Museum für Naturkunde, Leibniz Institute for Research on Evolution and Biodiversity at the Humboldt University Berlin, Invalidenstr. 43, 10115 Berlin, Germany.
Mol Phylogenet Evol. 2010 Feb;54(2):395-404. doi: 10.1016/j.ympev.2009.07.029. Epub 2009 Jul 30.
Angel sharks of the genus Squatina represent a group comprising 22 extant benthic species inhabiting continental shelves and upper slopes. In the present study, a comprehensive phylogenetic reconstruction of 17 Squatina species based on two mitochondrial markers (COI and 16S rRNA) is provided. The phylogenetic reconstructions are used to test biogeographic patterns. In addition, a molecular clock analysis is conducted to estimate divergence times of the emerged clades. All analyses show Squatina to be monophyletic. Four geographic clades are recognized, of which the Europe-North Africa-Asia clade is probably a result of the Tethys Sea closure. A second sister group relationship emerged in the analyses, including S. californica (eastern North Pacific) and S. dumeril (western North Atlantic), probably related to the rise of the Panamanian isthmus. The molecular clock analysis show that both lineage divergences coincide with the estimated time of these two geological events.
角鲨属的天使鲨代表了一个由 22 种现存的底栖物种组成的群体，它们栖息在大陆架和上斜坡。在本研究中，基于两个线粒体标记物（COI 和 16S rRNA），对角鲨属的 17 种物种进行了全面的系统发育重建。系统发育重建用于测试生物地理模式。此外，还进行了分子钟分析，以估计已出现的进化枝的分歧时间。所有分析均表明角鲨属为单系群。共识别出四个地理分支，其中欧洲-北非-亚洲分支可能是特提斯海关闭的结果。在分析中还出现了第二个姐妹群关系，包括东太平洋的 S. californica 和西大西洋的 S. dumeril，可能与巴拿马地峡的崛起有关。分子钟分析表明，这两个谱系的分歧与这两个地质事件的估计时间相一致。
