Rugose corals from the Upper Ordovician Sholeshook Limestone of southwest Wales with an assessment of the coral affinities and biofacies

Limestone horizons of Upper Ordovician (Katian) age in southwest Wales contain diverse fossil faunas including rugose corals. The existence of Ordovician Rugosa in Wales was first reported by Murchison in the 1830s, but since then hardly any specimens have been documented systematically until this present study. Newly collected material from the area around Llanddowror (Carmarthenshire) has now confirmed the diversity of rugose corals in the Sholeshook Limestone (Katian age), an arenaceous limestone originating from the shelf edge of the palaeocontinent Avalonia. The majority of the specimens are preserved as moulds. This means that in many instances preservation of the fossils was insufficient for specific identification; nevertheless, it was possible to document a diverse rugose coral fauna, including Helicelasma, probable Grewingkia and Kenophyllum, and a potential early mucophyllid. While associated with considerable difficulties, as some diagnostic features of Rugosa are not visible in moulds, it is demonstrated here that the work with such specimens can result in faunal information which would otherwise be unobtainable. An assemblage of rugose and tabulate corals in the Sholeshook Limestone can be differentiated from a similar assemblage in the neighbouring Robeston Wathen Limestone which has a slightly different lithology. The fauna has strong similarities with other Avalonian (Irish, English, Belgian) as well as Baltic (Estonian and Norwegian) rugose coral faunas. Copyright © 2012 John Wiley & Sons, Ltd.     

Frasnian rugose and tabulate corals from the eastern Taurus (Kozan region,Turkey)

A section near the Kilgen Lake (Adana Province) has yielded a fauna of rugose and tabulate corals including Disphyllum cf. rugosum (Wedekind, 1922), D. cf. curtum Hill, 1954, Wapitiphyllum sp., Thamnopora sp., and Alveolites sp. This coral assemblage is consistent with the previous Frasnian age assigned to the limestones of the Gümü?ali Formation. The rather well-preserved material provides new data on the structure and microstructure of Disphyllum and allows to describe in Thamnopora unusual calicinal morphology (septal ridges, median teeth, and pseudopercula) as well as new structures linked to the lateral increase (basal low wall, apical cul-de-sac).     

Combination Features, Paleobiogeographic Affinity and Mass Extinction of the Latest Ordovician （Hirnantian） Rugosan Fauna from Northern Guizhou, China

The rugosan fauna from the Guanyinqiao Bed （latest Ordovician, Hirnantian） of northern Guizhou, China is known to belong to the cold or cool-water type corals. The components of the fauna are solitary corals only, and corallite septa are generally strongly dilated, especially the streptelasmatid corals are dominant comprising 98% of the whole fauna. The Guanyinqiao Bed is rich in rugosans of 18 genera, which are streptelasnmtid Streptelasma （=Helicelasma）, Brachyelasma, Amplexobrachyelasma, Salvadorea, Grewingkia, Borelasma, CrassUasma, Leolasma, KenophyUum, UUernelasma, Paramplexoides, Siphonolasma, Pycnactoides, Dalmanophyllum, Bodophyllum, Axiphoria, Lambeophyllum and cystiphyllid Sinkiangolasma. Although this fauna was fairly abundant in a confined area （northern-northeastern Guizhou, southern Sichuan） during the Hirnantian age, the rugosan mass extinction （generic extinction rate 81%） happened at the end of the Hirnantian Stage. It is conduded that the mass extinction is related to the ending of maximum glaciation and ice cap melting in Gondwana in the southern hemisphere in the latest Hirnantian, resulting in rapid global sea-level rise in the earliest Silurian. In the Upper Yangtze Basin, the sea bottom environments were replaced by anoxic and warmer water during that time, so that the cool-water type rugosan became extinct. The present paper attempts to revise some already described rugose coral genera and species （He, 1978, 1985） and to supplement a few new forms from the Guanyinqiao Bed. Fourteen species of 12 genera are re-described and illustrated, of which one species- Grewingkia latifossulata is new. As a whole, the rugosan fauna of the Guanyinqiao Bed may be correlated with those contemporaneous of North Europe, Estonia and North America, indicating a dose biogeographic affinity to North Europe.     

