首页> 外文期刊>Quaternary International >Mammoths and mylodonts: Exotic species from two different continents in North American Pleistocene faunas
【24h】

Mammoths and mylodonts: Exotic species from two different continents in North American Pleistocene faunas

机译:猛mm象和黑齿象:来自北美更新世动物群的两个不同大陆的外来物种

获取原文
获取原文并翻译 | 示例
       

摘要

Throughout the Cenozoic, the North American mammalian fauna has been enriched by the appearance of new taxa originating on different continents. During most of the Tertiary, the primary source area of these new taxa was Eurasia with dispersal across some version of the Bering Land Bridge. In the late Pliocene (Blancan) ca. 2.5 mya, the creation of the Panamanian Land Bridge permitted the northward dispersal of species of South American origin including ground sloths. One of these sloths was "Glossotherium" chapadmalense, which in turn gave rise to the Pleistocene species Paramylodon harlani. Mammoths first appear in North America at the beginning of the Irvingtonian ca. 1.9 mya. Despite originating on two different continents, the two species are often found together in North American Pleistocene faunas and shared a common habitat. Both of these lineages are commonly interpreted as grazers, indicative of open grassland habitat, and both of these exotic species shared this habitat with North American endemic species such as horses, also interpreted as grazers. Despite their association in North American faunas, mammoths did not disperse into South America and mylodont sloths were unable to disperse into Eurasia. This suggests there were some aspects of their ecology they did not have in common and there existed a limited zone of conditions that permitted them to share common habitat. There is no evidence that the appearance of either species in North America resulted'in the extinction of any native species. The question is how these different species, immigrants and endemics, were able to avoid competition, coexist, and become integrated into a single fauna, thus enriching the overall North American Pleistocene fauna.
机译:在整个新生代,北美哺乳动物区系因起源于不同大陆的新生物群的出现而变得更加丰富。在第三纪的大部分时间里,这些新分类单元的主要来源地区是欧亚大陆,并散布在某些版本的白令陆桥上。在上新世(Blancan)晚期。 2.5 mya,巴拿马陆桥的创建使南美洲起源物种(包括地面树懒)向北扩散。这些树懒之一是“ Glossotherium” chapadmalense,它继而产生了更新世的物种Paramylodon harlani。猛mm象最早出现在北美的伊尔文顿时期。 1.9妙。尽管起源于两个不同的大陆,但这两个物种通常在北美更新世动物区系中一起发现,并具有共同的栖息地。这两个血统通常被解释为放牧者,表明草地是开放的栖息地,并且这两个外来物种都与北美特有物种(例如马)也共享该生境,例如马。尽管猛in象与北美动物区系有联系,但它们并没有散布到南美,而mylodont树懒也无法散布到欧亚大陆。这表明他们在生态学方面没有某些共同之处,并且存在有限的条件区域,使他们可以共享共同的栖息地。没有证据表明北美任何一种物种的出现都会导致任何本土物种的灭绝。问题是这些不同的物种(移民和特有物种)如何能够避免竞争,共存并融入一个单一的动物区系,从而丰富了整个北美更新世的动物区系。

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