ENVIRONMENTAL FRAMEWORK OF THE DIVERSIFICATION OF THE OSTEOSTRACI DURING THE SILURIAN AND DEVONIAN
ENVIRONMENTAL FRAMEWORK OF THE DIVERSIFICATION OF THE OSTEOSTRACI DURING THE SILURIAN AND DEVONIAN
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DOI：
10.1098/rstb.1985.0086
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发表时间：
1985-01-01
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影响因子：
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通讯作者：
JANVIER, P
中科院分区：
文献类型：
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作者：
JANVIER, P
泥盆纪开始时，脊椎动物群突然大量出现，通常与古红砂岩型寒武相有关。在志留纪甚至奥陶纪已经有代表的少数群体，穿过志留纪-泥盆纪界线，似乎在他们历史的这个特殊时刻经历了重要的多样化。的情况下，Osteostraci，一组化石无颌脊椎动物，详细检查，以显示其系统发育模式是否显示辐射，正好与老红砂岩相在北大西洋大陆的延伸。看来，这一地质事件可能引发了辐射的角骨介类，虽然这个单系群必须已经开始多样化中志留世。三个osteostracan轴承的地方（威尔士边境，斯匹次卑尔根和萨雷马）的分析的审查，并得出结论，Osteostraci可能包括淡水和海洋物种。当在海洋中时，骨介类的环境可能是广阔的潮间带，几乎没有任何现代的等价物。将古红砂岩（来自英国和其他地方）归属于任何明确的环境的困难可能是因为地球的物理常数或潮汐的振幅在泥盆纪早期与现在不同。
The beginning of the Devonian is marked by the sudden occurrence of abundant vertebrate faunas, often associated with detritic facies of Old Red Sandstone type. A few groups, already represented in the Silurian and even in the Ordovician, pass through the Silurian-Devonian boundary and seem to undergo an important diversification at this particular moment of their history. The case of the Osteostraci, a group of fossil jawless vertebrates, is examined in detail to show whether or not its phylogenetic pattern displays a radiation that coincides with the extension of the Old Red Sandstone facies over the North Atlantic continent. It appears that this geological event may have triggered the radiation of the cornuate osteostracans, although this monophyletic group must have already begun to diversify in the Middle Silurian. A review of the analyses of three osteostracan-bearing localities (Welsh Borderland, Spitsbergen and Saaremaa) is presented, and it is concluded that the Osteostraci may have consisted of both fresh water and marine species. When marine, the environment of the Osteostraci may have been vast intertidal zones, hardly having any Recent equivalent. The difficulty in assigning the Old Red Sandstone (from Britain and elsewhere) to any clear-cut environment may be because the physical constants of the Earth or the amplitudes of the tide were not the same in early Devonian times as they are now.