依据牙形刺确定的蒙古国塔琳波格德组（Taliin Bogd Formation）的时代

在蒙古南部波尔海尔汗乌尔(Bor hairhan uul)剖面的塔琳波格德组下部的6个样品中发现了牙形刺,通过研究清楚地表明含牙形刺动物群的塔琳波格德组下部的时代是中洛霍考夫阶(早泥盆世)到中艾菲尔阶(中泥盆世).塔琳波格德组的牙形刺动物群更接近于北美同时期的动物群,而与欧洲同期动物群相远.这一动物群可能属于冷水动物群.作者在文中描写了一个新种:Steptotaxis mongolianus sp.nov.Wang.     

Bacterial epibionts and endolichenic actinobacteria and fungi in the Lower Devonian lichen Chlorolichenomycites salopensis

The charcoalified fragment of the dorsiventrally organized, internally stratified presumed green algal lichen Chlorolichenomycites salopensis from the Lower Devonian Lochkovian strata in the Welsh Borderland carries bacterial colonies on the upper surface, i.e. the cortex, and actinobacterial filaments in the medulla underneath the photobiont layer. Moreover relatively thin hyphae of presumed endolichenic fungi were found. As in extant lichens, which are best regarded as consortia with an unknown number of participants, this internally stratified, fossil thallus fragment of a presumed green algal lichen harbours a diverse microbial community.     

Contributions to the diversity in cryptogamic covers in the mid‐Palaeozoic: Nematothallus revisited

Compression fossils from the Silurian and Devonian of southern Britain, composed of cuticles and tubes, were described by W. H. Lang as the genus Nematothallus and placed, with Prototaxites, in Nematophytales, related neither to algae nor tracheophytes. Dispersed cuticles of Nematothallus and perforated forms assigned to Cosmochlaina were frequently recovered in macerates, their affinities being unresolved. New collections from a Lochkovian locality in the Welsh Borderland permitted the reconstruction of the stratified thalli of these nematophytes; they comprise a superficial cortex (which produced the cuticles) overlying a palisade zone composed of septate, parallel tubes, presumed to be hyphae, and a basal zone comprising wefts of randomly interwoven hyphae. Excellent three dimensional preservation allows the erection of a new species of Nematothallus, N. williamii. A similar anatomy is seen in a new group of fossils with either circular incisions in the cortex or complete separation of thickened cortical cells, presumably comprising a developmental sequence. By their stratified organization the nematophytes differ from extant and extinct algae and bryophytes and the enigmatic Spongiophyton. A complex anatomy and septate tubes suggest affinity with lichenized fungi. Limited data support a fungal rather than embryophyte chemistry, but a photobiont is missing. Nematophytes, globally widespread in cryptogamic covers from mid‐Ordovician times, added to the biodiversity in early terrestrial ecosystems and enhanced chemical weathering. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 173 , 505–534.     

云南早泥盆世西山村组华南鱼类的首次发现

记述了云南曲靖地区早泥盆世洛霍考夫期华南鱼类一新属———王冠鱼(Stephaspis gen.nov.)。新属发现于西山村组下部致密坚硬的石英砂岩中,其主要特征是:个体较大的华南鱼类,头甲呈长盾形,后缘向后凸出;角发育,侧向延伸,末端向头甲后侧方自然倾斜,内角不发育;具吻突,但不甚发育;中背孔较大,呈纵向椭圆形,前端稍尖,后端圆钝;眶孔较小,圆形,背位;头甲背面具一对背窗,呈狭长椭圆形,靠近头甲侧缘;感觉管系统不甚发育,仅见后眶上管、侧背管、侧横管及背联络管,后眶上管呈V字形;纹饰为细小的粒状瘤点。新属不仅是华南鱼类在西山村组的首次发现,也指示了目前华南鱼类出现的最低层位,为探讨华南鱼类的起源与早期辐射提供了重要资料。     

A new,high‐precision CA‐ID‐TIMS date for the ‘Kalkberg’ K‐bentonite (Judds Falls Bentonite)

