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The Raheen Formation at Newtown Head in Waterford Harbour is a small isolated section of Ordovician rocks, dominated by volcanics of the Duncannon Group, but with interbedded fossiliferous shales. Although a brachiopod and trilobite dominated fauna has been known since the mid-nineteenth century, only the trilobites and cystoids have been assessed in modern terms. This paper describes the brachiopod fauna for the first time. The assemblage from Raheen is overwhelmingly dominated by the dalmanelloid Onniella, with the small plectambonitoid Sericoidea comprising the second most numerous species; both are represented by new species. This revision has also identified a wide range of other genera, but all in very small numbers. These include an obolid, a paterulid, Paracraniops and Orthisocrania divaricata (M‘Coy) amongst the non-articulated brachiopods. Articulated genera present include the orthoids Nicolella, Ptychopleurella, Sulevorthis, Skenidioides and the plectambonitoid Leptestiina. Very rare forms include Idiospira? and Palaeostrophomena, together with possibly Biscuspina and Sowerbyella. The brachiopod revision supports the late Caradoc (early Katian) age indicated by the trilobite fauna. The trilobite fauna generally indicates a probable deeper-water environment and the brachiopod assemblage confirms an outer-shelf environment. Although elements of the assemblage indicate affinity with the well-defined Late Ordovician Foliomena fauna, it probably occupied a more shoreward position. (Less)

An exceptionally preserved noncalcified thallophytic alga, Menieria minuta gen. nov. et sp. nov. from the uppermost Gun River Formation (middle Aeronian, Lower Silurian) of Anticosti Island, eastern Canada, is characterized by a relatively delicate thallus with a central axis, lateral branches, and helically arranged, regularly and closely spaced, elongate-linguoid appendages. The algae locally constitute an important portion of the biomass in a brachiopod-dominated paleocommunity, forming an algal meadow on a relatively deepwater subtidal setting within the photic zone. This rare fossilization window suggests that such soft algal meadows may have been common during the Early Paleozoic, resembling modern sea grass meadows that are part of the carbon sink.

The upper Daguanshan Formation (middle Ex- pansograptus hirundo graptolite biozone, Dapingian, early Middle Ordovician) of the Shuanghe area, Changning County, southern Sichuan Province, contains three new gen- era and species of strophomenoids: Ochyromena plana, Shuangheella elongata, and Primotimena globula, which are attributed to the Strophomenidae, Rafinesquinidae and Gly- ptomenidae respectively. These are the earliest known strop- homenoids from the South China palaeoplate, and also the oldest rafinesquinid and glyptomenid brachiopods world- wide. 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 Kazakh- stan, Iran, and Baltica (early Darriwilian), to Avalonia and Laurentia (late Darriwilian). This points to the existence of early diversification hotspots of the strophomenoid super- family in the North and South China palaeoplates during the early Middle Ordovician in generally shallow water (corre- sponding to BA2) environments. The high degree of similar- ity 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 pro- cess, a key evolutionary novelty for the strophomenoids.

Eospirifer, the oldest known genus of the spiriferide group (Brachiopoda), first appeared on the Zhe-Gan Platform of South China paleoplate during late Katian (Late Ordovician) represented by E. praecursor. It survived the end-Ordovician mass extinction, and reappeared on the Upper Yangtze Platform of South China paleoplate by the end of Ordovician near the upper part of the Normalograptus persculptus Biozone. Starting from the beginning of Silurian, Eospirifer experienced some morphological innovations and expanded its geographical distribution substantially. It reached its species diversity acme and the widest geographic distribution in Wenlock (middle Silurian), with the diversity hotspots in Laurentia, Avalonia, and Baltica. Various shell size frequency curves of E. praecursor under different paleogeographic settings suggest that this pioneer species of Eospirifer, with several macroevolutionary novelties, adopted a range of life strategies to adapt to the changing environments during early spiriferide evolution. There are also some morphological macroevolutionary trends during the evolutionary history of Eospirifer from Late Ordovician to the end of Silurian, such as the ever enlarging shell sizes and the width/length ratios from late Katian to Wenlock, but decreasing apparently of both parameters from Wenlock to Pridoli.

A collection of numerous crinoid pluricolumnals from the uppermost Darriwilian (Middle Ordovician) of Tibet were derived from one biological species of crinoid. The specimens were collected from well-lithified, bioclastic shelf limestones of the upper part of the Lower Chiatsun Group, Pygodus serra Biozone; coeval rocks of similar lithology outcrop at the summit of Everest. A new crinoid morphospecies, Segmentocolumnus (col.) hanshessi, is tentatively considered a ‘stem-group cladid’, perhaps a dendrocrinid. The proxistele is broad and pentagonal in section with a broad, pentagonal axial canal; the mesistele of similar gross morphology is more slender with a regularly heteromorphic column and a similarly wide axial canal; the dististele is a terminal dendritic radice with a pentastellate axial canal. In the mesistele, the meric sutures correspond to the centres of the sides of the column, but in the dististele they occur in the angles. This range of morphologies would have led to their inclusion in at least two morphogenera if they had not been closely associated; as they belong to a single biological species, they have been ‘lumped’ together herein. This is a rare contribution to our knowledge of the early crinoids from a region outside Europe and North America. Copyright © 2012 John Wiley & Sons, Ltd.

