Phylogenetic Systematics and Evolution Research Group, Section of Taxonomy and Evolution, Department of Natural History, University Museum of Bergen, University of Bergen, PB 7800, 5020 Bergen, Norway.
Muséum National d'Histoire Naturelle, UMR 7205, ISyEB, 55 rue de Buffon, F-75231 Paris cedex 05, France.
Mol Phylogenet Evol. 2015 Aug;89:130-50. doi: 10.1016/j.ympev.2015.04.011. Epub 2015 Apr 24.
The Cephalaspidea is a diverse marine clade of euthyneuran gastropods with many groups still known largely from shells or scant anatomical data. The definition of the group and the relationships between members has been hampered by the difficulty of establishing sound synapomorphies, but the advent of molecular phylogenetics is helping to change significantly this situation. Yet, because of limited taxon sampling and few genetic markers employed in previous studies, many questions about the sister relationships and monophyletic status of several families remained open. In this study 109 species of Cephalaspidea were included covering 100% of traditional family-level diversity (12 families) and 50% of all genera (33 genera). Bayesian and maximum likelihood phylogenetics analyses based on two mitochondrial (COI, 16S rRNA) and two nuclear gene markers (28S rRNA and Histone-3) were used to infer the relationships of Cephalaspidea. The monophyly of the Cephalaspidea was confirmed. The families Cylichnidae, Diaphanidae, Haminoeidae, Philinidae, and Retusidae were found non-monophyletic. This result suggests that the family level taxonomy of the Cephalaspidea warrants a profound revision and several new family and genus names are required to reflect the new phylogenetic hypothesis presented here. We propose a new classification of the Cephalaspidea including five new families (Alacuppidae, Colinatydidae, Colpodaspididae, Mnestiidae, Philinorbidae) and one new genus (Alacuppa). Two family names (Acteocinidae, Laonidae) and two genera (Laona, Philinorbis) are reinstated as valid. An additional lineage with family rank (Philinidae "Clade 4") was unravelled, but no genus and species names are available to reflect the phylogeny and formal description will take place elsewhere.
头楯目是一个多样化的海洋后鳃类腹足纲动物群，许多群体仍然主要通过壳或少量解剖学数据来了解。由于难以建立可靠的同源特征，该群体的定义和成员之间的关系一直受到阻碍，但分子系统发生学的出现正在帮助显著改变这种情况。然而，由于以前的研究中有限的分类群采样和很少使用遗传标记，关于几个科的姐妹关系和单系性的许多问题仍然没有答案。在这项研究中，包括了 109 种头楯目，涵盖了 100%的传统科级多样性（12 个科）和 50%的所有属（33 个属）。基于两个线粒体（COI、16S rRNA）和两个核基因标记（28S rRNA 和组蛋白 3）的贝叶斯和最大似然系统发育分析被用来推断头楯目的关系。头楯目的单系性得到了确认。Cylichnidae、Diaphanidae、Haminoeidae、Philinidae 和 Retusidae 科被发现不是单系的。这一结果表明，头楯目科的分类需要进行深刻的修订，需要几个新的科名和属名来反映这里提出的新的系统发育假说。我们提出了一个新的头楯目分类，包括五个新科（Alacuppidae、Colinatydidae、Colpodaspididae、Mnestiidae、Philinorbidae）和一个新属（Alacuppa）。两个科名（Acteocinidae、Laonidae）和两个属名（Laona、Philinorbis）被恢复为有效。一个具有科级地位的额外谱系（Philinidae“Clade 4”）被揭示出来，但没有属名和种名可以反映出系统发育，正式描述将在其他地方进行。
