New Middle Devonian conodont data from the Dong Van area,NE Vietnam (South China Terrane)

Middle Devonian conodonts from the Si Phai section in NE Vietnam are described. The section ranges from the Middle Devonian ensensis to timorensis conodont zones to the Late Devonian rhomboidea conodont Zone. A rich overall assemblage is described, including 27 taxa of species or subspecies rank and 11 taxa described in an open nomenclature. Among the dominant Polygnathus forms, four new taxa are described: Polygnathus linguiformis saharicus subsp. nov., Polygnathus linguiformis vietnamicus subsp. nov., Polygnathus rhenanus siphai subsp. nov., and Polygnathus xylus bacbo subsp. nov. Conodont assemblages are attributed to polygnathid, polygnathid-klapperinid, and klapperinid conodont biofacies representing hemipelagic to pelagic environments. The klapperinid biofacies, unreported in the previous literature, are here attributed to offshore areas of the external shelf. The taxonomic compositions of the studied conodont assemblages, as well as their CAI characteristics (CAI 4–5), suggest a palaeogeographic affinity of the studied strata to the Chinese Devonian Guangxi Basin, and the South China Terrane in general. Furthermore, the conodont biofacies and the palaeogeographic distribution of the fauna are discussed.     

Conodont biostratigraphy of Upper Devonian–Lower Carboniferous deposits in eastern Alborz (Mighan section), North Iran

The Devonian/Carboniferous (D/C) transition is characterized by a major transgressive/regressive cycle which led to a widespread ocean anoxia known as the Hangenberg Black Shale Event (HBSE), as well to a major sea-level fall (Hangenberg Sandstone Event, HSSE), recognized around the world. Both events are known as the Hangenberg Crisis. In order to examine the D/C transition in shallow water environment, the Mighan section in eastern Alborz was studied in terms of conodont biostratigraphy and stable isotope geochemistry. Twenty-five conodont species belonging to seven genera were identified and 5 conodont zones discriminated; namely, the Bispathodus aculeatus aculeatus Zone, Bispathodus costatus Zone, Bispathodus ultimus Zone, Siphonodella praesulcata Zone, costatus-kockeli Interregnum, and the sulcata Zone. Below the Devonian–Carboniferous boundary (DCB), the Hangenberg Black Shale and Hangenberg Sandstone equivalents were recognized, representing the Hangenberg Crisis that highly affected trilobite, ammonoid, brachiopod and conodont faunas at Mighan and worldwide. The kockeli Zone of the latest Famennian is missing at Mighan due to the lack of conodonts, probably related with the major environmental changes linked with the Hangenberg Crisis recognizable worldwide. Carbon isotopes measured of micrites from Mighan indicate a proximal depositional environment of a shallow shelf with terrestrial input and the oxygen isotope values from conodont apatite suggest warm seawater temperatures of tropical and subtropical setting in the study area.     

Erster Nachweis der Agoniatitidae (Ceph.) im Unterdevon von Nevada (USA)

From the Lower Devonian of Nevada (USA) a newly discovered ammonoid,Mimagonia- titesi n. sp., aff.M. angulostriatus Bogoslovski 1969, is described. The specimen was found in strata belonging to the highserotinus Zone of the conodont chronology resp. the lowerholynensis Zone according to the tentaculite zonation (late Dalejan resp. Upper Emsian). Suture line and umbilicus are not preserved; therefore the systematic position is not fully verified. But the fragmentary shell provides strong indications toMimagoniatites Eichenberg, a genus up till now unknown from the central Cordilleran Province.     

New insights into the base of the Emsian (Lower Devonian) in South China

Traditionally, the lower boundary of the Emsian (Lower Devonian) has been defined as the base of the dehiscens Zone marked by the first entry of the conodont Polygnathus dehiscens. However, following taxonomic revision of P. dehiscens, the current practice is to use the first appearance of P. kitabicus to define the base of the Emsian. As a result, specimens previously identified as P. dehiscens from South China need to be thoroughly reviewed. Careful examination of the oral and aboral features of the platform reveal that most specimens previously described as P. dehiscens from nine sections in Guangxi and Yunnan actually refer to P. excavatus excavatus or P. excavatus ssp. 114. In the South China Block, widespread and massive deposition of Devonian carbonates began during the time of the excavatus Zone, whereas the kitabicus Zone is probably located in the underlying strata, which mainly comprise marine siliciclastic rocks. Thus, the precise level of the lower boundary of the Emsian in South China is still unknown.     

