作者：徐光辉，马昕莹，吴飞翔，任艺

摘要：铰齿鱼类是全骨鱼类中的一支，包括现生的雀鳝及其关系密切的化石类型。产自云贵地区中三叠世安尼期(~244 Ma)地层的拱鱼目(Kyphosichthyiformes)鱼类代表了铰齿鱼类最早的化石记录。根据最近在云南罗平关岭组二段发现的4块保存完好的鱼化石，命名了拱鱼目一个新属种，优美玉带鱼(Yudaiichthys eximius gen. et sp. nov.)。新的发现为重新研究拱鱼目和其他早期铰齿鱼类的系统发育关系提供了契机。分支分析结果表明，过去定义的拱鱼科(Kyphosichthyidae)和圣乔治鱼属(Sangiorgioichthys)都是并系类群。重新厘定后的拱鱼目分为拱鱼科和腊山鱼科(Lashanichthyidae fam. nov.); 其中，拱鱼科包括拱鱼属(Kyphosichthys)和富源鱼属(Fuyuanichthys); 苏氏圣乔治鱼(Sangiorgioichthys sui)和羊圈圣乔治鱼(S. yangjuanensis)归入新建的腊山鱼属(Lashanichthys gen. nov.), 和玉带鱼属一起组成腊山鱼科。圣乔治鱼属被移出拱鱼目，限定于产自圣乔治山地区中三叠世拉丁期地层的两个种(Sangiorgioichthys aldae和S. valmarensis); 该属和更进步的铰齿鱼类(半椎鱼目和雀鳝目)构成姐妹群关系。修订后的分支图为了解铰齿鱼类解剖特征的早期演化历史提供了新的见解。
关键词：云南罗平，三叠纪，拱鱼目，铰齿鱼类，骨骼学，系统发育
卷期：第57卷，第3期

A Middle Triassic kyphosichthyiform from Yunnan, China, 
and phylogenetic reassessment of early ginglymodians

Xu Guang-Hui, Ma Xin-Ying, Wu Fei-xiang, Ren Yi  

Abstract    Ginglymodi are a subgroup of holostean fishes, including living gars and their closely-related fossil taxa. The early Middle Triassic (Anisian, ~244 Ma) kyphosichthyiforms from Yunnan and Guizhou, China represent the earliest records of this clade. Here, we report the discovery of a new kyphosichthyiform fish, Yudaiichthys eximius gen. et sp. nov., on the basis of four well-preserved specimens from the second (upper) member of Guanling Formation in Luoping, eastern Yunnan. The new discovery stimulated a phylogenetic analysis to reassess the interrelationships of the Kyphosichthyiformes and their relationships with other early ginglymodians. Results of our analysis indicate that the previously defined family Kyphosichthyidae and the genus Sangiorgioichthys are paraphyletic. A revised Kyphosichthyiformes is proposed here, and it is divided into two families, Kyphosichthyidae and Lashanichthyidae fam. nov. The family Kyphosichthyidae is restricted to include two genera Kyphosichthys and Fuyuanichthys. The Chinese “Sangiorgioichthys” species are removed into a new genus Lashanichthys, which is recovered as a taxon sister to Yudaiichthys gen. nov., and both genera are grouped into the new family, Lashanichthyidae. Sangiorgioichthys is restricted to include two species (S. aldae and S. valmarensis) from the late Middle Triassic (Ladinian) of the Monte San Giorgio area. The genus is removed out of the Kyphosichthyiformes and is recovered as the sister taxon of the Semionotiformes-Lepisosteiformes clade. The revised topology provides new insights into the anatomical evolution during the earliest ginglymodian history.
Key words   Luoping, Yunnan; Triassic; Kyphosichthyiformes, Ginglymodi; osteology; phylogeny