A review of the systematic biology of fossil and living bony-tongue fishes, Osteoglossomorpha (Actinopterygii: Teleostei)

ABSTRACT The bony-tongue fishes, Osteoglossomorpha, have been the focus of a great deal of morphological, systematic, and evolutionary study, due in part to their basal position among extant teleostean fishes. This group includes the mooneyes (Hiodontidae), knifefishes (Notopteridae), the abu (Gymnarchidae), elephantfishes (Mormyridae), arawanas and pirarucu (Osteoglossidae), and the African butterfly fish (Pantodontidae). This morphologically heterogeneous group also has a long and diverse fossil record, including taxa from all continents and both freshwater and marine deposits. The phylogenetic relationships among most extant osteoglossomorph families are widely agreed upon. However, there is still much to discover about the systematic biology of these fishes, particularly with regard to the phylogenetic affinities of several fossil taxa, within Mormyridae, and the position of Pantodon. In this paper we review the state of knowledge for osteoglossomorph fishes. We first provide an overview of the diversity of Osteoglossomorpha, and then discuss studies of the phylogeny of Osteoglossomorpha from both morphological and molecular perspectives, as well as biogeographic analyses of the group. Finally, we offer our perspectives on future needs for research on the systematic biology of Osteoglossomorpha.

摘要 骨舌鱼类（bony-tongue fishes）隶属于骨舌鱼总目（Osteoglossomorpha），因其在现生真骨鱼类中处于基干演化位置，长期以来是形态学、分类学与演化生物学研究的热点类群。该类群包含月眼鱼科（Hiodontidae）、驼背鱼科（Notopteridae）、裸臀鱼科（Gymnarchidae）、象鼻鱼科（Mormyridae）、骨舌鱼科（Osteoglossidae，涵盖龙鱼与巨骨舌鱼（pirarucu）），以及非洲蝴蝶鱼科（Pantodontidae，即非洲蝴蝶鱼）。这一形态特征高度异质性的类群拥有漫长且多样的化石记录，其化石类群遍布全球各大陆，涵盖淡水与海相沉积地层。当前，现生骨舌鱼总目多数科间的系统发育关系已达成广泛共识。但该类群的分类生物学仍有诸多未解之谜，尤其集中于部分化石类群的系统发育亲缘关系、象鼻鱼科内部的演化关系，以及非洲蝴蝶鱼属（Pantodon）的演化位置。本文综述了骨舌鱼总目鱼类的研究现状：首先概述骨舌鱼总目的物种多样性，随后从形态学与分子生物学视角梳理该类群的系统发育研究进展，并探讨相关生物地理学分析成果；最后展望了骨舌鱼总目分类生物学未来的研究方向与需求。