Famennian conodonts from the Hongguleleng Formation at the Bulongguoer stratotype section,western Junggar,Northwest China

The Hongguleleng Formation, the highest and most important Devonian marine carbonate horizon in western Junggar, contains an endemic shallow-water Icriodus–Polygnathus conodont fauna with rare palmatolepids and other genera. The conodont faunas from the Bulongguoer and the Wulankeshun sections are similar, with high abundance (about 40%) of endemic taxa (13 taxa), indicating isolation of the Junggar Basin during early Famennian. Non-endemic species in the faunas suggest that the Lower Member of the Hongguleleng Formation is assignable to the Pa. rhomboidea Zone to the Pa. marginifera marginifera Zone of early Famennian, not including the Frasnian–Famennian boundary. The Upper Member may be of late Famennian–early Tournaisian in age on the basis of our preliminary faunal analysis.     

Emsian (Lower Devonian) conodonts from the Daliantang Formation at Daliantang,southeastern Yunnan,China

The lower/upper Emsian boundary witnessed prominent diversification of biostratigraphically important genera Polygnathus Hinde, Caudicriodus Bultynck, and Latericriodus Müller. In contrast, conodonts previously reported around this boundary from the South China Block were characterized by relatively low species or subspecies diversity, and only a few widely distributed and extensively studied zone-defining taxa were recorded. In this paper, conodonts from the Daliantang Formation at the Daliantang section (Guangnan, southeastern Yunnan), one of the representative sections of the transitional facies between the benthic Xiangzhou facies and the pelagic Nandan facies, are investigated. The conodont fauna shows a remarkably high species or subspecies diversity, with fourteen taxa that are assignable to the notoperbonus Zone and inversus Zone. Five polygnathid species are described: P. gronbergi Klapper and Jonson, P. inversus Klapper and Jonson, Polygnathus sp. B, P. luciae Martínez-Pérez and Valenzuela-Ríos, and P. mashkovae Bardashev. The latter two are reported for the first time from the South China Block. Additionally, three icriodontid taxa are also described, of which L. guangnanensis n. sp. is characterized by distinctly chevron-shaped transverse rows in the anterior part and a well-developed process branching off to the outer side. The new conodont record increases our understanding of the diversification and faunal composition around the lower/upper Emsian boundary in the South China Block. It contributes to the regional and inter-regional biostratigraphical correlation between shallower- and deeper-water facies and also furnishes important South China material for future discussion and deliberation on the position of the lower/upper Emsian boundary.     

Environmental changes close to the Lower–Middle Devonian boundary; the Basal Choteč Event in the Prague Basin (Czech Republic)

The Basal Chote? or jugleri Event, close above the Lower–Middle Devonian boundary, has been regarded as a minor but important eustatic transgressive event, which is characterized by significant environmental changes, faunal extinction, appearance of new forms, and maximum radiation, particularly among the goniatites. This study contributes to a more precise stratigraphic allocation of the event, and provides a reconstruction of paleoenvironmental settings in the type area of the event, the Prague Basin (Czech Republic). The beginning of a transgression is recorded already in the T?ebotov Limestone (partitus Zone, Eifelian, early Middle Devonian). The basin-wide change in the sedimentation pattern (onset of peloidal and crinoidal grainstones (calciturbidites) of the Chote? Formation) corresponding to the uppermost partitus and costatus conodont zones, base of Nowakia (Dmitriella) sulcata sulcata dacryoconarid Zone, and Pinacites jugleri goniatite Zone is interpreted here to be linked to a maximum flooding of the basin. A hypothesis of enhanced nutrient load during sedimentation of the Chote? Formation is suggested here as a triggering mechanism for intense micritization and peloid formation and prasinophyte blooms, which could be, along with a greater depositional depth, responsible for oxygen deficiency and consequent reduction of diversity and habitat tracking among benthic invertebrates.     

