The evolution of the coleopteran suborder Adephaga is discussed based on a robust phylogenetic background. Analyses of morphological characters yield results nearly identical to recent molecular phylogenies, with the highly specialized Gyrinidae placed as sister to the remaining families, which form two large, reciprocally monophyletic subunits, the aquatic Haliplidae + Dytiscoidea (Meruidae, Noteridae, Aspidytidae, Amphizoidae, Hygrobiidae, Dytiscidae) on one hand, and the terrestrial Geadephaga (Trachypachidae + Carabidae) on the other. The ancestral habitat of Adephaga, either terrestrial or aquatic, remains ambiguous. The former option would imply two or three independent invasions of aquatic habitats, with very different structural adaptations in larvae of Gyrinidae, Haliplidae and Dytiscoidea.

中文翻译：

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Adephaga（鞘翅目）的形态进化

基于强大的系统发育背景讨论了鞘翅目亚目 Adephaga 的进化。形态特征分析产生的结果与最近的分子系统发育几乎相同，高度特化的 Gyrinidae 作为其余家族的姐妹，形成两个大的、相互单系的亚基，水生 Haliplidae + Dytiscoidea（Meruidae、Noteridae、Apidytidae、Amphizoidae、Hygrobiidae , Dytiscidae) 一方面，另一方面是陆生 Geadephaga (Trachypahidae + Carabidae)。Adephaga 的祖先栖息地，无论是陆地还是水生，仍然不明确。前一种选择意味着两到三个独立的水生栖息地入侵，在 Gyrinidae、Haliplidae 和 Dytiscoidea 的幼虫中具有非常不同的结构适应性。