• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Systematic Palaeontology >Awamokoa tokarahi, a new basal dolphin in the Platanistoidea (late Oligocene, New Zealand)
【24h】

Awamokoa tokarahi, a new basal dolphin in the Platanistoidea (late Oligocene, New Zealand)

机译：Platanistoidea（新世晚期，新西兰）中的单个基底海豚

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A late Oligocene marine dolphin - Awamokoa tokarahi gen. et sp. nov. - from the Kokoamu Greensand (Duntroonian stage, 25.2-27.3 Ma) of Tokarahi, North Otago, New Zealand, is a representative of the clade Platanistoidea. The single known specimen preserves a fragmentary skull, well-preserved tympanoperiotics (ear bones) and several postcranial elements. The fossil helps to trace platanistoid history from its oceanic origins to the endangered living South Asian river dolphins. The morphologies of the temporal fossa and mandible suggest that Awamokoa and other more basal platanistoids (Waipatia) were probably macroraptorial feeders with a strong bite. In contrast, later-diverging fossil platanistoids {Huaridelphis + Squalodelphis + Zarhachis) and the modem Platanista gangetica, which display longer rostra and increased numbers of nearly homodont teeth, probably had/has a faster but weaker bite, with less processing of food than the basal platanistoids. Otekaikea and Notocetus show intermediate jaw structure. Long-term shape changes in the periotic (earbone) involve the pars cochlearis (thinner in later taxa) and changes in vascular sulci (less pronounced in later taxa), but the exact functional significance is uncertain.
机译：渐新世晚期的海豚-Awamokoa tokarahi gen。等。十一月-来自新西兰北奥塔哥Tokarahi的Kokoamu Greensand（Duntroonian阶段，25.2-27.3 Ma）是Platanistoidea进化枝的代表。单个已知的标本保存着一块颅骨碎片，保存完好的鼓膜手术（耳骨）和一些颅后元件。该化石有助于追溯从海洋起源到濒临灭绝的南亚河豚的历史。颞窝和下颌骨的形态表明，Awamokoa和其他更多的基底平台动物（Waipatia）可能是叮咬很强的大型巨嘴动物。相反，较晚散发的化石类扁担动物（Huaridelphis + Squalodelphis + Zarhachis）和现代的Platanista gangetica，表现出更长的角叉网和增加的近乎牙齿的齿数，咬/咬的速度可能更快，但强度较弱，对食物的加工少于基底类扁桃体。 Otekaikea和Notocetus表现出中等的颌骨结构。骨膜的长期形状变化（耳骨）涉及耳蜗（在后面的分类单元中变薄）和血管沟的变化（在后面的分类单元中不明显），但是确切的功能意义尚不确定。

著录项

  • 来源
    《Journal of Systematic Palaeontology》 |2017年第8期|365-386|共22页
  • 作者

    Yoshihiro Tanaka; R. Ewan Fordyce;

  • 作者单位

    Department of Geology, University of Otago, PO Box 56, Dunedin 9054, New Zealand,Numata Fossil Museum, 2-7-49, Minami 1, Numata town, Hokkaido, 078-2225 Japan,Hokkaido University Museum, Kita 10, Nishi 8, Kita-ku, Sapporo, Hokkaido, 060-0810 Japan;

    Department of Geology, University of Otago, PO Box 56, Dunedin 9054, New Zealand,Departments of Paleobiology and Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington DC, USA;

  • 收录信息
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

    Odontoceti; systematics; morphology; skeleton; evolution;

    机译：Odontoceti;系统的形态学;骨架;演化;

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