Latest Guadalupian brachiopods from the Guadalupian/Lopingian boundary GSSP section at Penglaitan in Laibin, Guangxi, South China and implications for the timing of the pre-Lopingian crisis

A brachiopod fauna comprising nine species in eight genera from three closely spaced stratigraphic horizons of the same stratigraphic section is described for the first time from the Laibin Limestone in the uppermost part of the Maokou Formation in the Guadalupian/Lopingian (G/L) GSSP section at Penglaitan, Guangxi Autonomous Region, South China. The brachiopod assemblages are bracketed between two conodont zones: Jinogondolella xuanhanensis Zone below and Jinogondolella granti Zone above and, therefore, they can be safely assigned to the latest Capitanian in age. However, all but one of the nine brachiopod species from the Laibin Limestone carry strong early Lopingian (Wuchiapingian) aspect. Thus, the discovery of this brachiopod fauna not only suggests that some Lopingian brachiopod species had already appeared in the late Guadalupian (Capitanian); more importantly, it has also highlighted the fact that both the previously noted pre-Lopingian life crisis (or end-Guadalupian or Middle Permian mass extinction) and Lopingian recovery/radiation actually occurred in late Capitanian times, sometime before the G/L chronostratigraphic boundary. So far, the Penglaitan GSSP section provides the highest-resolution disappearance patterns of different fossil groups around the G/L boundary.     

内蒙古达茂旗巴特敖包地区包尔汉图剖面牙形刺生物地层

内蒙古达茂旗(达尔罕茂明安联合旗)巴特敖包地区志留纪、泥盆纪碳酸岩相地层发育,本区珊瑚、腕足类、层孔虫等底栖大化石的研究工作已有一定基础。但志留纪、泥盆纪地层在时代确定和对比上还存在很多问题,必须用主导化石门类牙形刺加以解决。研究表明：包尔汉图剖面的顶部属泥盆系无疑,应归入阿鲁共组,而不是西别河组;巴特敖包地区的海侵,始于罗德洛统卢德福德阶(Ludfordian)早期。本剖面没有发现文洛克世和罗德洛世早期的海相沉积。本文描写了一个志留纪牙形刺新种：Ozarkodina uncrispa sp．nov．。     

Additional thylacocephalans (Arthropoda) from the Lower Triassic (upper Olenekian) Osawa Formation of the South Kitakami Belt,Northeast Japan

The Lower Triassic Osawa Formation in the South Kitakami Belt, Northeast Japan, consisting mostly of mudstone of shallow-marine environment, was deposited during the late Olenekian (ca. 250 Ma), and is an important unit through which to examine the biotic recovery process after the end-Permian mass extinction. The Osawa Formation is the only unit in Japan that yields thylacocephalans (Arthropoda). Three species belonging to three genera have been reported before: Ankitokazocaris bandoi, Kitakamicaris utatsuensis and Ostenocaris sp. In addition to the known species, some thylacocephalans, including one new genus and three new species, are described in the present paper: Ankitokazocaris tatensis n. sp., Concavicaris parva n. sp., Miyagicaris costata n. gen. n. sp. and Ostenocaris? sp. Although Thylacocephala have a rather long stratigraphic range (from Silurian to Cretaceous) and are known from a wide geographical region, there are only about thirty genera in this group. The Osawa thylacocephalan fauna comprises at least five genera, making it one of the most diverse in the world at the generic level. During the Triassic Period, the Thylacocephala diversified and spread widely throughout low-latitude regions.     

Oldest known Dicoelosia and Epitomyonia,deep water brachiopods from the Beiguoshan Formation (Middle Katian,Upper Ordovician), Shaanxi,north China

Abstract: A diverse brachiopod fauna from a relatively deep water carbonate facies of the Upper Ordovician Beiguoshan Formation (uppermost Caradoc – lower Ashgill, middle Katian) is characterized by small shells and contains the oldest known Dicoelosia and Epitomyonia, two diagnostic taxa of deep water brachiopod palaeocommunities during the Late Ordovician and Silurian. Three new species are recognized: Dicoelosia cordiformis sp. nov., Dicoelosia perbrevis sp. nov. and Epitomyonia fui sp. nov. These pioneer forms of the family Dicoelosiidae show a relatively high degree of morphological plasticity. The shells of Dicoelosia from the Beiguoshan Formation range from the typical slender‐lobed form with a concavoconvex profile to the strongly equibiconvex, fat‐lobed morphotype that was not known previously until the late Silurian. The Beiguoshan dicoelosiids point to an important attribute of the deep water brachiopods: small generalists with high morphological plasticity, which make them ideal candidates as progenitors for the evolution of shallow water brachiopod faunas in shelf and platform depositional environments.     