唐山—秦皇岛地区晚石炭世的皱纹珊瑚

研究区位于华北板块的东北部 ,晚石炭世为海陆交互相沉积。海相灰岩层中产有大量珊瑚、竹蜓 、腕足类及双壳类化石。共描述皱纹珊瑚 7属 15种 ,其中新种 11个 ,1个未定种。珊瑚化石组合中 ,小型单体珊瑚、中大型单体珊瑚和群体珊瑚共同繁育 ,种属分异度高 ,且地方性种数量大 ,表现为热带 -亚热带生物区系的特点 ,说明华北板块晚石炭世古地理位置应位于古赤道附近的热带 -亚热带 ,为古特提斯洋中的古板块之一     

长刺泡沫状珊瑚(Gyalophylloides Cao 1975)属骨骼微细构造的电镜研究

Gyalophylloides Cao 1975属的电镜研究表明,其骨骼构造以方解石晶片组成的层状骨骼为主,它形成壁部构造和横列构造,在隔壁之间充填联结,在隔壁内包绕隔壁刺,在隔壁刺内联结和包绕杆状体。本属纤状骨骼的组成单元是晶粒和短轴晶柱,它们只见于杆状体轴部。文中还描述了本属的两个新种。     

Homalophyllum属的个体演化及其骨骼微细构造的电镜研究

本文通过对采自内蒙古下泥盆统珠斯楞组的Homalophyllum属的系列切片及电镜研究表明:（1）其个体发育早期,主隔壁细长,无中轴,至晚期,上隔壁变短,一级隔壁在轴部膨大形成明显的中轴。（2）骨胳构造以纤状骨骼为主,呈扇状排列,规则完整的晶榍构成隔壁构造。其基本组成单元为向上逐渐展宽的桨状晶条。本属的层状骨骼为方解石晶片,只见于外壁部分。笔者对Homalophyllum colmniferum（新种）也作了描述。     

四射珊瑚AuloPhyllum fungites骨骼微细构造的电镜研究

本文对Aulophyllum fungires （Fleming）,1828的骨骼微细构造进行了扫描电镜研究.结果表明,其骨骼纵列构造和横列构造全由纤状骨骼方解石晶针构成.晶针大小可分两级:大者在隔壁和横板中,大小近相等,其平均长度为32μm,平均直径为4μm;小者在鳞板,内斜板和柱隔壁中,其平均长度为10μm,平均直径2μm.晶针只在隔壁中沿轴部组成一排晶（?）,其平均直径为30—60μm,晶（?）两侧晶针组成晶束几近垂直,并间歇生长.在纵切面上,横板与隔壁相接处,间歇生长线是连续的,说明两者同步增长和形成过程相同.     

EARLY CARBONIFEROUS RUGOSA IN YANFANG OF QUJING DISTRICT,YUNNAN

：Yumushan block on the north margin of Qilian mountain, with Jiudong basin and Minle basin to the west and east respectively, belongs to the fore-land depression in NNW direction at the north margin of the Qilian mountain fold belt. The Yumushan block has been thought of as a fault-uplift, which separates the two basins formed during late Yanshanian orogeny. However, the recognition of fault zones at the western margin of the Yumushan block, and the tectonic and sedimentary analyses of the Yumushan block and the basins, cast doubts to the tectonic property of the block. It is suggested that the two basins be derived from an united large basin at least during Mesozoic and the Yumushan block be nappe sheet formed due to NE imbricate thrusting on the north margin fault zone of the Qilian mountain. This proposal would provide valuable clues to further exploration of oil-gas and water resources in Hexi corridor basin belt.