Detailed conodont analysis on the Yangjuan-Chupiwa section, Xinmin, Panxian County, Guizhou Province, revealed a conodont sequence including four Anisian conodont zones, viz. Nicoraella germanica Zone, Nc. kockeli Zon...Detailed conodont analysis on the Yangjuan-Chupiwa section, Xinmin, Panxian County, Guizhou Province, revealed a conodont sequence including four Anisian conodont zones, viz. Nicoraella germanica Zone, Nc. kockeli Zone, Paragondolella bifurcata Zone and Neogondolella constricta Zone. These zones indicate that the upper Guanling Formation consists of strata from the Bithynian to the lllyrian of the Anisian. Appearance of Neogondolella constricta suggests that the Anisian/Ladinian boundary might be in the overlying Yangliujing Formation. The Panxian Fauna with well-preserved marine reptile and fish fossils is proved to belong to the lower part of the conodont Nc. kockeli Zone in the studied area. Thus, the age of the Panxian Fauna could be the early Pelsonian of the Anisian.展开更多
The Luoping Biota consists of abundant and well-preserved marine fishes, reptiles, invertebrates, and plants. It occurs in the Middle Triassic Guanling Formation in Daaozi Village of Luoping County, Yun-nan Province, ...The Luoping Biota consists of abundant and well-preserved marine fishes, reptiles, invertebrates, and plants. It occurs in the Middle Triassic Guanling Formation in Daaozi Village of Luoping County, Yun-nan Province, China. Based on conodonts, the Luoping Biota is determined to lie within the Nicoraella kockeli Zone, which is assigned to the Pelsonian substage of the Anisian.展开更多
The Middle Triassic Panxian fauna is a physical marker and representative record of the rapid recovery of the Triassic marine ecosystem following the Early Triassic stagnant stage after the end-Permian mass extinction...The Middle Triassic Panxian fauna is a physical marker and representative record of the rapid recovery of the Triassic marine ecosystem following the Early Triassic stagnant stage after the end-Permian mass extinction. Ten marine reptile taxa have been found from the 1.82-2.10 m-thick fossiliferous level in the Upper Member of the Guanling Formation, which can be subdivided into three marine reptile beds through the analysis on the stratigraphic distributions of fossil reptiles. The Lower Reptile Bed yields the sauropterygians Placodus inexpectatus Jiang et al., 2008 and Lariosaurus hongguoensis Jiang et al., 2006, the ichthyopterygians Xinminosaurus catactes Jiang et al., 2008 and Phalarodon cf. Phalarodon fraasi Merriam, 1910, associated with Mixosaurus panxianensis Jiang et al., 2006, representing a stage of predominance of durophagous taxa. In this bed, the large complete skeletons may reach up to 2.3 m in length, and lithofacies and chemostratigraphic analyses indicate a relatively deep carbonate platform with an oxic water environment near the bottom, as well as a rising sea level The Middle Reptile Bed yields the sauropterygian Nothosaurus yangjuanensis Jiang et al., 2006 and the archosaur Qianosuchus mixtus Li et al., 2006, associated with Mixosaurus panxianensis Jiang et al., 2006. The fossils in this bed are characterized by its pincering dentition and large overall body size, with the largest possibly exceeding 3 m in length. This bed might represent a time of deepest basin with relatively anoxic condition near the bottom. The Upper Reptile Bed yields the sauropterygians Wumengosaurus delicatomandibularis Jiang et al., 2008, Keichousaurus sp., the protorosaur Dinocephalosaurus orientalis Li, 2003, and the ichthyopterygian Mixosaurus panxianensis Jiang et al., 2006. In this bed, reptilian taxa characterized by suction feeding appeared, and most are less than 1 m long. This bed corresponds to a period of decreasing water depth.展开更多
Two complete specimens from the Pelsonian （Middle Anisian, Middle Triassic） of Luoping, Yunnan Province, South China are referred to a new actinopterygian genus, Luopingichthys gen. nov., and ascribed to the perleid...Two complete specimens from the Pelsonian （Middle Anisian, Middle Triassic） of Luoping, Yunnan Province, South China are referred to a new actinopterygian genus, Luopingichthys gen. nov., and ascribed to the perleidiform family Polzbergidae based especially on a typical synapomorphy of a peculiar premaxillary-maxillary complex, i.e., the fusion between premaxillary and maxillary along the antero-dorsal margin of the maxillary. The new taxon differs from other deep-bodied representatives of the family, Felberia and Stoppania, in its fusiform or deep fusiform body shape; sickle-shaped preopercular with short infraorbital process; lack of modified scales at the base of the anal fin; the short-based dorsal fin; scarcely ornamented scales; and thin anterior teeth. Based on a redescription of the holotype of the taxon Ctenognathichthys hattichi from the Middle Triassic （Ladinian） Prosanto Formation, Canton Graubiinden, eastern Switzerland, the only known specimen, which shows the same fusion between premaxillary and maxillary, the systematic position of the species is clarified and the taxon is proposed to be a further representative of the family Polzbergidae, and is transferred to the new genus.展开更多