Evolution,palaeoecology, and palaeobiogeography of the Late Ordovician–Early Silurian brachiopod Epitomyonia

Epitomyonia is characterized by various types of dorsal ridges, which may be transverse, longitudinal, or highly convoluted and probably served as skeletal supports for lophophores of various complexity. Multivariate analyses suggest that the Epitomyonia-bearing brachiopod associations lived in relatively shallow-water environment in the Late Ordovician, and inhabited mainly deep-water environments in the early Wenlock. The temporal and spatial change in the faunal distribution may be explained by three alternative scenarios: (1) Epitomyonia followed the broad evolutionary trend of the Palaeozoic Evolutionary Fauna to shift from shallow- to deeper-water settings over time; (2) the dicoelosiid communities could not compete with the large-shelled pentameride communities in continental shelf settings during the Early Silurian; or (3) only the shallow-water Epitomyonia died out in the Late Ordovician mass extinction event, whereas some poorly known deep-water Late Ordovician forms survived into the Early Silurian. Epitomyonia paucitropida n. sp. from the lower Whittaker Formation (late Katian) of the Mackenzie Mountains, northwestern Canada, is reported as the first known Ordovician species of Epitomyonia from the palaeocontinent of Laurentia, characterized by a small shell with weak, transverse dorsal ridges that are most primitive for the genus.     

新疆中天山汗吉尕组Helenifore robustum放射虫动物群及其年代地层学意义

汗吉尕组是新疆中天山温泉小区中泥盆统的一个地层单元,为海相碎屑岩夹火山碎屑岩沉积。过去在灰岩团块和灰岩砾石中发现较为丰富的中泥盆世珊瑚和腕足类化石。这次,我们在该组上部地层硅质岩透镜体中首次发现晚泥盆世弗拉晚期的放射虫Helenifore robustum动物群。对于温泉地区该组地层的时代归属,我们认为:由于已发现的中泥盆世珊瑚、腕足类化石主要产于灰岩砾石或外来块体中,因此,这些化石的时代并不代表该组形成的时代;而产于硅质岩透镜体中的晚泥盆世弗拉晚期的放射虫化石很可能代表该组的年代。全文共描述放射虫5属11种,归属3目4科。     

Tremadoc (earliest Ordovician) brachiopods from Purmamarca and the Sierra de Mojotoro, Cordillera Oriental of northwestern Argentina

The Late Tremadoc storm-dominated shoreface to inner platform deposits exposed west of the Purmamarca village (Coquena Formation) contain a considerably more diverse brachiopod fauna than previously reported. Coquinite horizons from the lower heterolitic succession have yielded monospecific associations of Nanorthis purmamarcaensis nov. sp. (formerly assigned to N. christianiae KJERULF), which is also reported from the Late Tremadoc rocks of the Cerro San Bernardo area. The fine-grained Upper Member of the Coquena Formation contains a more diverse fauna composed by Nanorthis brachymyaria nov. sp., Astraborthis quebradensis nov. sp. and the new plectorthid genus Lipanorthis (type species L. andinus nov. sp.). A different species of Lipanorthis (L. santalaurae nov. sp.) from the Mid Tremadoc Floresta Formation of the Sierra de Mojotoro is also described.     

宁夏的(竹蜓)

宁夏的含(竹蜓)地层出露较好,剖面和柱状剖面有7处.含(竹蜓)地层自下而上为:下石炭统臭牛沟组、中卫组,上石炭统羊虎沟组,上石炭—下二叠统太原组.(竹蜓)动物群有15属68种及亚种,其中1新种.可建立(竹蜓)化石带 Eostaffella-Mediocris 带 (C_1), Profusulinella 带 (C_2~1) 及 Sphaeroschwagertna 带 (P_1~1),并与甘肃靖远及华北地台其它地区的(竹蜓)化石带对比.     

