Tropical ochrophyte algae from the Eocene of northern Canada: A biogeographic response to past global warming
Tropical ochrophyte algae from the Eocene of northern Canada: A biogeographic response to past global warming
复制标题
加拿大北部始新世的热带黄藻：对过去全球变暖的生物地理学反应
DOI：
10.2110/palo.2007-p07-077r
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发表时间：
2009
影响因子：
4.1
通讯作者：
A. P. Wolfe
中科院分区：
文献类型：
--
作者：
P. Siver;A. P. Wolfe
摘要本文报道了加拿大北方始新世中期湖泊沉积物中保存完好的淡水硅质藻类标本，它们分别属于合脉藻纲和硅藻纲。当考虑到最接近的现存亲属的背景下，这些微体化石提出明确的地理和生态的亲和性与暖水ochrophyte组合。我们已经确定了明确分配到Mallomonasbangladeshica，金藻，现在仅限于热带湖泊生态系统的规模。硅藻属Actinella在这些沉积物中也有很好的代表性，再次与热带至亚热带地区，特别是南半球发现的最具可比性的现存同系物。我们推测，在始新世温室古气候时期，湖相藻类发生了根本的地理重组。在这种情况下，未来的气候变暖应被视为一个强大的矢量类似的社区转变，伴随着湖沼学的影响。
Abstract We report on exquisitely preserved specimens of freshwater siliceous algae belonging to the classes Synurophyceae (scaled chrysophytes) and Bacillariophyceae (diatoms) from middle Eocene lake sediments in Northern Canada. When considered in the context of closest extant relatives, these microfossils present unequivocal biogeographic and ecological affinities with warm-water ochrophyte assemblages. We have identified scales that are unambiguously assigned to Mallomonas bangladeshica, a chrysophyte now restricted to tropical lake ecosystems. The diatom genus Actinella is also well represented in these sediments, again with the most comparable extant congeners found in tropical to subtropical localities, particularly in the Southern Hemisphere. We surmise that fundamental biogeographic reorganizations among lacustrine algae took place during Eocene hothouse paleoclimates. In this light, future climate warming should be viewed as a potent vector for similar community shifts, with attendant limnological implications.