加拿大卑詩省的伯吉斯頁巖以含有各種各樣軟體動物化石而出名,，這些動物來自寒武紀中期,，距今約5.1億年前，它們提供了一個了解早期海洋動物的窗口。現(xiàn)在,，人們知道類似的動物來自相距非常遠的不同地方，如中國和格陵蘭,，但過去有關證據似乎表明,，這些動物在寒武紀中期滅絕了。實際上不是這樣的,。
一種“伯吉斯頁巖型”動物群落已在摩洛哥的Lower Fezouata 和Upper Fezouata構造中發(fā)現(xiàn),，其時間在距今約4.80億-4.72億年前的早奧陶世,。 這種類型的動物在寒武紀之后顯然還存在,，之所以這樣，既與軟體化石保存機會有關,，也同樣與滅絕和存活有關,。Fezouata生物區(qū)系為伯吉斯頁巖群落和“奧陶系大規(guī)模生物多樣化事件”（海洋生命史中最大事件之一，以前幾乎全部由有殼類動物化石來代表）的早期階段提供了一個聯(lián)系,。
本期Nature封面所示為來自Fezouata生物區(qū)系的一種marrellomorph節(jié)肢動物（很可能是Furca sp.）,。（生物谷Bioon.com）
生物谷推薦原文出處：
Nature doi:10.1038/nature09038
Ordovician faunas of Burgess Shale type
Peter Van Roy,Patrick J. Orr,Joseph P. Botting,Lucy A. Muir,Jakob Vinther,Bertrand Lefebvre,Khadija el Hariri& Derek E. G. Briggs
The renowned soft-bodied faunas of the Cambrian period, which include the Burgess Shale, disappear from the fossil record in the late Middle Cambrian, after which the Palaeozoic fauna1 dominates. The disappearance of faunas of Burgess Shale type curtails the stratigraphic record of a number of iconic Cambrian taxa. One possible explanation for this loss is a major extinction2, 3, but more probably it reflects the absence of preservation of similar soft-bodied faunas in later periods4. Here we report the discovery of numerous diverse soft-bodied assemblages in the Lower and Upper Fezouata Formations (Lower Ordovician) of Morocco, which include a range of remarkable stem-group morphologies normally considered characteristic of the Cambrian. It is clear that biotas of Burgess Shale type persisted after the Cambrian and are preserved where suitable facies occur. The Fezouata biota provides a link between the Burgess Shale communities and the early stages of the Great Ordovician Biodiversification Event.