Lopingian (Late Permian) brachiopods around the Wuchiapingian-Changhsingian boundary at the Meishan Sections C and D, Changxing, South China

The strata below the defined Wuchiapingian-Changhsingian boundary GSSP are mostly covered and obscured by faulting at the Meishan Section D. Therefore, it is very difficult to collect fossils there. After an intensive excavation at Meishan Section C, a diverse fauna based on high-resolution biostratigraphy comprising brachiopods, ammonoids, conodonts, fusulinids and small foraminifers were found. Among these fossils, brachiopods are the most dominant. Eleven species of 10 genera based on more than 1300 specimens are identified. This brachiopod fauna is of late Wuchiapingian-Changhsingian of Lopingian (Late Permian) in age as well constrained by the associated ammonoid Pseudogastrioceras sp., Jinjiangoceras and Konglingites sp., the fusulinid Palaeofusulina and the conodont lineage from C. longicuspidata to C. wangi. In terms of the changes of brachiopod fauna composition around Wuchiapingian-Changhsingian boundary, it clearly indicates a continuous transgression from the upper part of the Lungtan Formation to the lower part of the Changhsing Formation. A new species, Neochonetes (Huangichonetes) meishanensis, is described and some other species are discussed based on the new collection from Meishan Sections C and D.     

Lower Devonian vertebrates, arthropods and brachiopods from northern Vietnam

Additional vertebrates and ostracods from the bituminous shale of the Khao Loc Formation at Tong Vai, Ha Giang Province, northern Vietnam, corroborate its correlation with the upper part of the Xishancun (Xiaxishancun) Formation and the lower part of the Xitun and Lianhuashan formations of South China, and its Middle to Late Lochkovian age. The variations in morphology and ornamentation of the galeaspid Polybranchiaspis liaojaoshanensis from Tong Vai are discussed and regarded as possibly size and growth-related. A new acanthothoracid placoderm with a very deep dorsal process is described from Tong Vai and the specific distinction between the antiarchs Minicrania lissa from Tong Vai and M. lirouyii from Yunnan is supported by additional characters. Petalichthyid placoderms are recorded from this locality for the first time, and the skull of a juvenile youngolepidid sarcopterygian is described. Eurypterid fragments and a phyllocarid crustacean are also recorded from the Khao Loc Formation. A new species of the chonetid brachiopod genus Tulynetes, endemic to northern Vietnam, is described from the Pragian Mia Le Formation at Cu Le, Bac Kan Province, a new locality which yields a large diversity of taxa with outstanding preservation.     

A low-diversity,silicified Hirnantia Fauna from Butuo,southwestern Sichuan,on the western margin of Yangtze Platform

The latest Ordovician Hirnantia Fauna is distributed worldwide including South China, but with very few records from the western margin of the Yangtze Platform. A silicified Hirnantia Fauna from the uppermost Tiezufeike Formation in the Laoga section, Butuo County, southwestern Sichuan, enriches the fauna’s record and warrants the recognition of the upper part of the Tiezufeike Formation as the Kuanyinchiao Bed. Etching bulk limestone samples from this level with acetic acid yielded 275 specimens of Dalmanella testudinaria, Plectothyrella crassicosta, and Hindella crassa. The population dynamics are analyzed for three successive populations in the section. Size-frequency histograms and survivorship curves indicate gradual improvement of the palaeoenvironments during the end of the Late Ordovician glaciation. The low-diversity brachiopod assemblages recognized in our study are assigned to the Dalmanella-Plectothyrella Community (DP Community) according to their dominant species. It is comparable with two other examples of DP communities, one from the neighboring Guizhou Province of Southwest China, and the other from the Baltica Region.     

An upper Kungurian/lower Guadalupian (Permian) brachiopod fauna from the South Qiangtang Block in Tibet and its palaeobiogeographical implications

A brachiopod fauna including 15 species belonging to 14 genera is described from a thin carbonate succession of the Lugu Formation at the Anmu section in the northern part of the South Qiangtang Block, which is about 15 km south to the Longmu Co-Shuanghu Suture. The brachiopod fauna is late Kungurian or early Guadalupian in age in terms of the presence of the brachiopod species Vediproductus punctatiformis, “Cryptospirifer” omeishanensis, and Paraplicatifera regularis. This is also generally consistent with the age indicated by the fusulines (e.g., Cancellina, Chusenella, Monodiexodina, Nankinella, Neofusulinella, Pseudofusulina, and Sphaerulina) from this formation at the nearby Mari and Duoma A (DMA) sections. Palaeobiogeographically, the brachiopod fauna exhibits a typical Cathaysian affinity and all the species are reported commonly from the equivalents in South China and Cimmerian blocks, which strongly suggest that the South Qiangtang Block had drifted to a position in the warm-water or temperate regime close to South China.     

