PRIMITIVE FOSSIL RODENT FROM INNER-MONGOLIA AND ITS IMPLICATIONS FOR MAMMALIAN PHYLOGENY
PRIMITIVE FOSSIL RODENT FROM INNER-MONGOLIA AND ITS IMPLICATIONS FOR MAMMALIAN PHYLOGENY
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DOI：
10.1038/370134a0
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发表时间：
1994-07-14
期刊：
影响因子：
64.8
通讯作者：
ZHAI, RJ
中科院分区：
文献类型：
--
作者：
MENG, J;WYSS, AR;ZHAI, RJ
啮齿类动物的进化起源被最晚古新世的化石记录（1，2）中的啮齿类动物的突然和高度转变所掩盖。本文报道了在中国内蒙古古新世-始新世过渡期地层中发现的一种新的原始啮齿动物的牙齿化石。这一分类群的惊人保守的形态特征，Tribosphenomys minutus，gen. et sp. nov.，这一发现大大改变了以前关于祖先啮齿动物形态型的想法，这反过来又对理解啮齿动物的起源及其与其他真兽目哺乳动物的关系具有重要意义。这个新化石，结合最近的形态学（3）和分子（4，5）证据证实啮齿动物单系，表明需要重新评估gliriform eutherians之间的系统发育亲和力。我们的研究结果表明，姐妹组的新分类群的位置，其他啮齿动物，并支持联盟的兔（兔）和啮齿动物（队列格利尔斯）。它们还表明了一个已灭绝的组合，“Eurymylidae”的paraphyly，并揭示了一个出乎意料的复杂模式的性格进化的祖先附近的啮齿动物。
THE evolutionary origin of rodents is obscured by the group's sudden and highly transformed first appearance in the fossil record(1,2) in the latest Paleocene. We report here the discovery of nearly complete dental remains of an extraordinary new primitive rodent from strata of transitional Paleocene-Eocene age in Inner Mongolia, China. The strikingly conservative morphological features of this taxon, Tribosphenomys minutus, gen. et sp. nov., substantially modify previous ideas about the ancestral rodent morphotype, which in turn has important implications for understanding the origin of rodents and their relationship to other eutherian mammals. This new fossil, in conjunction with recent morphological(3) and molecular(4,5) evidence confirming rodent monophyly, indicates the need for a reassessment of phylogenetic affinities among gliriform eutherians. Our results indicate a sister-group position of the new taxon to other rodents, and support the alliance of lagomorphs (rabbits) and rodents (cohort Glires). They also suggest the paraphyly of an extinct assemblage, the 'Eurymylidae', and reveal an unexpectedly complex pattern of character evolution near the ancestry of Rodentia.