Revision of Famennian-Tournaisian (Late Devonian – Early Carboniferous) conodont biostratigraphy of Sardinia,Italy

Conodont biostratigraphy of the Famennian and Tournaisian of Sardinia is provided on the basis of all data available in the literature. More than 130 conodont taxa documented from this time-interval allow recognition of nineteen conodont biozones. The zonation scheme adopted here is broadly similar to the standard zonation schemes used in the Upper Devonian and Lower Carboniferous, though a few variations are needed to better accommodate the species occurrences in Sardinia: the velifer Zone and the styriacus Zone have been reintroduced, even though with slightly different meanings than previously used; the Lower praesulcata Zone is expanded to include the Middle praesulcata interval. The Upper praesulcata Zone and the sulcata Zone are missing. All zones are described and discussed and a complete list of bioevents is provided.     

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.     

A new study of Olenekian–Anisian boundary conodont biostratigraphy of the Tulong section in Himalaya Terrane,southern Tibet

The Himalaya Terrane of southern Tibet exposes successive shallow-marine carbonate deposits from the Lower to Upper Triassic, and is a key region for studying the Triassic conodont biostratigraphy at the northern margin of the Indian Plate. On the basis of newly collected samples from the Kangshare and Laibuxi formations at the Tulong section, 11 conodont species of 7 genera were identified, and four conodont zones were established, namely, the Novispathodus abruptus Zone (lower Spathian, first reported in Tibet), the Columbitella jubata Zone (middle Spathian), the Triassospathodus symmetricus Zone (upper Spathian), and the Chiosella timorensis Zone (lowermost Anisian) in ascending order. The first occurrence (FO) of Chiosella timorensis indicates the Olenekian–Anisian boundary (OAB) at Bed 25, upper part of the Kangshare Formation. The regional and global correlation of these conodont zones is synthesized.     

Uppermost Devonian–Lower Carboniferous conodonts from the Indert Formation in the Shine Jinst area,South Mongolia

In southwestern Mongolia, conodonts from the Indert Formation at its type locality in Shine Jinst were investigated to improve regional and global correlation of the uppermost Devonian–lowermost Carboniferous. The abundance and diversity of the conodont fauna is quite low in general, whereas representatives of Siphonodella, Protognathodus, Pseudopolygnathus, Polygnathus and Bispathodus have been collected from the Indert-Uul section. Five conodont biointervals, from the Bi. costatus-Pr. kockeli Interregnum (ckI) to the Siphonodella sandbergi Zone, could be recognized from the top Heermorit Member and the lower part of the Shombon Member, while the middle and upper parts of the Shombon Member cannot be zoned based on the conodonts. Absence of index fossils Si. sulcata, Pr. kuehni and Pr. kockeli hampered precise recognition of the Devonian–Carboniferous boundary (DCB) at Indert-Uul, but this transition is well delineated by typical uppermost Famennian and Tournaisian conodont assemblages. The DCB is tentatively placed at the base of the Shombon Member, consistent with the lithological boundary and the resuming of carbonate production during the DCB transitional interval.     

A new Devonian species of the enigmatic Carboniferous conodont Dollymae

Arrow-shaped P₁ elements of Dollymae are characteristic for the Tournaisian conodont faunas worldwide but the phylogeny of this conodont remains obscure and its origin is cryptic. Dollymae peregrina n. sp., from the upper Famennian (upper expansa Zone) strata in the Holy Cross Mountains (central Poland), is the oldest representative of the Dollymae lineage. The morphology of the new species’ P₁ element shows primitive features in comparison to other members of this genus and is transitional in the number of element processes. Thus D. peregrina n. sp. is most probably ancestral to the remaining species. The genus appears to be monophyletic, probably rooted in Pelekysgnathus within the Icriodontidae.     

EARLY ORDOVICIAN CONODONTS FROM TARUTAO ISLAND,SOUTHERN PENINSULAR THAILAND

Abstract: Early Ordovician conodont faunas of the Thung Song Formation on Tarutao Island, southern peninsular Thailand, consist of 14 known species belonging to 17 genera, and eight undescribed species. Utahconus tarutaoensis and Filodontus tenuis are new species. Three conodont zones: the Rossodus manitouensis Zone, the Utahconus tarutaoensis Zone and the Filodontus tenuis Zone, in ascending order, are defined in the study sections. These are coeval with the interval from the Rossodus manitouensis Zone to the Acodus deltatus‐Oneotodus costatus Zone of the standard zonation in the North American Midcontinent. Based on the conodonts studied here and fossils previously reported from Tarutao Island, the Thung Song Formation is early Tremadocian to middle Arenig (Ibexian) in age. This formation is lithostratigraphically subdivided into the S1 to S5 members, and our study sections consist of the S1 to S3 members. These strata accumulated on a shelf in the Early Ordovician. The depositional environments of the limestones making up the S1 and S3 members were in deeper‐shelf conditions. Limestone and shale of the S2 member formed in a shallow‐water, high‐energy environment.     

