New light shed on the oldest insect
New light shed on the oldest insect
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DOI：
10.1038/nature02291
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发表时间：
2004-02-12
期刊：
影响因子：
64.8
通讯作者：
Grimaldi, DA
中科院分区：
文献类型：
--
作者：
Engel, MS;Grimaldi, DA
昆虫是所有生物中物种数量最多样化的谱系，从生态角度来说，它们在陆地生态系统中占主导地位。然而，动物的这种巨大辐射是如何以及何时产生的尚不清楚。只有少数化石可以让我们深入了解昆虫进化的最早阶段，其中包括来自苏格兰莱尼古红砂岩（布拉格；约 396-4.07 亿年前(1)）的燧石标本，该化石仅比最早的陆地动物群的地层稍微年轻一些。雷尼最著名的动物是跳尾虫 Rhyniella praecursor（Entognatha；跳虫），长期以来被认为是最古老的六足动物(2,3)。对于真正的昆虫（外颌类），最古老的记录是北美泥盆纪后期的两种明显无翅昆虫(4,5)。然而，我们在这里表明，Rhynie（Rhyniognatha hirsti）的化石碎片不仅是最早的真正昆虫，而且可能相对衍生于基部外颌动物。事实上，鼻颌目动物衍生出了与有翅昆虫相同的特征，这表明翅膀的起源可能比之前认为的更早。无论如何，鼻颌类表明昆虫起源于志留纪，并且是一些最早的陆地动物群的成员。
Insects are the most diverse lineage of all life in numbers of species, and ecologically they dominate terrestrial ecosystems. However, how and when this immense radiation of animals originated is unclear. Only a few fossils provide insight into the earliest stages of insect evolution, and among them are specimens in chert from Rhynie, Scotland's Old Red Sandstone (Pragian; about 396-407 million years ago(1)), which is only slightly younger than formations harbouring the earliest terrestrial faunas. The most well-known animal from Rhynie is the springtail Rhyniella praecursor (Entognatha; Collembola), long considered to be the oldest hexapod(2,3). For true insects (Ectognatha), the oldest records are two apparent wingless insects from later in the Devonian period of North America(4,5). Here we show, however, that a fragmentary fossil from Rhynie, Rhyniognatha hirsti, is not only the earliest true insect but may be relatively derived within basal Ectognatha. In fact, Rhyniognatha has derived characters shared with winged insects, suggesting that the origin of wings may have been earlier than previously believed. Regardless, Rhyniognatha indicates that insects originated in the Silurian period and were members of some of the earliest terrestrial faunas.