No evidence for an afrotherian-like delayed dental eruption in South American notoungulates
No evidence for an afrotherian-like delayed dental eruption in South American notoungulates
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DOI：
10.1007/s00114-011-0795-y
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发表时间：
2011-06-01
影响因子：
--
通讯作者：
Martin, Thomas
中科院分区：
文献类型：
--
作者：
Billet, Guillaume;Martin, Thomas
南美洲有蹄类动物化石是非常感兴趣的相对于新的系统发育框架阐述了生活胎盘哺乳动物。特别是，对这些地方性分类群的研究可以测试南部胎盘系统发育与板块构造之间的一致性，超出了基于现存非洲兽目和异Arthrans的Atlantogenata假说中已经提出的观点。牙齿萌出相对于头骨生长延迟是现存非洲兽的特征之一，也可能是外节兽的特征。先前曾提到南美洲无蹄动物的牙齿晚期萌出，因此认为它们可能与非洲兽目动物相似，也可能与外节兽类相似。我们在这里提供了一个详细的研究牙齿萌出模式相对于头骨生长的无蹄动物。与以前的声明相反，我们的研究结果表明，目前没有证据表明这组中存在非洲兽样延迟性牙萌出。目前，推断无蹄动物没有延迟的牙齿萌出并不支持无蹄动物与寰齿/非洲兽的亲缘关系，但其他寰齿/非洲兽的特征仍有待于在这个群体和其他南美有蹄类动物中进行更详细的探索。
The fossil South American ungulates are of great interest relative to the new phylogenetic framework elaborated for living placental mammals. In particular, studies on these endemic taxa can allow for testing congruence between southern placental phylogeny and plate tectonics, beyond what has already been suggested in the Atlantogenata hypothesis based on extant afrotherians and xenarthrans. The presence of delayed dental eruption relative to skull growth is one feature characterizing the extant afrotherians and possibly the xenarthrans. Late dental eruption has been mentioned previously in South American notoungulates, thus suggesting possible resemblance with afrotherians and perhaps xenarthrans. We provide here a detailed study of the dental eruption pattern relative to the skull growth in the notoungulates. In contrast to previous statements, our results demonstrate that there is currently no evidence for an afrotherian-like delayed dental eruption in this group. For now, the inferred absence of a delayed dental eruption in notoungulates does not support atlantogenatan/afrotherian affinities for the Notoungulata, but other atlantogenatan/afrotherian characteristics remain to be explored in more detail in this group and other South American ungulates.