Bonytongues (Osteoglossomorpha) constitute an ancient clade of teleost fishes distributed in freshwater habitats throughout the world. The group includes well-known species such as arowanas, featherbacks, pirarucus, and the weakly electric fishes in the family Mormyridae. Their disjunct distribution, extreme morphologies, and electrolocating capabilities (Gymnarchidae and Mormyridae) have attracted much scientific interest, but a comprehensive phylogenetic framework for comparative analysis is missing, especially for the species-rich family Mormyridae. Of particular interest are disparate craniofacial morphologies among mormyrids which might constitute an exceptional model system to study convergent evolution. We present a phylogenomic analysis based on 546 exons of 179 species (out of 260), 28 out of 29 genera, and all six families of extant bonytongues. Based on a recent reassessment of the fossil record of osteoglossomorphs, we inferred dates of divergence among transcontinental clades and the major groups. The estimated ages of divergence among extant taxa (e.g., Osteoglossomorpha, Osteoglossiformes, and Mormyroidea) are older than previous reports, but most of the divergence dates obtained for clades on separate continents are too young to be explained by simple vicariance hypotheses. Biogeographic analysis of mormyrids indicates that their high species diversity in the Congo Basin is a consequence of range reductions of previously widespread ancestors and that the highest diversity of craniofacial morphologies among mormyrids originated in this basin. Special emphasis on a taxon-rich representation for mormyrids revealed pervasive misalignment between our phylogenomic results and mormyrid taxonomy due to repeated instances of convergence for extreme craniofacial morphologies. Estimation of ancestral phenotypes revealed contingent evolution of snout elongation and unique projections from the lower jaw to form the distinctive Schnauzenorgan. Synthesis of comparative analyses suggests that the remarkable craniofacial morphologies of mormyrids evolved convergently due to niche partitioning, likely enabled by interactions between their exclusive morphological and electrosensory adaptations. [Africa; ancestral state estimation; diversity; exon capture; freshwater fishes; Phylogenomics.]

中文翻译：

---

骨舌鱼（Osteoglossomorpha）的系统基因组学揭示了弱电进化枝（Mormyridae）的颅面进化和生物地理学

骨舌鱼 (Osteoglossomorpha) 是硬骨鱼的古老分支，分布于世界各地的淡水栖息地。该组包括众所周知的物种，如龙鱼、羽背鱼、pirarucus 和 Mormyridae 家族的弱电鱼。它们的分离分布、极端形态和电定位能力（Gymnarchidae 和 Mormyridae）吸引了很多科学兴趣，但缺乏用于比较分析的全面系统发育框架，特别是对于物种丰富的 Mormyridae 家族。特别令人感兴趣的是mormyrids之间不同的颅面形态，这可能构成研究趋同进化的特殊模型系统。我们基于 179 个物种（260 个）、29 个属中的 28 个、546 个外显子进行系统基因组分析，以及现存的所有六个骨舌科。根据最近对骨舌形动物化石记录的重新评估，我们推断出跨大陆进化枝和主要群体之间分歧的日期。现存分类群（例如，Osteoglossomorpha、Osteoglossiformes 和 Mormyroidea）之间分歧的估计年龄比以前的报告要早，但是从不同大陆上的进化枝获得的大多数分歧日期都太年轻，无法用简单的变异假设来解释。对mormyrids 的生物地理分析表明，它们在刚果盆地的高度物种多样性是以前广泛分布的祖先的范围减少的结果，并且mormyrids 中颅面形态的最高多样性起源于该盆地。特别强调 mormyrids 的丰富分类表示揭示了我们的系统基因组结果和 mormyrid 分类之间普遍存在的错位，这是由于极端颅面形态的反复收敛实例。对祖先表型的估计揭示了鼻子伸长的偶然演变和下颌独特的突起形成独特的 Schnauzenorgan。比较分析的综合表明，由于生态位分区，mormyrids 显着的颅面形态趋同进化，这可能是由于它们独有的形态学和电感应适应之间的相互作用。[非洲; 祖先状态估计；多样性; 外显子捕获；淡水鱼；系统基因组学。] 比较分析的综合表明，由于生态位分区，mormyrids 显着的颅面形态趋同进化，这可能是由于它们独有的形态学和电感应适应之间的相互作用。[非洲; 祖先状态估计；多样性; 外显子捕获；淡水鱼；系统基因组学。] 比较分析的综合表明，由于生态位分区，mormyrids 显着的颅面形态趋同进化，这可能是由于它们独有的形态学和电感应适应之间的相互作用。[非洲; 祖先状态估计；多样性; 外显子捕获；淡水鱼；系统基因组学。]