacustrine and brackish deposits of the Narbonne-Leucate area classicaly dated as Oligocene, indicate that they are Oligocene and lower Miocene (Aquitanian) in the Narbonne-Sigean basin, and that the marls and limestones of the Leucate plateau and cliff are Pliocene.     

Oxygen isotope ranking of late Eocene and Oligocene planktonic foraminifers: Implications for Oligocene sea-surface temperatures and global ice-volume

Oxygen isotope analyses of late Eocene and Oligocene planktonic foraminifers from low and middle latitude sites in the Atlantic Basin show that different species from the same samples can yield significantly different isotopic values. The range of isotopic values observed between species is greatest at low-latitudes and declines poleward. Many planktonic foraminifers exhibit a systematic isotopic ranking with respect to each other and can therefore be grouped on the basis of their isotopic ranking. The isotopic ranking of some taxa, however, appears to vary geographically and/or through time.Isotopic and paleontologic data from DSDP Site 522 indicate that commonly used isotopic temperature scales underestimate Oligocene sea surface temperatures. We suggest these temperature scales require revision to reflect the presence of Oligocene glaciation. Comparison of isotopic and paleontologic data from Sites 522, 511 and 277 suggests cold, low-salinity surface waters were present in high southern latitudes during the early Oligocene. Lowsalinity, high latitude surface waters could be caused by Eocene/Oligocene paleogeography or by the production of warm saline bottom water.