Phylogenetic analyses of sequences of the 18S rDNA and MT‐CO2 gene fragments indicated that the oviparous and viviparous gyrodactylid‐like monogenoids formed independent monophyletic clades within the Order Gyrodactylidea, supporting the reinstatement of the Oogyrodactylidae and limiting the Gyrodactylidae to the viviparous species. Analyses further indicated that the clade comprising the two families shared a common ancestor with the Udonellidae. Two clades, that of Aglaiogyrodactylus and that of Phanerothecium, were identified within the Oogyrodactylidae, while Onychogyrodactylus was shown to be polyphyletic and Oogyrodactylus basal within the family. One putative synapomorphy was identified for the Oogyrodactylidae, that is presence of a massive Mehlis’ gland. The Gyrodactylidae was limited to species having a viviparous mode of reproduction, although relationships within the family were generally poorly resolved. Several putative synapomorphies were found for the Gyrodactylidae, including viviparity and protogyny, a bulbous and armed MCO, absence of a vitellarium, and presence of a knob‐like deep anchor root (Fig. 3e). Ultrametric analyses suggested that the initial divergence of the clade of the gyrodactylid‐like monogenoids and Udonellidae occurred about 335 mya (based on the 18S rDNA fragment) and about 400 mya (based on the MT‐CO2 gene fragment). Using the 18S rDNA fragment and three calibration points, ultrametric analyses indicated that the Gyrodactylidae and Oogyrodactylidae diverged at approximately 278 mya, with initial diversification within the Gyrodactylidae (about 211 mya) occurring earlier than that of the Oogyrodactylidae (about 133 mya), the latter coinciding with the breakup of Gondwana and the initial diversification of the armoured catfishes (Loricariidae). Finally, diagnoses were provided for the Gyrodactylidae and Oogyrodactylidae along with a list of genera assigned to each family.

中文翻译：

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卵生和胎生 gyrodactylids (Monogenoidea, Gyrodactylidea) 的系统发育状况和历史起源

对 18S rDNA 和 MT-CO2 基因片段序列的系统发育分析表明，卵生和胎生 gyrodactylid 样单基因类在 gyrodactylidea 目内形成独立的单系进化枝，支持 Oogyrodactylidae 的恢复，并将 gyrodactylidae 限制在 virodactylidae 物种中。分析进一步表明，包括两个科的进化枝与乌冬虫科有共同的祖先。在 Oogyrodactylidae 中确定了两个进化枝，即 Aglaiogyrodactylus 和 Phanerothecium，而 Onychogyrodactylus 被证明是多系的，而 Oogyrodactylus 则是该科中的基础。为 Oogyrodactylidae 确定了一种推定的突触，即存在巨大的 Mehlis 腺体。Gyrodactylidae 仅限于具有胎生繁殖方式的物种，尽管家庭内部的关系一般都没有得到很好的解决。为 Gyrodactylidae 发现了几种推定的突触，包括胎生和母体，球根状和武装的 MCO，没有 vitellarium，以及存在旋钮状深锚根（图 3e）。超计量分析表明，类旋指类单基因类动物进化枝和 Udonellidae 进化枝的初始分化发生在大约 335 mya（基于 18S rDNA 片段）和大约 400 mya（基于 MT-CO2 基因片段）。使用 18S rDNA 片段和三个校准点，超量分析表明 Gyrodactylidae 和 Oogyrodactylidae 在大约 278 mya 分叉，Gyrodactylidae（约 211 mya）内的初始多样化发生早于 Oogyrodactylidae（约 133 mya），后者恰逢冈瓦纳大陆的解体和装甲鲶科（Loricariidae）的最初多样化。最后，提供了 Gyrodactylidae 和 Oogyrodactylidae 的诊断以及分配给每个科的属列表。