LATE ORDOVICIAN BRACHIOPODS FROM THE DULANKARA FORMATION OF THE CHU-ILI RANGE, KAZAKHSTAN: THEIR SYSTEMATICS, PALAEOECOLOGY AND PALAEOBIOGEOGRAPHY

Abstract:  Brachiopods from the late Ordovician (late Caradoc) Dulankara Formation of the Chu-Ili Range, Kazakhstan, are reviewed. Those from the upper two members of the formation, the Degeres and Akkol members, are systematically described. New genera from the Dulankara Formation are Nikitinamena (Plectambonitoidea: Leptellinidae), with type species Nikitinamena bicostata sp. nov., and Weberorthis (Orthoidea: Plectorthidae), with type species Mimella brevis Rukavishnikova. Another new genus is Glyptomenoides (Strophomenoidea: Glyptomenidae), with type species Rafinesquina girvanensis Salmon from the Caradoc of Girvan, Scotland. Other new species from the Dulankara Formation are Holtedahlina orientalis , Platymena tersa , Christiania proclivis , Leangella ( Leangella ) paletsae , Metambonites subcarinatus , Ogmoplecia nesca and Plectorthis licta . The ecology and assemblages of all three members of the Dulankara Formation are identified or reviewed, and their palaeogeographical significance assessed: the Chu-Ili Terrane (on which the Dulankara Formation was situated during the Ordovician) formed part of the relatively low-latitude peri-Gondwanan complex of terranes, and was probably not far from North and South China. The faunal links suggested between the Dulankara brachiopods and contemporary faunas from Australia are now perceived to be weaker than previously thought.     

WUCHIAPINGIAN (LOPINGIAN, LATE PERMIAN) BRACHIOPODS FROM THE EPISKOPI FORMATION OF HYDRA ISLAND, GREECE

Abstract:  Twenty-three species of silicified brachiopods are described from four samples in the middle and upper parts of the Episkopi Formation from Hydra Island, Greece. These brachiopods are newly recorded from the region and together with previously described brachiopods from the same localities constitute the most diverse Lopingian (Late Permian) brachiopod fauna reported in southern Europe. The brachiopod fauna is Wuchiapingian as indicated by the associated conodonts. The fauna from Hydra exhibits strong palaeobiogeographical links with the faunas from South China. In addition, palaeobiogeographical affinities with the faunas of Thailand and the northern peri-Gondwanan region are also present, which implies a peri-Gondwanan origin for Hydra. Palaeoecologically, the brachiopod assemblage from sample EP in the middle part of the Episkopi Formation is dominated by pedically-attached and cementing genera and reflects moderate energy conditions above storm wave base and an abundance of hard substrates provided by sponges in the biohermal habitat. By contrast, the brachiopod assemblage in the other three samples from the upper part of the Episkopi Formation is dominated by spinose genera with a free-resting life habit, suggesting soft substrates in a quiet water environment below storm wave base on the outer part of the shelf. New taxa are Petinospiriferina gen. nov., Hustedia episkopiensis sp. nov., Waterhouseiella hydraensis sp. nov. and Xenosaria tenuis sp. nov.     

Late Ordovician brachiopods from eastern North Greenland: equatorial offshore migration of the Red River fauna

