Third Department of Zoology, Natural History Museum of Vienna, Burgring 7, 1010, Vienna, Austria.
Canadian National Collection of Insects, Arachnids and Nematodes, Agriculture and Agri-Food Canada, 960 Carling Avenue, Ottawa, K1A 0C6, ON, Canada.
Sci Rep. 2017 Oct 11;7(1):12972. doi: 10.1038/s41598-017-13207-4.
Massive biotic change occurred during the Eocene as the climate shifted from warm and equable to seasonal and latitudinally stratified. Mild winter temperatures across Arctic intercontinental land bridges permitted dispersal of frost-intolerant groups until the Eocene-Oligocene boundary, while trans-Arctic dispersal in thermophilic groups may have been limited to the early Eocene, especially during short-lived hyperthermals. Some of these lineages are now disjunct between continents of the northern hemisphere. Although Eocene climate change may have been one of the most important drivers of these ancient patterns in modern animal and plant distributions, its particular events are rarely implicated or correlated with group-specific climatic requirements. Here we explored the climatic and geological drivers of a particularly striking Neotropical-Oriental disjunct distribution in the rove beetle Bolitogyrus, a suspected Eocene relict. We integrated evidence from Eocene fossils, distributional and climate data, paleoclimate, paleogeography, and phylogenetic divergence dating to show that intercontinental dispersal of Bolitogyrus ceased in the early Eocene, consistent with the termination of conditions required by thermophilic lineages. These results provide new insight into the poorly known and short-lived Arctic forest community of the Early Eocene and its surviving lineages.
大规模的生物变化发生在始新世，当时气候从温暖和均衡转变为季节性和纬度分层。北极洲际陆桥温和的冬季温度允许不耐寒的群体扩散，直到始新世-渐新世边界，而在嗜热群体中的跨北极扩散可能仅限于始新世早期，尤其是在短暂的超热期间。这些谱系中的一些现在在北半球的大陆之间被隔开。尽管始新世气候变化可能是现代动植物分布中这些古老模式的最重要驱动因素之一，但它的特定事件很少与特定群体的气候要求相关或相关。在这里，我们探讨了在一种特别引人注目的新热带-东方间断分布中的摇蚊 Bolitogyrus 中的气候和地质驱动因素，这是一种疑似始新世遗迹。我们综合了始新世化石、分布和气候数据、古气候、古地理和系统发育分歧日期的证据，表明 Bolitogyrus 的洲际扩散在始新世早期停止，这与嗜热谱系所需条件的终止一致。这些结果为人们对早始新世鲜为人知且短暂的北极森林群落及其幸存的谱系有了新的认识。