盘县新民乡羊圈村及其邻区关岭组上段产出两种混鱼龙:Mixosaurus panxianensis Jiang et al.,2006和Phalarodon cf.P.fraasi Merriam,1910,含混鱼龙类化石层时代应为中三叠世安尼期Pelsonian亚期。"Mixosaurus yangjuanensis Liu a...盘县新民乡羊圈村及其邻区关岭组上段产出两种混鱼龙:Mixosaurus panxianensis Jiang et al.,2006和Phalarodon cf.P.fraasi Merriam,1910,含混鱼龙类化石层时代应为中三叠世安尼期Pelsonian亚期。"Mixosaurus yangjuanensis Liu and Yin,2008"命名所依据的正模标本无关键的头骨特征,选取的头后骨骼做鉴定特征对混鱼龙类种一级分类无意义,鉴定特征所依据的基本骨块存在鉴定错误;"Mixosaurus maotaiensis"的厘定应无效;盘县动物群中无Mixosaurus cornalianus出现。展开更多
It is well known that most of South China was in a vast expanse of ocean dur-ing Early-Aliddle Triassic, so the fossil plants are quite rare there. So far as thescope of the world is concerned, the Anisian plants are ...It is well known that most of South China was in a vast expanse of ocean dur-ing Early-Aliddle Triassic, so the fossil plants are quite rare there. So far as thescope of the world is concerned, the Anisian plants are also very scarce. Inrecent years, however, a flora represented by Pleuromeia and Annalepis has beenfound in the Badong Formation in the Yangzi Gorge area, China. It occurs withMiddle Triassic marine bivalves, such as Eumorphotis (Asoella) cf.subillyrica (Hsu),Myophoria (Costatoria) cf.goldfussi mansuyi Hsu, etc., and lies over the strata withAnisian ammonites Progonoceratites. This flora, therefore, should undoubtedly be ofthe Anisian in age. This discovery will be of important significance not only for展开更多
In this paper,we provide two new Triassic palaeomagnetic poles from Winterswijk,the Netherlands,in the stable interior of the Eurasian plate.They were respectively collected from the Anisian(~247–242 Ma)red marly lim...In this paper,we provide two new Triassic palaeomagnetic poles from Winterswijk,the Netherlands,in the stable interior of the Eurasian plate.They were respectively collected from the Anisian(~247–242 Ma)red marly limestones of the sedimentary transition of the Buntsandstein Formation to the dark grey limestones of the basal Muschelkalk Formation,and from the Rhaetian(~208–201 Ma)shallow marine claystones that unconformably overlie the Muschelkalk Formation.The magnetization is carried by hematite or magnetite in the Anisian limestones,and iron sulfides and magnetite in the Rhaetian sedimentary rocks,revealing for both a large normal polarity overprint with a recent(geocentric axial dipole field)direction at the present latitude of the locality.Alternating field and thermal demagnetization occasionally reveal a stable magnetization decaying towards the origin,interpreted as the Characteristic Remanent Magnetization.Where we find a pervasive(normal polarity)overprint,we can often still determine well-defined great-circle solutions.Our interpreted palaeomagnetic poles include the great-circle solutions.The Anisian magnetic pole has declination D±ΔDx=210.8±3.0°,inclination I±ΔIx=-26.7±4.9°,with a latitude,longitude of 45.0°,142.0°respectively,K=43.9,A95=2.9°,N=56.The Rhaetian magnetic pole has declination D±ΔDx=32.0±8.7°,inclination I±ΔIx=50.9±8.1°,with a latitude,longitude of 60.6°,123.9°respectively,K=19.3,A95=7.4°,N=21.The poles plot close to the predicted location of global apparent polar wander paths(GAPWa Ps)in Eurasian coordinates and are feasible for future apparent polar wander path construction.They confirm that the intracontinental,shallow-marine Germanic Basin,in which the Muschelkalk Formation was deposited,existed at a palaeolatitude of 14.1°[11.3,17.1]N,in a palaeo-environment reminding of the Persian Gulf today.In Rhaetian times,palaeolatitudes of 31.6°[24.8,39.8]N were reached,on its way to the modern latitude of 52°N.展开更多
The Olenekian-Anisian Boundary(OAB)interval is an important time in Earth history,reflecting the last phase of marine ecosystem recovery in the aftermath of the end-Permian mass extinction.Despite this,the Global Stra...The Olenekian-Anisian Boundary(OAB)interval is an important time in Earth history,reflecting the last phase of marine ecosystem recovery in the aftermath of the end-Permian mass extinction.Despite this,the Global Stratotype Section and Point(GSSP)for the base of the Anisian remains undefined.The first appearance of the conodont Chiosella timorensis has been proposed as a potential index for the boundary;however,the discovery of this conodont with ammonoids traditionally considered to be Spathian has generated doubts about its suitability.The taxonomy and relationships of early Anisian conodonts,including species of