从弹尾纲和原尾纲的亲缘关系质疑缺尾纲（=近昆虫纲）的有效性

鉴于弹尾目（跳虫）和原尾目的尾部都没有尾须（cerci），Brner于1910年就把这两类归并为一个类群缺尾纲（Ellipura），这一分类阶元长期被许多昆虫学家沿用至今。Kukalová-Peck(1987 )在讨论化石双尾虫（?）附肢的总体结构（ground plan）时，认为跳虫和原尾虫的腹部侧板更原始，附肢无转节，将二者归纳成近昆虫纲（Parainsecta）。但是从形态特征、内部结构、比较精子学、变态类型和胚后发育等的特点以及线粒体DNA和核糖体DNA的测序分析结果，显示弹尾纲与原尾纲之间存在诸多重要差异，不具备较为密切的亲缘关系，我们不支持（弹尾纲+原尾纲）组成缺尾纲或近昆虫纲。据此建议取消缺尾纲（=近昆虫纲）这一分类阶元。

On the validity of the class Ellipura ( = Parainsecta) (Hexapoda) based on the phylogenetic relationship between Collembola and Protura

According to the absence of the cerci in both Collembola and Protura, Borner in 1910 grouped them together into a class Ellipura, which has long been supported by many entomologists in the world. As Kukalova-Peck (1987) discussed about the ground plan of the appendages of a fossil Diplura (?), she concludedt hat Collembola and Protura differ in having a more primitive abdominal pleuron which does not include the trochanter, and should be classified as sister groups, (Protura+Collembola) Parainsecta. But the evidences from the comparison in morphology, internal structures, comparative spermatology, morphogenesis and post-embryonic development, as well as the data of the molecular sequences between Collembola and Protura, did not lead to a close relationship. Therefore, the grouping of Protura and Collembola together as a monophylum is not supported. The assemblage Ellipura (=Parainsecta) should be rejected.