The pygmy marmoset,the smallest of the anthropoid primates,has a broad distribution in Western *** studies using molecular and morphological data have identified two distinct species separated by the Napo and Solimoes...
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The pygmy marmoset,the smallest of the anthropoid primates,has a broad distribution in Western *** studies using molecular and morphological data have identified two distinct species separated by the Napo and Solimoes-Amazonas ***,reconciling this new biological evidence with current taxonomy,i.e.,two subspecies,Cebuella pygmaea pygmaea(Spix,1823)and Cebuella pygmaea niveiventris(Lönnberg,1940),was problematic given the uncertainty as to whether Spix’s pygmy marmoset(Cebuella pygmaea pygmaea)was collected north or south of the Napo and Solimoes-Amazonas rivers,making it unclear to which of the two newly revealed species the name pygmaea would ***,we present the first molecular data from Spix’s type specimen of Cebuella pygmaea,as well as novel mitochondrial genomes from modern pygmy marmosets sampled near the type locality(Tabatinga)on both sides of the *** these data,we can confirm the correct names of the two species identified,i.e.,*** for animals north of the Napo and Solimoes-Amazonas rivers and *** for animals south of these two *** analyses of the novel genetic data placed into the context of cytochrome b gene sequences from across the range of pygmy marmosets further led us to reevaluate the geographical distribution for the two Cebuella *** dated the split of these two species to 2.54 million years *** discuss additional,more recent,subdivisions within each lineage,as well as potential contact zones between the two species in the headwaters of these rivers.
黑珊瑚是一种主要生活在深海的六射珊瑚,与其他六射珊瑚的不同之处在于(1)其珊瑚虫具有六个触手;(2)群居生活;(3)具有灰色或黑色的几丁质骨骼。黑珊瑚唯一已知的化石记录来自于中国南部湖北省早奥陶世分乡组(470 ma)。本文我们报告了来自南澳大利亚寒武纪阿加西组(约515ma)的黑珊瑚化石星射狼牙棒虫(Kanabopathes stellatus gen. et sp. nov)。化石具有中空的轴,沿着中轴具有五列三角形的尖刺,横截面呈现同心环形结构。这是目前已知最早的六射珊瑚。结合它们与寒武纪古杯礁共同保存这一特征,我们推测,(1)寒武纪黑珊瑚生活在一个清洁、温暖、强波浪的大陆架环境中。(2)它们的几丁质骨架可能适应支持螅肉附着,竞争海底下层微型食物。(3)在随后地史时期,黑珊瑚很可能逐渐迁入深海。(4)现生黑珊瑚与化石极为相似,表明黑珊瑚的演化异常缓慢。(5)包括黑珊瑚在内的六射珊瑚化石应该出现在寒武纪第四期或更早,而不是出现在二叠纪-三叠纪界线之后。
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