Chiosella,remain understudied,which leads to difficulties in correlation.New species of Neogondolella(N.gradinarui)and Magnigondolella(M.n.sp.D)have been recognized from the leading GSSP candidate section for the OAB at De?li Caira,and from an additional OAB section at Guandao.Furthermore,several species previously identified in Canada and the USA can be recognized from these sections,improving correlation between Tethys and North America.One of these species may serve as a suitable alternative proxy for the OAB;for instance,N.curva appears just below the first Anisian ammonoids in De?li Caira,and just above the first appearance of C.timorensis in both De?li Caira and Guandao.Continued work on sections other than the candidate sections,and on the taxonomy of species outside of those traditionally proposed as indices,is required.展开更多
基金This study was financially supported by grants from the"985"project of Peking University,National Natural Science Foundation of China(grant 40272005)the Major Basic Research Projects of China(grant G2000077700).
文摘Detailed conodont analysis on the Yangjuan-Chupiwa section, Xinmin, Panxian County, Guizhou Province, revealed a conodont sequence including four Anisian conodont zones, viz. Nicoraella germanica Zone, Nc. kockeli Zone, Paragondolella bifurcata Zone and Neogondolella constricta Zone. These zones indicate that the upper Guanling Formation consists of strata from the Bithynian to the lllyrian of the Anisian. Appearance of Neogondolella constricta suggests that the Anisian/Ladinian boundary might be in the overlying Yangliujing Formation. The Panxian Fauna with well-preserved marine reptile and fish fossils is proved to belong to the lower part of the conodont Nc. kockeli Zone in the studied area. Thus, the age of the Panxian Fauna could be the early Pelsonian of the Anisian.
基金Supported by China Geological Survey (Grant No. 1212010610211)National Natural Science Foundation of China (Grant Nos. 90714010, 40872003, 40621002)State Key Laboratory of the Ministry of Science and Technology of China and State MOST Special Fund from the Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences
文摘The Luoping Biota consists of abundant and well-preserved marine fishes, reptiles, invertebrates, and plants. It occurs in the Middle Triassic Guanling Formation in Daaozi Village of Luoping County, Yun-nan Province, China. Based on conodonts, the Luoping Biota is determined to lie within the Nicoraella kockeli Zone, which is assigned to the Pelsonian substage of the Anisian.
基金supported bygrants from the National Natural Science Foundation ofChina(no.:40672002 and 40302009)the Program for NewCentury Excellent Talents in University(no.:NCET-07-0015)+1 种基金the Committee for Research and Exploration ofthe National Geographic Society of USA(no.:7886-05)Peking University,and was a contribution to the IGCP-572 project
文摘The Middle Triassic Panxian fauna is a physical marker and representative record of the rapid recovery of the Triassic marine ecosystem following the Early Triassic stagnant stage after the end-Permian mass extinction. Ten marine reptile taxa have been found from the 1.82-2.10 m-thick fossiliferous level in the Upper Member of the Guanling Formation, which can be subdivided into three marine reptile beds through the analysis on the stratigraphic distributions of fossil reptiles. The Lower Reptile Bed yields the sauropterygians Placodus inexpectatus Jiang et al., 2008 and Lariosaurus hongguoensis Jiang et al., 2006, the ichthyopterygians Xinminosaurus catactes Jiang et al., 2008 and Phalarodon cf. Phalarodon fraasi Merriam, 1910, associated with Mixosaurus panxianensis Jiang et al., 2006, representing a stage of predominance of durophagous taxa. In this bed, the large complete skeletons may reach up to 2.3 m in length, and lithofacies and chemostratigraphic analyses indicate a relatively deep carbonate platform with an oxic water environment near the bottom, as well as a rising sea level The Middle Reptile Bed yields the sauropterygian Nothosaurus yangjuanensis Jiang et al., 2006 and the archosaur Qianosuchus mixtus Li et al., 2006, associated with Mixosaurus panxianensis Jiang et al., 2006. The fossils in this bed are characterized by its pincering dentition and large overall body size, with the largest possibly exceeding 3 m in length. This bed might represent a time of deepest basin with relatively anoxic condition near the bottom. The Upper Reptile Bed yields the sauropterygians Wumengosaurus delicatomandibularis Jiang et al., 2008, Keichousaurus sp., the protorosaur Dinocephalosaurus orientalis Li, 2003, and the ichthyopterygian Mixosaurus panxianensis Jiang et al., 2006. In this bed, reptilian taxa characterized by suction feeding appeared, and most are less than 1 m long. This bed corresponds to a period of decreasing water depth.
