Charbonnier S, Vannier J, Riou B
UMR 5125 PEPS, CNRS, Université Lyon 1, Campus de la Doua, Bâtiment Géode, 69622 Villeurbanne Cedex, France.
Proc Biol Sci. 2007 Oct 22;274(1625):2555-61. doi: 10.1098/rspb.2007.0848.
The diverse and exceptionally well-preserved pycnogonids described herein from the Middle Jurassic La Voulte Lagerstätte fill a 400 Myr gap of knowledge in the evolutionary history of this enigmatic group of marine arthropods. They reveal very close morphological and functional (locomotion, feeding) similarities with present-day pycnogonids and, by contrast, marked differences with all Palaeozoic representatives of the group. This suggests a relatively recent, possibly Mesozoic origin for at least three major extant lineages of pycnogonids (Ammotheidae, Colossendeidae, Endeidae). Combined evidence from depositional environment, faunal associates and recent analogues indicate that the La Voulte pycnogonids probably lived in the upper bathyal zone (ca 200 m). Our results point to a remarkable morphological and ecological stability of this arthropod group over at least 160 Myr and suggest that the colonization of the deep sea by pycnogonids occurred before the Jurassic.
本文描述的来自中侏罗世拉沃尔特化石库的多样且保存异常完好的海蜘蛛填补了这一神秘海洋节肢动物类群进化史上4亿年的知识空白。它们与现今的海蜘蛛在形态和功能（运动、进食）上显示出非常密切的相似性，相比之下，与该类群所有古生代代表存在显著差异。这表明海蜘蛛至少三个主要现存谱系（海蛛科、巨海蛛科、长柱海蛛科）的起源相对较近，可能是中生代。来自沉积环境、动物群伴生种和现代类似物的综合证据表明，拉沃尔特海蜘蛛可能生活在水深约200米的上半深海带。我们的结果表明，这一节肢动物类群在至少1.6亿年的时间里具有显著的形态和生态稳定性，并表明海蜘蛛在侏罗纪之前就已栖息于深海。