新疆准噶尔盆地西北缘洪古勒楞组时代的新认识

标准地点的洪古勒楞组长期以来一直被认为是准噶尔盆地西北缘,乃至整个新疆北部以海相为主的层位上最高的晚泥盆世晚期的沉积。然而牙形类和微体脊椎动物的研究证实,该组跨弗拉阶－法门阶（Ｆ－Ｆ）界线,它至少包括了一小部分弗拉晚期和主体部分为法门早期的沉积。两个牙形类带ＬａｔｅｒｈｅｎａｎａＺｏｎｅ和ＭｉｄｄｌｅｃｒｅｐｉｄａＺｏｎｅ被识别出,它们在Ｆ－Ｆ界线附近,并分别在大绝灭事件（在ｌｉｎｇｕｉｆｏｒｍｉｓＺｏｎｅ内）之前后。另一个层位更高的牙形类带ＬａｔｅｃｒｅｐｉｄａＺｏｎｅ也可能存在。同时还证实,长期以来一直被认为“正常层序”的标准地点的洪古勒楞组的层序是倒转的。由此,含植物大化石Ｌｅｐｔｏｐｈｌｏｅｕｍｒｈｏｂｉｃｕｍ等的陆相层在下（此层可能归于该组下伏的朱鲁木特组）,而产牙形类和其它丰富的无脊椎动物的海相层在上。按牙形类年代带的年代地层时间表（Ｆｏｒｄｈａｍ,１９９２）,该组距今约３６８－３６４百万年。至于它和邻近地区和布克河组的关系,由于后者发现了更高层位的牙形类,两者还不能完全对比。     

Horizon of the oldest known bryozoans (Ordovician)

Among the six species of fossil bryozoans described by Xia et al. [Xia, F.S., Zhang, S.G., Wang, Z.Z., 2007. The oldest bryozoans: new evidence from the late Tremadocian (Early Ordovician) of East Yangtze Gorges. Journal of Paleontology 81 (6), 1308–1326] from the Fenghsiang Formation of the Chenjiahe section of Yichang and the Guanzhuangping section, Liujiachang Town of Songzi, the Yangtze Gorges, Nekhorosheviella nodulifera occurs in the pristinus Conodont Subzone (lower Subzone of deltifer Conodont Zone) and the five other species are associated with the conodont Paltodus deltifer deltifer and the graptolites Acanthograptus sinensis and A. erectoramus. Based on the conodonts and graptolites, this bryofauna stratigraphically corresponds to the A. sinensis Graptolite Zone or P. deltifer Conodont Zone. The bryofauna is of Tremadocian Age (Early Ordovician) and represents the oldest bryozoans so far as known.     

New Devonian and Carboniferous bryozoans of the Holy Cross Mountains (central Poland)

New bryozoans from the Middle-Upper Devonian (Eifelian-Frasnian) and the Lower Carboniferous (Tournaisian) of the Holy Cross Mountains in central Poland are described: Bigeyella sparsa gen. et sp. nov., B. separata gen. et sp. nov., Eridopora singula sp. nov., Leptotrypa pulchra sp. nov., Kysylschinipora klarae sp. nov., Coelotubulipora rara sp. nov., Alternifenestella genuina sp. nov., Exfenestella polonica sp. nov., and Rectifenestella localis sp. nov. Some paleogeographic and stratigraphic aspects of the Paleozoic deposits of this region are discussed and main bryozoan localities are described.     

Devonian spore assemblages of China

Data available show that there are many genera and species of Devonian spores in China (together with acritarchs, chitinozoans and scolecodonts) which are commonly well-preserved, especially in South China where they are also better studied. This permits their use for correlation in detailed stratigraphical studies.On the basis of the study on Devonian spores for the past twenty years it is suggested that eight Devonian spore assemblage zones may be recognised in China, with four zones for the Lower Devonian, two zones for the Middle Devonian and two zones for the Upper Devonian. Each zone is characterised by a distinctive suite of miospores.The spore assemblages of China may be correlated basically with those in Great Britain, Federal Germany, Spitsbergen, U.S.S.R., and North America.     

