Extreme insular dwarfism evolved in a mammoth.
Extreme insular dwarfism evolved in a mammoth.
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猛犸象进化出了极端的岛状侏儒症。
DOI：
10.1098/rspb.2012.0671
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Herridge VL
中科院分区：
文献类型：
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作者：
Herridge VL
在更新世大象中看到的孤岛侏儒症已经成为岛国规则的缩影；然而，我们对这一现象的理解受到了糟糕的分类学的阻碍。地中海矮象是观察到最极端的岛状矮小症病例的地方，一个关键的系统问题仍然没有解决：是否所有的类群都是同一大陆物种的类群侏儒--古长牙象(直齿象)，还是有些与猛犸象有关？古老的DNA和地质年代学证据已经被用来支持克雷坦岛古龙牙科动物起源于哺乳动物，但这些研究被证明是有缺陷的。根据现有的收藏品和最近的野外发现，我们提出了新的形态证据，证明了‘P’的分类地位。Creticus，并表明它确实是一种猛犸象，很可能来自于早更新世Mammutus meridionalisis或晚上更新世Mammutus rumanus。我们还发现，克氏猛犸象比其他已知的岛状矮小猛犸象要小，在大小上与西西里和马耳他的最小矮小的古猛犸象物种相似，使其成为已知的最小的猛犸象物种。这些发现表明，极端岛状侏儒症在两个大象谱系中独立进化到了类似的程度。
The insular dwarfism seen in Pleistocene elephants has come to epitomize the island rule; yet our understanding of this phenomenon is hampered by poor taxonomy. For Mediterranean dwarf elephants, where the most extreme cases of insular dwarfism are observed, a key systematic question remains unresolved: are all taxa phyletic dwarfs of a single mainland speciesPalaeoloxodon antiquus(straight-tusked elephant), or are some referable toMammuthus(mammoths)? Ancient DNA and geochronological evidence have been used to support aMammuthusorigin for the Cretan‘Palaeoloxodon’ creticus, but these studies have been shown to be flawed. On the basis of existing collections and recent field discoveries, we present new, morphological evidence for the taxonomic status of‘P’. creticus, and show that it is indeed a mammoth, most probably derived from Early PleistoceneMammuthus meridionalisor possibly Late PlioceneMammuthus rumanus. We also show thatMammuthus creticusis smaller than other known insular dwarf mammoths, and is similar in size to the smallest dwarfPalaeoloxodonspecies from Sicily and Malta, making it the smallest mammoth species known to have existed. These findings indicate that extreme insular dwarfism has evolved to a similar degree independently in two elephant lineages.