...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >Paleocene emergence of elephant relatives and the rapid radiation of African ungulates
【24h】

Paleocene emergence of elephant relatives and the rapid radiation of African ungulates

机译：大象亲属的古新世出现和非洲有蹄类动物的迅速辐射

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

Elephants are the only living representatives of the Proboscidea, a formerly diverse mammalian order whose history began with the 55-million years (mys) old Phosphatherium. Reported here is the discovery from the early late Paleocene of Morocco, ca. 60 mys, of the oldest and most primitive elephant relative, Eritherium azzou-zorum n.g., n.sp., which is one of the earliest known representatives of modern placental orders. This well supported stem proboscidean is extraordinarily primitive and condylarth-like. It provides the first dental evidence of a resemblance between the proboscideans and African ungulates (paenungulates) on the one hand and the louisinines and early macroscelideans on the other. Eritherium illustrates the origin of the elephant order at a previously unknown primitive stage among paenungulates and "ungulates." The primitive morphology of Eritherium suggests a recent and rapid paenungulate radiation after the Cretaceous-Tertiary boundary, probably favoured by early endemic African paleoeco-systems. At a broader scale, Eritherium provides a new old calibration point of the placental tree and supports an explosive placental radiation. The Ouled Abdoun basin, which yields the oldest known African placentals, is a key locality for elucidating phylogeny and early evolution of paenungulates and other related endemic African lineages.
机译：象是长鼻象（Proboscidea）的唯一活体代表。长鼻象是一种以前的哺乳动物秩序，其历史始于5500万年前的磷鳞藻。这里报道的是大约从摩洛哥古新世晚期开始的发现。距今60岁的最古老，最原始的大象亲戚Eritherium azzou-zorum n.g.，n.sp.是现代胎盘秩序的最早代表之一。这种支撑良好的茎状前生动物非常原始，且类似于con突。它提供了第一个牙科证据，一方面是长喙类动物和非洲有蹄类动物（paenungulates）之间的相似，另一方面是路易斯安那州和早期大型食蟹类之间的相似性。 Eritherium说明了在象皮动物和“有蹄类动物”中先前未知的原始阶段大象的起源。 Eritherium的原始形态表明，在白垩纪-第三纪边界之后出现了近期且快速的齿状辐射，这可能是早期地方性非洲古生物系统所青睐的。在更广泛的规模上，Eritherium提供了胎盘树的新旧校准点并支持爆炸性胎盘辐射。 Ouled Abdoun盆地是已知最古老的非洲胎盘，是阐明棘突及其他相关非洲特有血统的系统发育和早期进化的重要场所。

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