Abstract: Late Ordovician rhynchonelliformean brachiopods, typical of the North American Red River fauna, are found sporadically in the Børglum River Formation of the Centrum Sø area, Kronprins Christian Land, eastern North Greenland. The geographical distribution of this characteristic brachiopod fauna is thus extended to the easternmost extremity of the Laurentian craton. The assemblage compares specifically with the Hiscobeccus brachiopod fauna, based on key taxa such as notably Hiscobeccus gigas (Wang, 1949), and indicates a late Katian age for this part of the succession. For the first time, this typically inland, shallow‐water fauna is found associated with genera like Bimuria, suggesting a transitional marginal facies with outer shelf benthos. The current study describes a Hiscobeccus fauna that lived at the seaward edge of its preferred habitat. Furthermore, an unpublished Hiscobeccus fauna, from the Børglum River Formation of Peary Land, central North Greenland, as well as several occurrences from the Kap Jackson and Cape Calhoun formations in various parts of Washington Land, western North Greenland, are described here. These show a distinct shift from older strata containing H. capax (Conrad, 1842) to younger strata exclusively yielding specimens of H. gigas. As H. gigas occurs in the upper part of the Cape Calhoun Formation in Washington Land, it indicates that the upper boundary of the Cape Calhoun Formation is considerably younger than previous estimates, reaching into the uppermost Katian (middle Cautleyan–Rawtheyan). The Cape Calhoun Formation correlates with the upper member of the Børglum River Formation and further demonstrates that the Hiscobeccus fauna was widespread in Laurentian marginal settings of North Greenland. Even though the Hiscobeccus fauna was pan‐continental during the late Katian (Richmondian), it possesses a strong provincial signal during the later Ordovician. The new occurrences indicate that this fauna extended to the north‐eastern margin of the Laurentian Craton. It lived in close association with cosmopolitan faunal elements that may have been the earliest sign of the succeeding invasion of migrants from Baltica that arrived later during the Hirnantian. The offshore migration of this atypical Hiscobeccus fauna likely demonstrates the path of warm‐water currents as the Centrum Sø locality was located at the equator during the Late Ordovician.     

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.     

The earliest known strophomenoids (Brachiopoda) from early Middle Ordovician rocks Of South China

The upper Daguanshan Formation (middle Expansograptus hirundo graptolite biozone, Dapingian, early Middle Ordovician) of the Shuanghe area, Changning County, southern Sichuan Province, contains three new genera and species of strophomenoids: Ochyromena plana, Shuangheella elongata, and Primotimena globula, which are attributed to the Strophomenidae, Rafinesquinidae and Glyptomenidae respectively. These are the earliest known strophomenoids from the South China palaeoplate, and also the oldest rafinesquinid and glyptomenid brachiopods worldwide. Global review of the superfamily Strophomenoidea of Middle Ordovician age suggests that the first diversity peak at the species level occurred in late Darriwilian (Llanvirn) time, mainly as a result of the rapid diversification of the family Strophomenidae. The first appearance datum (FAD) of strophomenoids and their possible westward dispersal were from North China (latest Floian) and/or South China (early Dapingian), through the Chu‐Ili terrane of Kazakhstan, Iran, and Baltica (early Darriwilian), to Avalonia and Laurentia (late Darriwilian). This points to the existence of early diversification hotspots of the strophomenoid superfamily in the North and South China palaeoplates during the early Middle Ordovician in generally shallow water (corresponding to BA2) environments. The high degree of similarity in the external morphology and ventral interior of the three new genera indicates that the early diversification of strophomenoids began with differentiation of the cardinalia, especially in the configuration of the bilobed cardinal process, a key evolutionary novelty for the strophomenoids.     

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.     

Evolution of the Rhynchotrema–Hiscobeccus lineage: implications for the diversification of the Late Ordovician epicontinental brachiopod fauna of Laurentia

Multivariate analysis based on nine biometric characters of 171 Late Ordovician rhynchonellide specimens from nine upper Sandbian–upper Katian localities in North America supports the hypothesis that one of the diagnostic taxa of the North American epicontinental brachiopod fauna, Hiscobeccus, evolved from Rhynchotrema, which lived predominantly in peri‐cratonic settings. The oldest known Hiscobeccus, H. mackenziensis of early Katian age, exhibits transitional characteristics between Rhynchotrema and Hiscobeccus, and it clusters more closely with Rhynchotrema than with younger species of Hiscobeccus of mid–late Katian (Maysvillian–Richmondian) age. Diversification of the Hiscobeccus lineage in epicontinental seas was characterized by drastic increase in shell size, globosity and lamellosity, especially in palaeoequatorially located inland basins. Such morphological trends are interpreted as adaptation to relatively shallow, muddy substrates, moderate water turbulence, relatively low oxygen content and unstable supply of nutrients in generally overheated epicontinental seas with sluggish circulation.     

