贵州独山泥盆纪胴甲鱼类一新属

摘要

胴甲鱼类为世界性分布的古生代鱼类,其化石是确定泥盆纪地层时代及地层对比的重要标志之一.本文记述了胴甲鱼类一新属、新种——张氏猴儿山鱼Houershanaspis zhangi gen.et sp.nov.,其前中背片外形和与周边甲片的覆压关系类似于沟鳞鱼类,但甲片表面具有独特的条纹状纹饰,可区别于其他胴甲鱼类.这一化石发现于贵州省独山县城以东的猴儿山,产出层位为早泥盆世丹林组下部,约相当于布拉格期(Pragian)晚期.%The fossil discovered in the Early Devonian strata of Dushan in 1963 has been referred as "Houershanolepis changi" in several articles,but neither diagnosis nor description was provided,so the "Houershanolepis changi " has become a nomen dubium.Here a new antiarch (placoderm) fish Houershanaspis zhangi gen.et sp.nov.,is erected based on the fossil materials discovered from Early Devonian Danlin Formation in Mt.Houershan,Dushan County of Guizhou Province,Southwest China,which is different from other antiarch fishes in its long ridge ornamentation and its bothriolepid-like anterior median dorsal plate.The diagnosis of this fish is as follows:small antiarch fishes;the anterior median dorsal plate (AMD) is longer than its breadth with a wide anterior margin which is nearly equal to its posterior margin;the levator fossa is short and the post levator fossa is present;the anterior ventral pit is located at the anterior 1/5 of the AMD length;the overlap relationship between the AMD and neighboring plates is similar to that of Bothriolepis,and the ornamentation is mainly composed of regularly displayed long ridges.