Los géneros Praectenodonta, Praenucula y Notonucula (Palaeotaxodonta : Bivalvia) en el Siluro-Devónico de Bolivia

Taxonomy of 57 bivalves, internal and external molds is described in this paper, corresponding to three paleotaxodontids genera Praectenodonta, Praenucula and Notonucula. Samples were collected from nine sites, where stratigraphic columns were measured in Silurian to Devonian series from Altiplano, Cordillera Oriental and Interandean of Bolivia. For the first time in Bolivia, Praectenodonta and Notonucula have been identified. Four species have been described, three of them are new: Praectenodonta boliviensis n. sp., Praenucula quichua n. sp. and Notonucula altiplanica n. sp. Paleogeography of new species and genera is proposed.     

Middle–Late Ordovician brachiopods from Ningnan,southern Sichuan Province,Southwest China: Implications for macroevolution and palaeogeography

Middle to Late Ordovician brachiopods from the Huadan Formation (upper Darriwilian–Sandbian) of Ningnan County, southern Sichuan Province, are systematically documented here for the first time. The locality belongs to the western margin of the Upper Yangtze Platform, South China palaeoplate, and the brachiopod fauna includes one new genus and three new species as well as five other constituents: Hingganoleptaena sp., Acculina zhongliangziensis n. sp., Ningnanmena longisepta n. gen. n. sp., Kassinella (Trimurellina) minuta n. sp., Lepidorthis typicalis Wang, 1955, Protoskenidioides weixinensis Zhan and Jin, 2005, Porambonites transversus Xu, Rong and Liu, 1974, and Psilocamerella sp. Taxonomically it is a typical representative of a Middle to early Late Ordovician brachiopod fauna, and, together with some other evidence from other fossil groups like trilobites, conodonts, chitinozoans, a late Darriwilian–Sandbian age could be inferred for the horizon yielding this fauna. According to the richness of each constituent, this fauna is suggested to be called the Acculina-Ningnanmena fauna (ANF). Numerical palaeogeographical analysis shows that two broad palaeobiogeographic provinces could be recognized during this particular time interval, and, although the ANF is grouped into the South China cluster, it shares very little similarity with other representatives of that group except for two cosmopolitans. It further confirms that the Great Ordovician Biodiversification Event (GOBE), in other words the Ordovician radiation, was actually manifested by the strong localization of major marine organisms such as brachiopods, trilobites, graptolites, etc.     

Discovery of Anticostia uniformis from the Xiazhen Formation at Zhuzhai,South China and its stratigraphic implication

The Xiazhen Formation is an Upper Ordovician lithostratigraphic unit in the Jiangshan-Changshan-Yushan (JCY) area, which contains series of Late Ordovician reef successions. The reef successions of the Xiazhen Formation at Zhuzhai are critical for evaluation of the Late Ordovician marine diversity and palaeoecology. However, their age has long been uncertain and generally is regarded as of upper Katian, based on the occurrences of shelly fossils and correlation with the stratigraphic equivalent Changwu Formation. The newly discovered graptolite species Anticostia uniformis, in the Xiazhen Formation, together with the combined evidence of brachiopods and sedimentology, indicates an age range for the graptolite locality from the Dicellograptus complanatus Biozone to the Diceratograptus mirus Subzone of late Katian, but the graptolites do not rule out the possibility that it is Hirnantian.     

