Thoracolumbar vertebral number:: the first skeletal synapomorphy for afrotherian mammals
Thoracolumbar vertebral number:: the first skeletal synapomorphy for afrotherian mammals
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DOI：
10.1017/s1477200006002258
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发表时间：
2007-03-01
影响因子：
1.9
通讯作者：
Kuratani, Shigeru
中科院分区：
文献类型：
--
作者：
Sanchez-Villagra, Marcelo R.;Narita, Yuichi;Kuratani, Shigeru
有压倒性的分子支持单系的一个超序数进化枝的生活非洲胎盘哺乳动物，Afrotheria，但没有一个明确的形态突触这组。我们进行了一项调查的胸腰椎脊椎动物的数量在哺乳动物，代表86个活的和12个化石物种的标本和解剖学文献的全面审查的基础上检查。共有19个胸腰椎是类形的哺乳动物，真兽目和后兽目。Metatherians显示没有变化，在这个plesiomorphic条件下，建议存在的发展限制，在对比的变化，同样古老的真兽目分支。在胎盘发育的过程中，有几种与近形条件不同的情况独立地发展出来。基于分子序列数据的已发表的系统发育框架上的信息的优化揭示了胸腰椎椎骨数量的增加是非洲兽的第一个明确的骨骼突触形态。
There is overwhelming molecular support for the monophyly of a supra-ordinal clade of living African placental mammals, the Afrotheria, but there is not a single unequivocal morphological synapomorphy for this group. We conducted a survey of thoraco-lumbar vertebral numbers across mammals, based on the examination of specimens representing 86 living and 12 fossil species and a thorough review of the anatomical literature. A total of 19 thoraco-lumbar vertebrae is plesiomorphic for mammals, eutherians and metatherians. Metatherians show no variation in this plesiomorphic condition, suggesting the presence of a developmental constraint, in view of the contrasting variability of the equally old eutherian clade. Several deviations from the plesiomorphic condition have evolved independently in the course of placental phylogeny. Optimization of the information on a published phylogenetic framework based on molecular sequence data reveals that an increase in the number of thoracolumbar vertebrae is the first unambiguous skeletal synapomorphy of Afrotheria.