A continuous Ordovician-Silurian boundary section from the upper Wufeng Formation through the Kuanyinchiao Formation to the lower Lungmachi Formation has been carefully measured and collected at Shuanghe of Changning, southern Sichuan Province. For the first time, the temporal changes of alpha- and beta-diversities of the Hirnantia fauna have been discussed in great detail. The general trend of brachiopod diversity change, increasing upward, is consistent with the regional trend of the Yangtze Platform, which had been controlled by both intrinsic and extrinsic factors. However, the sudden drop of diversity for a short period in the upper Kuanyinchiao Formation might have been controlled by environmental factors rather than normal faunal turnover. Synecological analysis using numerical methods recognizes two brachiopod-dominated associations of the Hirnantia fauna, the Dalmanella-Kinnella Association and the Mirorthis Association, both living in an offshore, deeper water environment corresponding to BA3-upper BA4, particularly lower BA3.

The brachiopod fauna of the upper Cambrian (upper Furongian) Guole Formation, northwestern Jingxi County, southwestern Guangxi Province, southern China, comprises six genera and seven species, including one new genus, three new species and two indeterminate species (Obolidae gen. et sp. indet, Acrotretidae gen. et sp. indet., Billingsella guangxiensis, B. costata sp. nov., Guoleella lata gen. et sp. nov., Palaeostrophia jingxiensis, Plectotrophia imparicostata sp. nov.). This is the first systematic description of an upper Cambrian brachiopod fauna composed mainly of calcareous-shelled individuals from China. Brachiopod and trilobite faunal analyses suggest that this fauna has a prominent North American (Laurentian) affinity. It is notably different from the coeval, lingulate-dominated brachiopod fauna of South China, particularly of the Yangtze Platform, but shares some similarity with those of the North China Platform. Preliminary analysis reveals that this brachiopod fauna, named the Billingsella-Palae...

Re-examination of newly collected topotype material confirms that the type species of Yangtzeella, Y. po- loi, a widespread Early and Mid Ordovician syntrophiidine brachiopod in South China, has a finely costellate shell rather than being smooth as previously thought. Thus, the subgenus Yangtzeella (Vadimella) Nikitina et al., established on the basis of fine costellae, is invalidated. Among 15 species of Yangtzeella, five species are recognized as valid based on multivariate analyses: Y. poloi, Y. unsulcata, Y. songziensis, Y. kueiyangensis and Y. igori, among which the type species was the oldest known. Six are synonymized: Y. septata, Y. reticulata, Y. lensiformis, Y. depressa, Y. yichangensis and Y. minuta. Four are rejected from Yangtzeella: Y. extensa, Y. similior, Y. yohi and Y. poloi var. minor. Regional biostra- tigraphy indicates that Yangtzeella first appeared in a rela- tively deep-water setting on the Lower Yangtze Platform (South China palaeoplate) during late Tremadoc time (Sco- lopodus warendensis conodont biozone) and then expanded to the deeper Jiangnan Slope as well as to the shallower Upper Yangtze Platform. The genus experienced two epi- sodes of heightened abundance and diversity on the Upper Yangtze Platform during late Dapingian and mid Darriwilian times, respectively. Outside South China, Yangtzeella occurs sporadically in a few microplates or terranes, such as Tarim, Chu-Ili (southern Kazakhstan) and Taurides (southern Turkey) during the Dapingian and Darriwilian. Worldwide, Yangtzeella became extinct by the end of the Darriwilian.

The temporal distribution of the diagnostic biofabrics in the Lower and Middle Ordovician in North China distinctly illustrates that the sedimentary systems on the paleoplate have been changed markedly as consequences of the Great Ordovician Biodiversification Event (GOBE). The pre-GOBE sedimentary systems deposited in Tremadoc display widespread microbialite and flat-pebble conglomerates, and a less extent of bioturbation. Through the transitional period of early Floian, the sedimentary systems in the rest of the Early and Mid- Ordovician change to GOBE type and are characterized by intensive bioturbation and vanishing flat-pebble conglomerates and subtidal microbial sediments. The irreversible changes in sedimentary systems in North China are linked to the GOBE, which conduced the increase in infaunal tiering, the expansion of infaunal ecospace, and the appearance of new burrowers related to the development of the Paleozoic Evolutionary Fauna during the Ordovician biodiversification. Thus, changes in sedimentary systems during the pivotal period of the GOBE were consequences of a steep diversification of benthic faunas rather than the GOBE's environmental background.

