Department of Zoology, The Natural History Museum, Cromwell Road, London, UK.
Arthropod Struct Dev. 2010 Mar-May;39(2-3):143-53. doi: 10.1016/j.asd.2009.11.001. Epub 2009 Nov 28.
This paper presents an overview of current hypotheses of higher-level crustacean phylogeny in order to assist and help focus further research. It concentrates on hypotheses proposed or debated in the recent literature based on morphological, molecular and combined evidence phylogenetic analyses. It can be concluded that crustacean phylogeny remains essentially unresolved. Conflict is rife, irrespective of whether one compares different morphological studies, molecular studies, or both. Using the number of recently proposed alternative sister group hypotheses for each of the major tetraconatan taxa as a rough estimate of phylogenetic uncertainty, it can be concluded that the phylogenetic position of Malacostraca remains the most problematic, closely followed by Branchiopoda, Cephalocarida, Remipedia, Ostracoda, Branchiura, Copepoda and Hexapoda. Future progress will depend upon a broader taxon sampling in molecular analyses, and the further exploration of new molecular phylogenetic markers. However, the need for continued revision and expansion of morphological datasets remains undiminished given the conspicuous lack of agreement between molecules and morphology for positioning several taxa. In view of the unparalleled morphological diversity of Crustacea, and the likely nesting of Hexapoda somewhere within Crustacea, working out a detailed phylogeny of Tetraconata is a crucial step towards understanding arthropod body plan evolution.
本文概述了当前高级甲壳动物系统发育的假说，以协助和帮助进一步研究。它集中在基于形态、分子和综合证据的系统发育分析提出或争论的假说。可以得出结论，甲壳动物的系统发育仍然没有得到根本解决。无论比较不同的形态研究、分子研究，还是两者的结合，冲突都很普遍。根据每个主要四足甲壳动物类群最近提出的替代姐妹群假说的数量，作为系统发育不确定性的粗略估计，可以得出结论，软甲纲的系统发育位置仍然是最成问题的，紧随其后的是鳃足纲、甲壳纲、介形纲、介形纲、鳃足纲、桡足纲和六足纲。未来的进展将取决于分子分析中更广泛的分类群采样，以及对新的分子系统发育标记的进一步探索。然而，鉴于某些分类群的分子与形态之间明显缺乏一致性，因此继续修订和扩展形态数据集的需求仍然没有减少。鉴于甲壳动物无与伦比的形态多样性，以及六足动物可能在甲壳动物内部的某个位置，详细研究四足甲壳动物的系统发育是理解节肢动物体节进化的关键步骤。
