骨舌鱼超目的系统发育关系

通过对中国化石骨舌鱼类及骨舌鱼类现生主要类群的比较研究,用 PAUP 软件对31个分类单元的65个特征进行了分析,得到了16个最简约的分支图(步长为206,一致性指数为 0．4320,保留指数为0．7194)。严格合意树显示,中国早白垩世的骨舌鱼类(酒泉鱼、狼鳍鱼、固阳鱼、吉南鱼、同心鱼、西夏鱼、昆都仑鱼和华夏鱼)主要为骨舌鱼超目中不同等级的干群；与一般的观点不同,始舌齿鱼与蛟河鱼组成了姊妹群关系；骨舌鱼目由 Thaumaturus、弓背鱼亚目和骨舌鱼亚目组成；弓背鱼类与象鼻鱼类关系更近；Ostariostoma 为弓背鱼科的姊妹群；副狼鳍鱼与[骨舌鱼亚科+犁齿鱼亚科]组成了姊妹群,该姊妹群关系的建立,将骨舌鱼科的历史延伸到了早白垩世。

PHYLOGENY OF OSTEOGLOSSOMORPHA

Based on extensive morphological studies of the Chinese fossil osteoglossomorphs as well as the representatives of the major lineages of living osteoglossomorphs,I present the result of a cladistic analysis of 65 characters in 31 taxa,conducted using PAUP software(version 4.0b10).Strict consen- sus tree of 16 equally parsimonious trees(tree length of 206 steps,consistency index of 0.4320,reten- tion index of 0.7194)shows that the Chinese Early Cretaceous osteoglossomorphs(Jiuquanichthys,Ly- eoptera,Kuyangichthys,Jinanichthys,Tongxinichthys,Xixiaichthys,Kuntulunia and Huashia)are mostly stem-groups of the superorder at different levels;Eohiodon and Jiaohichthys are interpreted as sister group rather than generally accepted Eohiodon and Hiodon;Osteoglossiformes consists of Thau- maturus,Notopteroidei and Osteoglossoidei;Notopterids are more closely related to mormyrids than to osteoglossids;Ostariostoma is the sister group to Notopteridae;Osteoglossoidei is coextensive with Os- teoglossidae;Paralycoptera is a sister group to[Osteoglossinae Phareodontinae].The suggestion of a sister group relationship between Paralycoptera and[Osteoglossinae Phareodontinae]extends the range of Osteoglossidae back to Early Cretaceous.