基金supported by Peking University and NSFC(grant 40702001)by a grant from UNIMI Chancellorand FIRST funds for the Italian team
文摘Two complete specimens from the Pelsonian （Middle Anisian, Middle Triassic） of Luoping, Yunnan Province, South China are referred to a new actinopterygian genus, Luopingichthys gen. nov., and ascribed to the perleidiform family Polzbergidae based especially on a typical synapomorphy of a peculiar premaxillary-maxillary complex, i.e., the fusion between premaxillary and maxillary along the antero-dorsal margin of the maxillary. The new taxon differs from other deep-bodied representatives of the family, Felberia and Stoppania, in its fusiform or deep fusiform body shape; sickle-shaped preopercular with short infraorbital process; lack of modified scales at the base of the anal fin; the short-based dorsal fin; scarcely ornamented scales; and thin anterior teeth. Based on a redescription of the holotype of the taxon Ctenognathichthys hattichi from the Middle Triassic （Ladinian） Prosanto Formation, Canton Graubiinden, eastern Switzerland, the only known specimen, which shows the same fusion between premaxillary and maxillary, the systematic position of the species is clarified and the taxon is proposed to be a further representative of the family Polzbergidae, and is transferred to the new genus.
基金supported bythe grants from the National Natural Science Foundation of China(#40872019) to SQHfromthe Major Basic Research Projects(#2006CB806400) of the Ministry of Science and Technologyof China to SQH,WXC and LC+2 种基金from the Canadian Museum of Nature(R34) to WXCfrom the National Natural Science Foundation(#40772015,40121202) of ChinatheCAS/SAFEA International Partnership Program for Creative Research Teams to LC and WXC~~
文摘盘县新民乡羊圈村及其邻区关岭组上段产出两种混鱼龙:Mixosaurus panxianensis Jiang et al.,2006和Phalarodon cf.P.fraasi Merriam,1910,含混鱼龙类化石层时代应为中三叠世安尼期Pelsonian亚期。"Mixosaurus yangjuanensis Liu and Yin,2008"命名所依据的正模标本无关键的头骨特征,选取的头后骨骼做鉴定特征对混鱼龙类种一级分类无意义,鉴定特征所依据的基本骨块存在鉴定错误;"Mixosaurus maotaiensis"的厘定应无效;盘县动物群中无Mixosaurus cornalianus出现。
文摘It is well known that most of South China was in a vast expanse of ocean dur-ing Early-Aliddle Triassic, so the fossil plants are quite rare there. So far as thescope of the world is concerned, the Anisian plants are also very scarce. Inrecent years, however, a flora represented by Pleuromeia and Annalepis has beenfound in the Badong Formation in the Yangzi Gorge area, China. It occurs withMiddle Triassic marine bivalves, such as Eumorphotis (Asoella) cf.subillyrica (Hsu),Myophoria (Costatoria) cf.goldfussi mansuyi Hsu, etc., and lies over the strata withAnisian ammonites Progonoceratites. This flora, therefore, should undoubtedly be ofthe Anisian in age. This discovery will be of important significance not only for
文摘根据一保存基本完整的骨架建立了始鳍龙类的一新属、种——纤细滇美龙(Dianmeisaurus gracilis gen.et sp.nov.)。标本采自云南省罗平县中三叠统关岭组Ⅱ段,为体态细长的小型物种。新属种与同产于该地区的利齿滇东龙(Diandongosaurus acutidentatus Shang et al.,2011)和丁氏滇肿龙(Dianopachysaurus dingi Liu et al.,2011a)身体各部位比例和个体大小接近,头骨均具有吻部两侧不收缩、眼眶显著大于上颞孔的特征。但新种眼眶间距要明显小于上颞孔间距,下颌关节与枕髁位于同一水平位置,锁骨前外侧缘的锁骨前突粗大而厚实,尺骨近端明显宽于远端,有比后两种更多的荐前椎(三属种荐前椎数分别为41、38、39枚)。此外,与滇东龙相对比,新种眶前区短于眶后区,前额骨和后额骨不相交。同时,新种下颌联合短,夹板骨参与下颌联合构成。新种前颌和下颌前部齿虽然也为獠齿(犬齿状齿),但未呈显著增大。头后骨骼对比,虽然新种和滇东龙均具有标志性的锁骨前外侧突,但后者的锁骨前外侧突尖细。与滇肿龙相对比,新种尾前部尾肋细长且未见明显加宽肿胀、仅具一个骨化的远侧腕骨、距骨为圆形且不具有近端凹入。去除数据不全的清镇龙、广西龙和三桥龙后的鳍龙类分支系统学分析表明,滇美龙与滇东龙互为姊妹群,同时它们与贵州龙、马家山龙和滇肿龙一起构成了一仅由在中国发现的属种组成的单系类群。这一单系类群与幻龙类的亲缘关系近于它们与欧洲肿肋龙类(Dactylosaurus,Anarosaurus,Serpianosaurus和Neusticosaurus)的亲缘关系。三种小型始鳍龙类的发现,指示云南罗平地区在三叠纪安尼期中晚期时鳍龙类是一类有较高分异度的海生爬行动物。
