Stasis and diversity in living fossils: Species delimitation and evolution of lingulid brachiopods
Stasis and diversity in living fossils: Species delimitation and evolution of lingulid brachiopods
复制标题
DOI：
10.1016/j.ympev.2022.107460
复制
发表时间：
2022-10-01
影响因子：
4.1
通讯作者：
Endo，Kazuyoshi
中科院分区：
文献类型：
--
作者：
Goto，Ryutaro;Takano，Tsuyoshi;Endo，Kazuyoshi
叶舌科通常被认为是活化石，因为它们自古生代以来几乎没有表现出形态变化。有限的形态变异也使活的舌状科动物的分类学研究具有挑战性。我们调查了现存的lingulids的物种多样性和系统发育关系，并表明，他们是更多样化的实现，表明形态停滞通常伴随着物种形成。根据从东亚、澳大利亚、大洋洲和美洲采集的194份标本的细胞色素氧化酶亚基I（COI）基因序列，种的划分表明，与目前全球公认的11-12种不同，舌形目有14-22种（舌形目9-17种，舌形目4-5种）。四基因系统发育分析支持舌形目和舌形目的姐妹关系。内灵古拉湖拥有大的褐色外壳的adamsi被认为是所有长有或多或少绿色外壳的舌形物种的姐妹。在绿色的Lingulaclade中，L。anatina复合体是包括L. reevei' complex. L。anatina'复合体进一步分为两个主要分支，部分分离的范围集中在（i）温带东亚和（ii）热带中西部太平洋。在Glottidia中，太平洋物种嵌套在大西洋物种中。时间校准的系统发育分析表明，与先前提出的主张新生代起源的假设相反，Lingulalikely起源于白垩纪早期。与先前的假设相反，舌形目和喉形目的分离似乎可以追溯到中生代，而不是石炭纪。总的来说，我们的研究结果揭示了大量的隐蔽的多样性lingulids，这将成为保护和进一步的分类修订的基础。
The Lingulidae are often considered living fossils, because they have shown little morphological change since the Paleozoic. Limited morphological variation has also made the taxonomic study of living lingulids challenging. We investigated species diversity and phylogenetic relationships of extant lingulids and show that they are substantially more diverse than realized, demonstrating that morphological stasis was commonly accompanied by speciation. Species delimitation based on cytochromecoxidase subunit I (COI) gene sequences from 194 specimens sampled from East Asia, Australia, Oceania, and the Americas suggested 14–22 species in the lingulids (9–17 species inLingulaand 4–5 species inGlottidia), in contrast to the 11–12 species currently recognized globally in the family. Four-gene phylogenetic analyses supported the sister relationship betweenLingulaandGlottidia. WithinLingula, L. adamsi, which possesses large, brownish shells, was recovered as sister to all remainingLingulaspecies, which have more or less greenish shells. Within the greenishLingulaclade, the ‘L. anatina’complex was sister to the clade that includes the ‘L. reevei’ complex. The ‘L. anatina’complex was further separated into two major clades with partly separate ranges centered on (i) temperate East Asia, and (ii) the tropical west-central Pacific. WithinGlottidia,Pacific species were nested within Atlantic species. Time-calibrated phylogenetic analyses suggested thatLingulalikely originated in the early Cretaceous contrary to a previously proposed hypothesis advocating a Cenozoic origin. The separation ofLingulaandGlottidiaappears to date from the Mesozoic, not from the Carboniferous, contrary to a previous hypothesis. Overall, our results uncovered substantial cryptic diversity in lingulids, which will form the basis for conservation and further taxonomic revision.