Discovery of a Late Ordovician Foliomena fauna in the Tarim desert,Northwest China

A Foliomena fauna is reported for the first time from the Tarim paleoplate, and stratigraphically from the Yinpingshan Formation (upper Katian, Upper Ordovician) of Querqueke, Kuruktag region, northeastern Tarim, southern Xinjiang, Northwest China. The fauna includes seven species of brachiopods, amongst which three are new and four indeterminate: Anomaloglossa? sp., Orbiculoidea? sp., Foliomena xinjiangensis n. sp., Sericoidea minuta n. sp., Kassinella tarimensis n. sp., Rostricellula? sp., and Anazyga? sp. These species formed a Sericoidea-Kassinella Association, characterized by very small and well-preserved brachiopods, and well-developed laminations in its hosted mudstone, indicating a deep water environment (corresponding to lower BA5 to BA6). The faunal and sedimentological features suggest its affinity to the typical Foliomena faunal group of deep water origin. Numerical analyses show that the Foliomena fauna in late Katian time differentiated into two major paleogeographically related groups, and the Tarim association has a close faunal affinity to the representatives of this fauna in South China, indicating an active faunal exchange between Tarim and South China before the end-Ordovician mass extinction.     

A new late Katian (Late Ordovician) trilobite association from Zhenxiong,northeastern Yunnan,Southwest China and its palaeoecological implications

A new late Katian (Late Ordovician) trilobite association is documented from the Daduhe Formation in Zhenxiong, northeastern Yunnan, including 17 species of 15 genera, among which four species (Malongullia sinensis, M. zhenxiongensis, Taklamakania paucisegmentatus and Amphitryon constrictus) are new. Lithologic and faunal evidence enables the recognition of a new association with medium diversity, named the Taklamakania Association. It is a typical representative of the Raphiophorid Community that lived in a deep subtidal environment close to the anoxic basin. A total of five trilobite ecological associations were found to occur in South China during the late Katian, in relation to the environmental gradients ranging from shallow subtidal zone, deep subtidal zone, slope to dysoxic shaly basin.     

Middle–Late Ordovician chitinozoans from Songliang of Qiaojia,western South China,and their biostratigraphic implications

Ordovician chitinozoans are as yet inadequately documented from the western Yangtze Platform, South China. Here we present a systematic study on chitinozoans from a Middle–Upper Ordovician succession at Songliang of Qiaojia, northestern Yunnan, southwestern China. Altogether 34 species of 12 genera are identified from the upper Hungshihyen and the Huadan formations. The top of the Hungshihyen Formation yields typical Early and Middle Ordovician forms, for instance, Lagenochitina obeligis and Belonechitina chenjiawuensis, with the latter only known from the lower Darriwilian in South China, thus suggesting an early Darriwilian age for this interval. The chitinozoans recovered from the Huadan Formation include Lagenochitina prussica and Spinachitina fossensis, both are mainly confined in Katian and sometimes ranging into younger strata. This indicates an age younger than the middle to late Darriwilian previously determined for the Huadan Formation. However, conflicts exist in age assignment of the Huadan Formation based on chitinozoan and other evidence, and further work is required.     

Givetian Stringocephalid brachiopods from eastern Yunnan of Southwest China with notes on global distribution of the family Stringocephalidae

Stringocephalid brachiopods are widely known in the Givetian, but little knowledge is obtained concerning their palaeobiogeographical patterns globally, therefore further studies with new updates and details are required. In this paper, we describe two new stringocephalid brachiopod genera: Yangirostra asiatica n. gen. n. sp. (subfamily Stringocephalinae) and Chinellirostra rara n. gen. n. sp. (subfamily Bornhardtininae), and a new species Stringocephalus sinensis n. sp., together with an indeterminate species Parastringocephalus sp., from the Givetian (late Middle Devonian) of eastern Yunnan, Southwest China. Moreover, with information of the stringocephalides from North Africa, Alaska, North America, Europe and Northeast Eurasia, we compile a dataset of family Stringocephalidae containing 32 genera in 7 subfamilies globally. Based on our data, subfamily Stringocephalinae brachiopods show cosmopolitism and considerably wide distribution from Siberia to the northern Gondwana margins (i.e., North Africa and Australia). Nevertheless, the Boreal Realm and Palaeotethyan Realm are depicted in this paper at the subfamily level, which is much different from the previous palaeobiogeographical schemes in the Givetian. Furthermore, palaeobiogeographical links between Siberia, the Urals and western North America (Alaska, Canada, Nevada and Sonora) are confirmed by diversification of the subfamilies Omoloninae and Rensselandiinae. Whereas in Eurasia (i.e., western and eastern Europe, North and South China), many endemic species of the subfamilies Bornhardtininae and Geranocephalinae are present, as well as the Kaplexinae and Leioseptathyridinae.     