基金funded through NWO Vidi Grant 864.11.004and NWO Vici Grant 865.17.001
文摘In this paper,we provide two new Triassic palaeomagnetic poles from Winterswijk,the Netherlands,in the stable interior of the Eurasian plate.They were respectively collected from the Anisian(~247–242 Ma)red marly limestones of the sedimentary transition of the Buntsandstein Formation to the dark grey limestones of the basal Muschelkalk Formation,and from the Rhaetian(~208–201 Ma)shallow marine claystones that unconformably overlie the Muschelkalk Formation.The magnetization is carried by hematite or magnetite in the Anisian limestones,and iron sulfides and magnetite in the Rhaetian sedimentary rocks,revealing for both a large normal polarity overprint with a recent(geocentric axial dipole field)direction at the present latitude of the locality.Alternating field and thermal demagnetization occasionally reveal a stable magnetization decaying towards the origin,interpreted as the Characteristic Remanent Magnetization.Where we find a pervasive(normal polarity)overprint,we can often still determine well-defined great-circle solutions.Our interpreted palaeomagnetic poles include the great-circle solutions.The Anisian magnetic pole has declination D±ΔDx=210.8±3.0°,inclination I±ΔIx=-26.7±4.9°,with a latitude,longitude of 45.0°,142.0°respectively,K=43.9,A95=2.9°,N=56.The Rhaetian magnetic pole has declination D±ΔDx=32.0±8.7°,inclination I±ΔIx=50.9±8.1°,with a latitude,longitude of 60.6°,123.9°respectively,K=19.3,A95=7.4°,N=21.The poles plot close to the predicted location of global apparent polar wander paths(GAPWa Ps)in Eurasian coordinates and are feasible for future apparent polar wander path construction.They confirm that the intracontinental,shallow-marine Germanic Basin,in which the Muschelkalk Formation was deposited,existed at a palaeolatitude of 14.1°[11.3,17.1]N,in a palaeo-environment reminding of the Persian Gulf today.In Rhaetian times,palaeolatitudes of 31.6°[24.8,39.8]N were reached,on its way to the modern latitude of 52°N.
文摘The Olenekian-Anisian Boundary(OAB)interval is an important time in Earth history,reflecting the last phase of marine ecosystem recovery in the aftermath of the end-Permian mass extinction.Despite this,the Global Stratotype Section and Point(GSSP)for the base of the Anisian remains undefined.The first appearance of the conodont Chiosella timorensis has been proposed as a potential index for the boundary;however,the discovery of this conodont with ammonoids traditionally considered to be Spathian has generated doubts about its suitability.The taxonomy and relationships of early Anisian conodonts,including species of Chiosella,remain understudied,which leads to difficulties in correlation.New species of Neogondolella(N.gradinarui)and Magnigondolella(M.n.sp.D)have been recognized from the leading GSSP candidate section for the OAB at De?li Caira,and from an additional OAB section at Guandao.Furthermore,several species previously identified in Canada and the USA can be recognized from these sections,improving correlation between Tethys and North America.One of these species may serve as a suitable alternative proxy for the OAB;for instance,N.curva appears just below the first Anisian ammonoids in De?li Caira,and just above the first appearance of C.timorensis in both De?li Caira and Guandao.Continued work on sections other than the candidate sections,and on the taxonomy of species outside of those traditionally proposed as indices,is required.