The numerical calibration of the base of the Devonian is poorly constrained due to several factors. Few precise radioisotopic age determinations are available from the late Silurian and Early Devonian, and the limited published data carry large error bars from older analytical methodologies. Volcanic ashfalls suitable for dating occur in the Lower Devonian of the Appalachian Basin, but have not been precisely correlated into the global chronostratigraphical scheme because of limited bio‐ and lithostratigraphical information. Here, we report a new U‐Pb zircon radioisotopic age determination of 417.61 ± 0.12(0.23)[0.50] Ma and improved chronostratigraphical context, including revised biostratigraphy, for an ash bed in the New Scotland Formation, Helderberg Group, from the Lochkovian Stage that was previously identified as the Kalkberg K‐bentonite. This new information helps to integrate the classic New York Appalachian Basin succession into global Siluro‐Devonian stratigraphy, refine the calibration of the Silurian–Devonian boundary and more precisely estimate the duration of both time periods.     

Ontogeny of Ancyrodelloides carlsi (Boersma) and comments on its generic attribution (Conodonta,Lower Devonian)

The ontogeny of the Lochkovian conodont species Ancyrodelloides carlsi (Boersma) is demonstrated thanks to a rich population from Morocco. The studied sample includes elements at various growth stages from juvenile to gerontic. The data are confirmed by several elements in collections from several localities in the Carnic Alps (Italy and Austria). The absence of terraces at every stage of growth and the presence of a strong denticulated lateral process confirms the generic attribution of the species to genus Ancyrodelloides. Comments on the apparatus are provided. The geographical distribution of the species, limited to Europe and the Mediterranean region, challenges its stratigraphic value for long distance correlations.     

Palaeophytogeographical and palaeoecological implications of a miospore assemblage of earliest Devonian (Lochkovian) age from Saudi Arabia

Palynological samples from two boreholes drilled in the eastern part of Saudi Arabia contain a rich assemblage of cryptospores and trilete spores. They are dated as most probably Lochkovian in age. Intriguingly, the cryptospores are very similar to those from a coeval continental palynomorph assemblage from the Old Red Sandstone Continent, whereas the trilete spores show a strong affinity with miospore assemblages from Western Gondwana. It is suggested that cryptospore-producing plants inhabited confined, damp biotopes and had a wide range of climatic tolerance. On the other hand, trilete spore-producing plants inhabited a wider variety of biotopes but were more sensitive to climatic variations. The high degree of similarity between Old Red Sandstone and Saudi Arabian cryptospore assemblages favours palaeogeographic reconstructions where there is close proximity between Western Gondwana and Euramerica and/or a land connection between these palaeoplates. Climatic differences between the Old Red Sandstone Continent and the northern part of Western Gondwana can be invoked to explain the variations in the trilete spore assemblages.     

Early Devonian (Lochkovian) trilobites and brachiopods from the west Balkhash Region,Kazakhstan and their significance for regional terrane dynamics

A moderately diverse Early Devonian (Lochkovian) trilobite and brachiopod association has been recovered from the lower part of the volcano-sedimentary Shakshagaily Formation, exposed on the western side of Lake Balkhash in central Kazakhstan. Its discovery demonstrates the presence of Lower Devonian marine deposits in the region. The trilobite assemblage includes representatives of six genera: the dalmanitid Kasachstania alperovichi nov. sp. is the dominant taxon, with other components being Ananaspis?, Leonaspis?, Maurotarion, Trimerus (Edgillia), and Warburgella. Associated brachiopods include species of Glossoleptaena, Leptaena, Protolepstostrophia, Pseudostrophochonetes, and Resserella. Whilst a significant proportion of these taxa show distinct links with the contemporaneous trilobite and brachiopod faunas of the north Balkhash Region, the occurrence of Trimerus (Edgillia) aff. kinglakensis Gill, 1949 suggests a possible link with the Lochkovian trilobite fauna of the Australasian sector of Gondwana. The west Balkhash Region preserves an extensive record of late Silurian to Early Devonian island arc volcanism, slope-rise sedimentation and olistostrome formation, which has invariably been ignored in models favouring early amalgamation of the Kazakhstanian terranes into a single continent by the end of the Ordovician.