A silicified brachiopod fauna from the Middle Ordovician Kuniutan Formation (lower-middle Darriwilian, i.e. uppermost Arenig to lower Llanvirn) at Wudang, Guiyang, central Guizhou, South China, includes abundant specimens of Yangtzeella, Orthambonites and Leptellina together with common Parisorthis, Saucrorthis, rare Anoma- lorthis?, Hemipronites?, Leptestia? and, significantly, Aportho- phyla; associated are rare trilobites, gastropods, crinoids and nautiloids. The Yangtzeella kueiyangensis-Orthambonites delicata Association is defined for this shallow-water, Benthic Assemblage 3, association. This first record of Aporthophyla in South China may indicate a link between South China and the Toquima-Table Head Province, where the Aporthophyla fauna is more typically developed. How- ever, this association is significantly different from the lat- ter in having three endemic genera, Yangtzeella, Saucrorthis and Parisorthis, rare numbers of Aporthophyla and Anoma- lorthis?, and the absence of many other typical elements of the Aporthophyla fauna. The occurrence of Orthambonites, Hemipronites? and Leptestia? suggests some relationships between South China and the Baltic Platform during the Mid Ordovician. The various brachiopod associations bearing Aporthophyla may be quite different in nature, composition and diversity, and may possess different back- ground palaeobiogeographical signatures. The assemblages containing Aporthophyla in South China, Qaidam, Malaysia, Australia and possibly Tibet are clearly different biogeo- graphically from those associated with the Toquima-Table Head and the Celtic provinces. Two new species, Aportho- phyla sinensis sp. nov. and Leptellina orientalis sp. nov. are described.

Late Ordovician to earliest Silurian is an important geological period marked by large geological and biological events. However, the strata and fossils of this interval are not complete in many parts of the world. Based on studies of 43 sites in South China, in particular the continuous sections on the Yangtze platform, we recognize a complete succession including seven graptolite zones and two shelly faunas. In ascending order, the graptolite zones are the Dicellograptus complanatus, Dicellograptus complexus, Paraorthograptus pacificus (including Lower Subzone, Tangyagraptus typicus Subzone and Diceratograptus mirus Subzone), Normalograptus extraordinarius–Normalograptus ojsuensis, Normalograptus persculptus, Akidograptus ascensus and Parakidograptus acuminatus zones. The shelly faunas are the Foliomena–Nankinolithus and Hirnantia faunas, which may be correlated with D. complanatus Zone and N. extraordinarius–N. ojsuensis to part of N. persculptus zones respectively. The biozonation through this interval from the Yangtze region can be correlated with that of other parts of the world such as Dob's Linn in Scotland, Spain and Portugal, Thuringia–Saxonia–Bavaria, Bohemia, Poland, Kazakhstan, Kolyma, Malaya Peninsula, Yukon, Canadian Arctic Islands, Nevada, Argentina, Niger and Victoria, Australia. The Hirnantian Substage, which has been proposed by us recently, includes the N. extraordinarius–N. ojsuensis Zone, Hirnantia fauna and N. persculptus Zone. The base of the Hirnantian Substage is marked by the First Appearance Data (FADs) of N. extraordinarius and N. ojsuensis, which have been determined to be synchronous on a global scale.

Eospirifer praecursorn. sp. is the oldest known eospiriferine, probably ancestral to the entireSpirifergroup. It is described here based on external and internal mold material from the uppermost part of the Changwu Formation (mid-Ashgill, Late Ordovician), Hejiashan, Jiangshan, western Zhejiang, East China. A study of the ontogeny ofE. praecursorn. sp. suggests that the cardinalia of early growth stages are more similar to those of early atrypoids rather than to those of the orthoids but the brachidia in these earliestEospiriferare still unknown. The possibility that eospiriferines were derived from an atrypoid stock cannot be excluded. All early eospiriferine species recorded from the Ashgill, Rhuddanian, and early Aeronian are reviewed for comparison. Their morphological diversification reveals early evolutionary experimentation. Based on the Ashgill occurrence ofEospirifer, it is likely that East Asia may be considered as one of the eospiriferine source areas.

Species-abundance models have been an important method for investigating community structure in modern biology in the past decades. Different species-abundance models can reflect different ecological meanings. The method is relatively new to palaeoecology. We take the latest Ordovician-earliest Silurian Cathaysiorthis brachiopod fauna of South China as an example, program the calculation in the R language, introduce the application of the species-abundance models and discuss the relationship between the abundance model and the ecological bathymetry of a certain brachiopod fauna. Finally, we testify the validity of the method and suggest that the species-abundance models should be treated as one of the supporting evidences in investigating the brachiopod palaeoecology.