Evolutionary process of planktonic marine diatoms during the late Cenozoic Era.

通过对中高纬度北太平洋、低纬度热带太平洋和南大洋深海岩芯硅藻的详细分析，揭示了这3个海洋浮游硅藻类群的动态演化过程。十字甲藻属（Crucidenticula）是一个已灭绝的暖水硅藻属，由4个演化谱系组成，在中新世早期至中期的暖期，各谱系的地理分布向高纬度地区扩展。已灭绝的拟齿硅藻属（Denticulopsis）由7个谱系组成，除一个世界分布谱系外，大部分为冷水硅藻，显示出典型的两极地理格局。Neodenticula是一个现存于晚中新世的冷水硅藻群。在中新世晚期，它表现出两极分布，但在上新世早期，南大洋种群灭绝。

Dynamic evolutionary processes of the three marine planktonic diatom groups have been revealed by detailed diatom analysis of deep sea cores recovered in the middle- to high-latitude North Pacific, the low-latitude tropical Pacific and the Southern Oceans. Crucidenticula is a warm water extinct diatom genus composed of four evolutionay lineages, each of which expanded its geographic distribution into the high-latitudes during warm period of early to middle Miocene. The extinct diatom genus Denticulopsis consists of seven lineages, most of which are cold water diatoms showing a typical bipolar geographic pattern except for one cosmopolitan lineage. Neodenticula is an extant cold water diatom group born in the late Miocene. It shows a bipolar distribution during the late Miocene, but the Southern Ocean population became extinct in the early Pliocene.