Fluctuations in a late devonian-early Mississippian phytoplankton flora of Ohio,U.S.A

Fossil diversity and abundance fluctuations of Late Devonian (Famennian)—Early Mississippian (Tournaisian) phytoplankton assemblages were determined in a stratigraphic sequence of samples in Barberton test core 3, from northeast Ohio. Both diversity and abundance were relatively high during deposition of the lower Chagrin Shale (Upper Devonian) and both decreased during deposition of the upper Chagrin Shale. The overlying Cleveland Shale (Upper Devonian) is characterized by sharply increased abundance with a corresponding (although less marked) increase in diversity; in contrast, both abundance and diversity were at relatively low levels during deposition of the Lower Mississippian Bedford Shale, the uppermost unit of the sequence. These trends agree with the phytoplankton periodicity model presented by Tappan, which indicates large-scale extinction at the end of the Devonian.Many of the acritarch and prasinophycean algal taxa have restricted stratigraphic occurrences within the section studied, making them useful for local and perhaps worldwide correlation. The stratigraphically restricted taxa provide a basis for the proposal of five biostratigraphic zones within the Upper Famennian (Upper Devonian) and a portion of the Lower Mississippian. In ascending order occur: the Gorgonisphaeridium ohioense Assemblage Zone, the Acriora petala Assemblage Zone, the Muraticavea enteichia Range Zone, the Cymatiosphaera labyrinthica Range Zone, and the Navifusa drosera Assemblage Zone.     

New evidence for the Early Devonian age of the Jauf Formation in northern Saudi Arabia

Well-preserved Early Devonian continental and sparse marine palynomorph assemblages recovered from an exploration borehole located in northern Saudi Arabia are reported here and add to the understanding of Arabian Devonian stratigraphy. The units examined are the conventionally cored lower Murayr, upper Hammamiyat and Sha’iba Members of the Jauf Formation. A comparison with data sets from elsewhere on the Arabian Plate suggests that the units examined are Emsian in age. The age of the Murayr and Hammamiyat boundary interval is revised, based on the occurrence of Dibolisporites eifeliensis in northern Saudi Arabia, and placed in the Rhabdosporites minutus (Min) Interval Zone of the Emphanisporites foveolatus-Verrucosisporites dubia (FD) Oppel Zone. A new miospore, Apiculiretusispora densa with distinctive interradial thickenings, is described.     

Late Carboniferous palynostratigraphy of the Itararé Subgroup, northeastern Paraná Basin, Brazil

A new biozonation is proposed for the Late Carboniferous strata of the northeastern Paraná Basin (São Paulo and Paraná States), based on well-preserved palynological assemblages recovered from outcrops and core samples retrieved from the Itararé Subgroup. Assemblages include forty-nine species of trilete spores and twenty-five pollen species. The oldest biozone, the Ahrensisporites cristatus Interval Zone (AcZ), in the basal portion of the Itararé Subgroup, includes eleven exclusive spore species, and is assigned a Pennsylvanian (late Bashkirian to Kasimovian) age. The overlying proposed biozone, the Crucisaccites monoletus Interval Zone (CmZ), dated late Pennsylvanian (Kasimovian to Gzhelian), ranges approximately from the top of the lower portion to the middle portion of the Itararé Subgroup, bears only one exclusive species of pollen. Both zones are characterized by the dominance of trilete spores and monosaccate pollen grains, including also few taeniate pollen grains. Furthermore, the basal Protohaploxypinus goraiensis Subzone of the Vittatina costabilis Interval Zone (VcZ) is broadly recognized for the first time in the upper portion of the Itararé Subgroup in the northeastern Paraná Basin. This subzone is attributed to the Early Permian (Early Cisuralian), and is characterized by the dominance of monosaccate pollen grains, a significant increase of taeniate grains (mainly Protohaploxypinus spp.), apart from the appearance of polyplicate pollen (Vittatina spp.). Reference sections and the main characteristics of the two new zones (AcZ and CmZ) are presented, along with a preliminary palynological correlation and discussion on their ages.