bob正常玩会被黑吗

联系我们 | 网站地图 | |
首页 概况简介 机构设置 科研装备 科研成果 招聘招生 信息公开 国际交流 学术出版物 党建文化
科学传播
科学新闻
科研进展
科普动态
媒体扫描
电子杂志-FOSSIL@NET
科普站点-化石网网站群
科普场馆-古生物博物馆
科普期刊-生物进化
精彩专题
化石图片
科学视频
通知公告
新冠肺炎疫情防控专题
关于组织开展“科学梦...
bob正常玩会被黑吗2020年拟...
相关链接


现在位置:首页 > 科学传播 > 媒体扫描
 
【EurekAlert】Jurassic fossils from northeastern China reveal morphological stasis in the catkin-yew
2020-07-17 | 编辑: | 【

2020.7.11 From EurekAlert  

  The Taxaceae are a distinct conifer family widely used in ornamental horticulture and are an important source of chemotherapeutic drugs (e.g., Paclitaxel). Fossil evidence of Taxaceae is based mainly on isolated leaves or leafy shoots for which the reproductive structures are unknown. However, several more complete fossils with attached seed-bearing structures show that Taxaceae had diverged from other conifers by the earliest Jurassic and were probably diverse during the Jurassic and Cretaceous.

  Dong and colleagues add to knowledge of early Taxaceae based on well-preserved fossils from the Middle-Late Jurassic (~160 Myr) Daohugou Bed in eastern Inner Mongolia, northeastern China. The material includes the terminal portion of a leafy shoot with attached seed-bearing structures, and a leafy shoot with two-orders of branching in which each ultimate shoot has a terminal conical bud. The fossil leafy shoots have opposite and decussate leaves. Attached seed-bearing structures arise singly from the axil of a normal vegetative leaf and consist of a short, naked axis bearing a single terminal seed that is enclosed by pairs of opposite and decussate bracts.

  These fossils bear a striking resemblance to the leafy shoots and seed-bearing structures of extant catkin-yews Amentotaxus and only differ in having shorter seed-bearing axes. Assignment of the fossils to the living genus is also supported by cladistic analyses based on morphological characters of living and fossil Taxaceae. These fossils are among the most completely known of all fossil Taxaceae. Extant catkin-yews are endangered and have very restricted distributions in Eastern Asia. The Daohugou fossils document that among the diverse extinct Mesozoic Taxaceae were ancient catkin-yews. Like Ginkgo biloba, the catkin-yews are living fossils that have undergone little morphological change since the Middle-Late Jurassic.


(a, b) cf. Amentotaxus from the Middle-Late Jurassic Daoguhou Bed in eastern Inner Mongolia, China. (c) Living A. yunnanensis. (d) Living A. argotaenia. (e) Reconstructive drawing of specimen in (a). (f) Line drawing of the two-order leafy shoot in (b).

###

  

See the article:

  Dong C., Shi G., Herrera F., Wang Y., Herendeen P.S., Crane P.R., 2020. Middle-Late Jurassic fossils from northeastern China reveal morphological stasis in the catkin-yew. National Science Review, nwaa138. DOI: 10.1093/nsr/nwaa138

  Link:








 
  相关新闻
Copyright 2009 bob正常玩会被黑吗
地址:南京市北京东路39号(210008) Tel:025-83282105 Fax:025-83357026 Email:ngb@nigpas.ac.cn 微信公众号:NIGPAS(中科院南古所)
苏公网安备32010202010359号