首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   23篇
  免费   1篇
  2022年   1篇
  2020年   2篇
  2019年   3篇
  2017年   1篇
  2016年   1篇
  2015年   1篇
  2008年   2篇
  2006年   3篇
  2005年   1篇
  2004年   2篇
  2003年   3篇
  2001年   1篇
  1999年   1篇
  1996年   1篇
  1981年   1篇
排序方式: 共有24条查询结果,搜索用时 781 毫秒
21.
The Upper Triassic tetrapod fossil record of North America features a pronounced discrepancy between the assemblages of present-day Virginia and North Carolina relative to those of the American Southwest. While both are typified by large-bodied archosaurian reptiles like phytosaurs and aetosaurs, the latter notably lacks substantial representation of mammal relatives, including cynodonts. Recently collected non-mammalian eucynodontian jaws from the middle Norian Blue Mesa Member of the Chinle Formation in northeastern Arizona shed light on the Triassic cynodont record from western equatorial Pangaea. Importantly, they reveal new biogeographic connections to eastern equatorial Pangaea as well as southern portions of the supercontinent. This discovery indicates that the faunal dissimilarity previously recognized between the western and eastern portions of equatorial Pangaea is overstated and possibly reflects longstanding sampling biases, rather than a true biogeographic pattern.  相似文献   
22.
The Wachholz site (Caturrita Formation, Late Triassic), in Agudo, Rio Grande do Sul (RS), southern Brazil, has yielded several sauropodomorphs. This includes CAPPA/UFSM 0002, described here based on associated elements from the basalmost portion of the site. The specimen possesses a set of traits shared with typical ‘prosauropods’: a concave caudal margin of the trunk neural spines and a broadly convex proximal end of metacarpal V. However, it also retains some plesiomorphic features, for instance, the slender pedal digit I. Some bones closely resemble those of Unaysaurus tolentinoi, the other definitive sauropodomorph from the Caturrita Formation, an affinity corroborated by a new phylogenetic analysis. An updated biostratigraphic framework correlates the Wachholz, Água Negra (São Martinho da Serra/RS) and Botucaraí Hill (Candelária/RS) sites based on their sample of sauropodomorphs. In addition, the record of Jachaleria in the Botucaraí Hill site, a dicynodont also known from early Norian deposits of Argentina, indicates an equivalent age to deposits bearing U. tolentioni. Accordingly, a more constrained age is proposed for the Água Negra site. This is important as the early Norian marks the transition from an epoch of low sauropodomorphs representativeness to a period of extreme abundance of the group in Early-to-Middle Mesozoic ecosystems.  相似文献   
23.
Invertebrate Anisian and Norian reef boulders were found in the Gerence and Güvercinlik Formations, respectively, exposed in northeastern part of the Karaburun Peninsula, western Turkey. Halimedacean green algae and solenoporacean red algae, usually associated with other reef building organisms are described in this paper. The following taxa were determinated: halimedaceans: Egericodium hungaricum Flügel, Velledits, Senowbari-Daryan and Riedel, Aternasus irregularis n. gen., n. sp.; solenoporaceans: Solenopora cf. alcicornis Ott, Solenopora triasina Vinassa de Regny, Solenopora vachardi n. sp., Solenopora concentrica n. sp., Solenopora paraconcentrica n. sp., Tauristorea parallela Senowbari-Daryan and Link, Tauristorea discursa n. sp., and Parachaetetes cassianus (Flügel). The monospecific genus Aternasus n. gen. is the most abundant alga within the Anisian reef boulders. The solenoporaceans are represented by several taxa but the individual species are less abundant. E. hungaricum, T. parallela Senowbari-Daryan and Link, and S. triasina Vinassa de Regny are described from the Norian reef limestones embedded in Güvercinlik Formation, all other taxa from the Anisian reef boulders embedded in the Gerence Formation.  相似文献   
24.
Two colonial serpulid worm tubes—Filograna taurica n. sp. and Filograna serialis n. sp.—from the Upper Triassic (Norian) reef boulders occurring in Taurus Mts. (south Turkey) are described. As bafflers, both species of Filograna build microbioherms reaching dimensions of up to 15 cm. Both species were not known either in Turkey or in any other Triassic localities of the Tethyan realm.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号