Early Cambrian organophosphatic brachiopods from the Xinji Formation,at Shuiyu section,Shanxi Province,North China

Abundant and diverse small shelly fossils have been reported from Cambrian Series 2 in North China, but the co-occurring brachiopods are still poorly known. Herein, we describe seven genera, five species and two undetermined species of organophosphatic brachiopods including one new genus and new species from the lower Cambrian Xinji Formation at Shuiyu section, located on the southern margin of North China Platform. The brachiopod assemblage comprises one mickwitziid (stem group brachiopoda), Paramickwitzia boreussinaensis n. gen. n. sp., a paterinide, Askepasma toddense Laurie, 1986, an acrotretoid, Eohadrotreta cf. zhenbaensis Li and Holmer, 2004, a botsfordiid, Schizopholis yorkensis (Holmer and Ushatinskaya in Gravestock et al., 2001) and three linguloids, Spinobolus sp., Eodicellomus cf. elkaniiformis Holmer and Ushatinskaya in Gravestock et al., 2001 and Eoobolus sp. This brachiopod assemblage suggests a late Age 3 to early Age 4 for the Xinji Formation and reveals a remarkably strong connection with coeval faunas from East Gondwana, particularly the Hawker Group in South Australia. The high degree of similarity (even at species level) further supports a close palaeogeographic position between the North China Platform and Australian East Gondwana during the early Cambrian as indicated by small shelly fossil data.     

The Pugnellidae, a new stromboidean family (Gastropoda) from the Upper Cretaceous

Members of the new family Pugnellidae have long been considered to represent the earliest members of the Strombidae but have more recently been included with the Aporrhaidae. We here propose them to represent a new family since their low-spired, bulgous shells are quite distinct from the usually slender and high-spired shell of the Aporrhaidae. Eleven species are described here belonging to six genera from which one genus and five species are new. The new genusBizarrus includes large, unornamentedGymnarus-like species, and new species are described asPugnellus klitzschi, Perustrombus africanus, Perustrombus indicus, Pugnellus?bartheli andPyktes popenoei. The here described Pugnellidae are from the Coniacian/ Santonian of Mungo River in Cameroon, the Santonian Umzamba Formation in the Eastern Cape Province of South Africa, the Campanian-Maastrichtian Ariyalur Group in Tamil Nadu, southern India, the Maastrichtian Quiriquina Formation of central Chile and the Maastrichtian Ammonite Hill Formation in the Western Desert of Egypt. Their radiation and possible phylogenetic relations to other Late Cretaceous stromboids are discussed. The origin of this family appears to lie in eastern Asia from where they spread through the Indopacific, Tethys and Atlantic Oceans during the Cenomanian-Santonian before they finally reached eastern North America in the Campanian.     

End-Permian mass extinction of calcareous algae and microproblematica from Liangfengya,South China

A new assemblage of calcareous algae and microproblematica is reported from the Changxing Formation at the Liangfengya section in Chongqing, South China. This assemblage comprises eighteen species of seven genera, including three genera of gymnocodiaceaens (Gymnocodium, Permocalculus, and Tauridium), three genera of dasycladaleans (Epimastopora, Macroporella, and Mizzia), and one genus of microproblematica (Pseudovermiporella). A new algal species, Tauridium elongatum nov. sp., is described. Quantitative analysis indicates that the last occurrences of 22% of the species (4 out of 18) fall into a 52 cm thick interval of the uppermost Changhsingian. No calcareous algae are found in the Permian-Triassic boundary (P-T boundary) beds and the overlying Feixianguan Formation. Four out of 10 species have a stratigraphic abundance greater than 10% and all vanished in the uppermost Changhsingian. An abrupt extinction for calcareous algae occurred in the Clarkina yini conodont Zone.     

Silurian craniide brachiopods from Gotland

Seven craniide brachiopod genera are described from the Silurian (Wenlock–Ludlow) of Gotland, including one new genus and five new species. The new genus and species Thulecrania septicostata is unique among Silurian craniides as it possesses solid spines. The new species Lepidocrania multilamellosa is the first Silurian record of this poorly known Permian genus. The problematic North American Propatella Grubbs, 1939 , was originally described as a gastropod, but the new species Propatella palmaria from Gotland shows that it is a craniide with sutured hollow spines of a type not previously recorded from Silurian craniides. The dorsal valves of the new species Valdiviathyris? bicornis are remarkably similar to those of the type species and represent the first possible Palaeozoic record of this poorly known extant craniide. This first systematic study of craniide brachiopods from the Silurian of Gotland shows that the diversity is relatively high as compared to other known Silurian craniide faunas, but a more thorough comparison is not possible due to the lack of data from most parts of the world. The new data from Gotland support the view that the craniides were not affected by the end‐Ordovician extinction.