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.     

Surviving the end-Ordovician extinctions: evidence from the earliest Silurian brachiopods of northeastern Jiangxi and western Zhejiang provinces, East China

Earliest Rhuddanian (Silurian) brachiopods are recorded from the basal part of the Lower Llandovery Shiyang and Anji formations in western Zhejiang and northeastern Jiangxi provinces, East China. Associated graptolites including Normalograptus jerini indicate the lowest Rhuddanian Akidograptus ascensus Biozone. The surviving brachiopod fauna includes 19 genera dominated by orthids and strophomenids, whereas pentamerids and atrypids that inhabited mainly warmer water regimes, and were almost absent in the cool/cold Hirnantia Fauna, occur rarely in the studied fauna. Each family is represented by a single genus that seeded their recovery. The predominance of these long-ranging and widely distributed genera is one of major characters of the brachiopod survival in east China. From qualitative and quantitative analysis of faunal composition, diversity and abundance, with evidences from palaeoecology and palaeogeography, the Levenea qianbeiensis Association, Katastrophomena-Leptaena-Levenea Association, and Glyptorthis-Epitomyonia-Levenea Association are recognized and assigned to BA (Benthic Assemblage) 2, BA3, and an ecozone close to the BA3-4 boundary respectively. No Lazarus genera are recorded in this study. Skenidioides and Epitomyonia were chiefly regarded as deeper-water taxa in the Ordovician and Silurian, but are recorded from shallow-water in east China during the early Rhuddanian, indicating an ecologic experiment with these taxa migrating from deep into shallower, better-oxygenated sites at the crisis time and during the subsequent survival interval. This study further demonstrates that the brachiopod faunal turnover after the end-Ordovician extinctions may not have been completed until the late Rhuddanian in South China.     

简论相似性测度的选择——以奥陶纪末大灭绝后全球腕足动物古地理为例

灭绝事件对古生物地理格局的影响已引起关注,近期研究表明奥陶纪末大灭绝事件后多样性显著高于传统认识,而全球该时期腕足动物的古生物地理分布情况尚未见报道。本文基于已发表的和最新的资料及所掌握新数据的整理,建立全球腕足动物志留纪初鲁丹(Rhuddanian)早期（残存期）13个产地72属137个出现信息(occurrence...     

安徽石台奥陶纪弗洛期—大坪期牙形刺多样性的演变

基于安徽石台栗阳柳树亭下、中奥陶统紫台组牙形刺的系统研究,对该地区早奥陶世弗洛期一中奥陶世大坪期牙形刺多样性演变作了初步分析,发现牙形刺的简单分异度在弗洛晚期Oepikodusevae带达到峰值,有17属20种。之后,牙形刺分异度呈下降趋势。演变的总体趋势与湖北宜昌地区同期牙形刺的研究结果一致,其峰值出现的时间（Oepikodusevae带,相当于笔石Didymograptellus eobifidus带上部,Corymbograptusdeflexus带,及Azygograptussuecicus带下部）与华南上扬子区腕足动物宏演化趋势（首次峰值出现在Didymograptelluseob—ifidus带）大体相似,但比三叶虫多样性演变在奥陶纪的首次峰值（出现在Exigraptus clavus带）早,比扬子台地笔石多样性演变的首次峰值（在Acrograptusfiliformis带和Didymograptelluseobifidus带下部）晚。分析显示,该地区早、中奥陶世牙形刺多样性演变与海平面变化存在密切关联。     

