新疆塔里木盆地志留纪盔甲鱼类新知

A reappraisal of the Silurian galeaspids(stem-Gnathostomata) from Tarim Basin, Xinjiang

通过对新疆塔里木盆地志留系新一轮野外考察和对原来塔里木志留纪盔甲鱼类再观察,取得了以下认识:1)依据新增加的材料,张氏南疆鱼(Nanjiangaspis zhangi)被厘定为一新属西域鱼(Xiyuaspis),并确定其系统位置隶属修水鱼科(Xiushuiaspidae);2)潘氏小瘤鱼(Microphymaspis pani)曾被归于Xiushuiaspidae,系缘于观察上的失误,通过再观察得出M.pani当属大庸鱼科(Dayongaspidae),同时与其产于同一产地和层位的天山宽头鱼(Platycaraspis tianshanensis)系前者的同物异名;3)经重新研究,产于柯坪克兹尔塔格组曾被视为节甲鱼类的标本实属盔甲鱼类,并被鉴定为一新的属种:残缺角鱼(Jiaoyu imperfectus);4)产于柯坪塔塔埃尔塔格组的汉阳鱼未定种(Hanyangaspis sp.)的前腹片和产于柯坪塔塔埃尔塔格组及巴楚依木干他乌组的锅顶山汉阳鱼(H.guodingshanensis)具雪花状纹饰的骨片,可能均属柯坪南疆鱼(Nanjiangaspis kelpinensis);5)根据所产盔甲鱼残缺角鱼(J.imperfectus),将克兹尔塔格组的时代修订为早泥盆世。

Summary Some new galeaspid specimens have been recently found from the Silurian of Tarim Basin,Xinjiang.The description of these specimens and the new examination of the galeaspid collections render us the following understanding on the morphology and taxonomy of the Silurian galeaspids from Xinjiang.1)Nanjiangaspis zhangi is removed from the Hanyangaspidae,and referred to a new genus of the Xiushuiaspidae,Xiyuaspis gen.nov.;2)Platycaraspis tianshanensis is the junior synonym of Microphymaspis pani.According to the principle of priority,Microphymaspis pani is retained,but it is removed from the Xiushuiaspidae,and referred to the Dayongaspidae.