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221.
222.
《Palaeoworld》2014,23(2):125-142
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. 相似文献
223.
Two new species of Mongolbittacus Petrulevičius, Huang & Ren, 2007, Mongolbittacus
speciosus
sp. n. and Mongolbittacus
oligophlebius
sp. n., and two new species of Exilibittacus Yang, Ren & Shih, 2012, Exilibittacus
foliaceus
sp. n. and Exilibittacus
plagioneurus
sp. n., in the family Bittacidae, are described and illustrated based on five well-preserved fossil specimens. These specimens were collected from the late Middle Jurassic Jiulongshan Formation of Daohugou, Inner Mongolia, China. These new findings enhance our understanding of the morphological characters of early hangingflies and highlight the diversity of bittacids in the Mid Mesozoic ecosystems. 相似文献
224.
Antony A. Boucard Stephan Maxeiner Thomas C. Südhof 《The Journal of biological chemistry》2014,289(1):387-402
Latrophilin-1, -2, and -3 are adhesion-type G protein-coupled receptors that are auxiliary α-latrotoxin receptors, suggesting that they may have a synaptic function. Using pulldowns, we here identify teneurins, type II transmembrane proteins that are also candidate synaptic cell-adhesion molecules, as interactors for the lectin-like domain of latrophilins. We show that teneurin binds to latrophilins with nanomolar affinity and that this binding mediates cell adhesion, consistent with a role of teneurin binding to latrophilins in trans-synaptic interactions. All latrophilins are subject to alternative splicing at an N-terminal site; in latrophilin-1, this alternative splicing modulates teneurin binding but has no effect on binding of latrophilin-1 to another ligand, FLRT3. Addition to cultured neurons of soluble teneurin-binding fragments of latrophilin-1 decreased synapse density, suggesting that latrophilin binding to teneurin may directly or indirectly influence synapse formation and/or maintenance. These observations are potentially intriguing in view of the proposed role for Drosophila teneurins in determining synapse specificity. However, teneurins in Drosophila were suggested to act as homophilic cell-adhesion molecules, whereas our findings suggest a heterophilic interaction mechanism. Thus, we tested whether mammalian teneurins also are homophilic cell-adhesion molecules, in addition to binding to latrophilins as heterophilic cell-adhesion molecules. Strikingly, we find that although teneurins bind to each other in solution, homophilic teneurin-teneurin binding is unable to support stable cell adhesion, different from heterophilic teneurin-latrophilin binding. Thus, mammalian teneurins act as heterophilic cell-adhesion molecules that may be involved in trans-neuronal interaction processes such as synapse formation or maintenance. 相似文献
225.
Yan Liang Renbin Zhan Jisuo Jin 《Lethaia: An International Journal of Palaeontology and Stratigraphy》2014,47(3):432-436
The oldest Foliomena fauna was, until now, known from the middle–upper Miaopo Formation (Nemagraptus gracilis Biozone, lower Sandbian, basal Upper Ordovician) of South China. In this study, the oldest record of the fauna is set back to the latest Darriwilian (upper Hustedograptus teretiusculus Biozone), represented by Foliomena jielingensis and some typical constituents of the Foliomena fauna from the basal Miaopo Formation at Jieling, northern Yichang, western Hubei Province, central China. The Miaopo Formation is characterized by its organic‐rich dark‐grey shale facies, unique in its localized distribution on the Yangtze Platform, and distinguished by its rich and diverse benthic and graptolitic faunas. This suggests an origin of the Foliomena fauna in periodically oxygen‐starved local depressions on the Yangtze Platform during the Middle–Late Ordovician transition. 相似文献
226.
The Earliest Normal Flower from Liaoning Province, China 总被引:1,自引:0,他引:1
The early evolution of angiosperms has been a focus of intensive research for more than a century. The Yixian Formation in western Liaoning yields one of the earliest angiosperm macrofloras. Despite multitudes of angiosperm fossils uncovered, including Archaefructus and Sinocarpus , no bona fide normal flower has been dated to 125 Ma (mega-annum) or older. Here we report Callianthus dilae gen. et sp. nov. from the Yixian Formation (Early Cretaceous) in western Liaoning, China as the earliest normal flower known to date. The flower demonstrates a typical floral organization, including tepals, androecium, and gynoecium. The tepals are spatulate with parallel veins. The stamens have a slender filament, a globular anther, bristles at the anther apex, and in situ round-triangular pollen grains. The gynoecium is composed of two stylate carpels enclosed in a fleshy envelope, and develops into a "hip" when mature. Since the well-accepted history of angiosperms is not much longer than 125 Ma, Callianthus together with Chaoyangia, Archaefructus and Sinocarpus from the Yixian Formation demonstrate a surprisingly high diversity of angiosperms, implying a history of angiosperms much longer than currently accepted. 相似文献
227.
228.
福建武平中二叠统童子岩组的小有孔虫 总被引:10,自引:5,他引:5
本文首次报道福建武平地区中二叠统童子岩组中与复通道Tin(Polydiexodina)群共生的小有孔虫动物群18属44种,其中新种3个,该动物群在国内很少报道。通过这一小有孔虫群的研究,为童子岩组的地层时代时属提供了又一佐证,对该地区童子岩组中的炭岩层古生态特征也作了简单的讨论。 相似文献
229.
通过对新疆克拉玛依地区吐孜阿克内沟剖面三工河组孢粉组合的研究,共鉴定孢粉23属32种,藻类化石2属4种,命名为Disacciatrileti-Monocolpates-Cyathidites组合(简称DMC组合)。描述了5种花粉Abietineaepollenites dunrobinensis Couper,Pseudopicea monstruosa Bolch.,Podocarpidites 相似文献
230.