The late Sandbian – earliest Katian (Ordovician) brachiopod immigration and its influence on the brachiopod fauna in the Oslo Region, Norway

Bulk samples of brachiopods from the middle and upper parts of the Arnestad Formation and the entire Frognerkilen Formation in the Oslo Region demonstrate major vertical changes in the Sandbian to Katian amphicratonic fauna of this part of the Baltic Province. The main influx of new taxa occurred in the upper part of the Arnestad Formation (uppermost Sandbian), and in the succeeding Frognerkilen Formation (basal Katian). Faunal change is initially reflected in an increase in diversity and not as a replacement of the previously incumbent genera, which remain throughout the studied sequence. The majority of the new genera migrated from the East Baltic Region or through this region from Avalonia, while the marginal Laurentian taxa first occupied the Scandinavian part of Baltica. Six taxa migrated from Laurentia, three from Avalonia, two from Gondwana and one apparently originated on the South China palaeoplate. The faunal shifts and immigration of brachiopods appear to have been in response to an initial transgression together with the movement of Baltica into more warm temperate latitudes, but the diverse faunas developed both against a background of subsequent regression and in response to an offshore shift of biofacies. The new amphicratonic fauna was thus generated by faunal shifts from elsewhere in the Baltic Province to the marginal environments of the Oslo Region together with more exotic elements from neighbouring continents and microcontinents.     

The Cenozoic Brachiopods of the Carnarvon Basin, Western Australia

The Paleocene-Miocene deposits of the Carnarvon Basin of Western Australia contain a rich fauna of brachiopods, but only two species, Tegulorhynchia boongeroodaensis Westralicrania allani , both from the Paleocene, have previously been described.One new genus, Giraliathyris , and eight new species are described herein. They are Giraliathyris mcnamari, G. kaitrinae, G. jubileensis, Liothyrella longorum, Victorithyris decapello, V. cardabiaensis, V. blakeorum, V. tulkiensis, Diedrothyris cf. johnstoniana Paraldingia timi . A Terebratulina species and two species of indeterminate genera are also described. Basiliola (Rhynchonellida) and Cancellothyris (Terebratulida) are recorded for the first time from the upper Paleocene of Australia. These, together with Victorithyris Diedrothyris Liothyrella and Paraldingia , represent the oldest records of these genera. It is suggested that their early occurrence, together with those known from the Antarctic Peninsula, indicates a southern origin for this fauna and a high latitude, southern circum-Indo-Atlantic faunal province is proposed. Subsequently the brachiopod fauna spread northwards towards lower latitudes and west to east around southern Australia, before and during the development of the circum-polar current during the Oligocene.     

BILLENGSELLIDE AND ORTHIDE BRACHIOPODS: NEW INSIGHTS INTO EARLIEST ORDOVICIAN EVOLUTION AND BIOGEOGRAPHY FROM NORTHERN IRAN

Abstract:  The eastern Alborz Mountains of Iran comprise a significant peri-Gondwanan terrane relevant to the early evolution of late Cambrian – early Ordovician brachiopods incorporated into the emerging benthic biota of the Paleozoic Evolutionary Fauna. A low diversity brachiopod assemblage from the late Tremadocian unit of the Lashkarak Formation contains six new species including the polytoechioideans Polytoechia and Protambonites and the orthoideans Paralenorthis, Ranorthis, Tarfaya and Xianorthis . The fauna preserves the earliest records of Polytoechia , unknown previously outside Laurentia and the Uralian margin of Baltica, and of Paralenorthis and Ranorthis , which were widespread along Gondwanan margins and in Baltica from the Floian (Arenig), plus Xianorthis , known hitherto only from the Floian of South China. The enigmatic Tarfaya has an impunctate shell fabric and setigerous perforations along the posterior margin, indicating placement within the Orthoidea in a new Family Tarfayidae. New species of Polytoechia , Protambonites , Paralenorthis, Ranorthis , Tarfaya , Xianorthis are described.