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首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >Fossil Evidence For The Origin Of Spider Spinnerets, And A Proposed Arachnid Order
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Fossil Evidence For The Origin Of Spider Spinnerets, And A Proposed Arachnid Order

机译：蜘蛛喷丝板起源的化石证据以及拟议的蜘蛛纲

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摘要

Silk production from opisthosomal glands is a defining characteristic of spiders (Araneae). Silk emerges from spigots (modified setae) borne on spinnerets (modified appendages). Spigots from Attercopus fimbriunguis, from Middle Devonian (386 Ma) strata of Gilboa, New York, were described in 1989 as evidence for the oldest spider and the first use of silk by animals. Slightly younger (374 Ma) material from South Mountain, New York, conspecific with A. fimbriunguis, includes spigots and other evidence that elucidate the evolution of early Araneae and the origin of spider silk. No known Attercopus spigots, including the original specimen, occur on true spinnerets but are arranged along the edges of plates. Spinnerets originated from biramous appendages of opisthosomal somites 4 and 5; although present in Limulus, no other arachnids have opisthosomal appendage homologues on these segments. The spigot arrangement in Attercopus shows a primitive state before the reexpression of the dormant genetic mechanism that gave rise to spinnerets in later spiders. Enigmatic flagellar structures originally described as Arachnida incertae sedis, are shown to be Attercopus anal flagella, as found in Permarachne, also originally described as a spider. An arachnid order, Uraraneida, is erected for a plesion, including these two genera, based on this combination of characters. The inability of Uraraneida precisely to control silk weaving suggests its original use as a wrapping, lining, or homing material.
机译：来自阿斯匹索体腺体的丝生产是蜘蛛（Araneae）的明确特征。丝绸从喷丝头（修饰的附属物）上携带的插穗（修饰的刚毛）出来。 1989年，来自纽约吉尔伯州中泥盆纪（386 Ma）地层的Attercopus fimbriunguis的子芽被描述为最古老的蜘蛛和动物首次使用丝绸的证据。来自纽约南山的稍年轻（374毫安）的材料，与纤毛曲霉同种，包括栓钉和其他证据，阐明了早期Araneae的进化和蜘蛛丝的起源。真正的喷丝头上没有出现已知的Attercopus凸台，包括原始标本，但沿板的边缘排列。喷丝头起源于阿司匹林体4和5的双峰附肢；尽管存在于Li中，但没有其他蜘蛛纲动物在这些节段上具有阿片体附属物。 Attercopus中的子突排列显示了处于休眠遗传机制的重新表达之前的原始状态，该遗传机制在后来的蜘蛛中产生了喷丝头。如在Permarachne中发现的最初被描述为蜘蛛的神秘鞭毛结构被证明是肛门鞭毛的Attercopus肛门鞭毛。根据这些字符的组合，建立了一个蛛网纲动物Uraraneida，以包括这两个属在内的一个褶皱。 Uraraneida无法精确控制丝绸的编织，这表明它最初用作包裹，衬里或归巢材料。

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