• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Geosciences >Homology and Potential Cellular and Molecular Mechanisms for the Development of Unique Feather Morphologies in Early Birds
【24h】

Homology and Potential Cellular and Molecular Mechanisms for the Development of Unique Feather Morphologies in Early Birds

机译：同源和潜在的细胞和分子机制，发展早期鸟类的独特羽毛形态。

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

At least two lineages of Mesozoic birds are known to have possessed a distinct feather morphotype for which there is no neornithine (modern) equivalent. The early stepwise evolution of apparently modern feathers occurred within Maniraptora, basal to the avian transition, with asymmetrical pennaceous feathers suited for flight present in the most basal recognized avian, Archaeopteryx lithographica. The number of extinct primitive feather morphotypes recognized among non-avian dinosaurs continues to increase with new discoveries; some of these resemble feathers present in basal birds. As a result, feathers between phylogenetically widely separated taxa have been described as homologous. Here we examine the extinct feather morphotypes recognized within Aves and compare these structures with those found in non-avian dinosaurs. We conclude that the “rachis dominated” tail feathers of Confuciusornis sanctus and some enantiornithines are not equivalent to the “proximally ribbon-like” pennaceous feathers of the juvenile oviraptorosaur Similicaudipteryx yixianensis. Close morphological analysis of these unusual rectrices in basal birds supports the interpretation that they are modified pennaceous feathers. Because this feather morphotype is not seen in living birds, we build on current understanding of modern feather molecular morphogenesis to suggest a hypothetical molecular developmental model for the formation of the rachis dominated feathers of extinct basal birds.
机译：已知至少有两个中生代鸟类具有独特的羽毛形态型，而没有相应的新鸟氨酸（现代）。显然现代羽毛的早期逐步进化发生在Maniraptora内，以鸟类过渡为基础，在最基础的公认鸟类始祖鸟石版印刷中出现了不对称的针状羽毛，适合飞行。随着新发现的出现，在非禽类恐龙中被识别的绝种原始羽毛形态类型的数量继续增加。其中一些类似于基础鸟类中存在的羽毛。结果，在系统发育上广泛分离的分类单元之间的羽毛被描述为同源的。在这里，我们检查了Aves内公认的绝种羽毛形态，并将这些结构与非禽类恐龙中的结构进行了比较。我们得出的结论是，孔雀草和一些对映鸟氨酸的“根茎占主导地位”的尾羽不等同于少年无齿龙类拟南芥的“近似带状”针状羽。对基础鸟类中这些异常直肠的紧密形态学分析表明，它们是变种的羽状羽毛。因为这种羽毛形态在活禽中没有出现，所以我们以对现代羽毛分子形态发生的当前理解为基础，提出了一种假设的分子发育模型，用于形成已灭绝的基础鸟的以拉奇人为主的羽毛。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号