基于在云南曲靖西山村组两个不同产地发现的新材料,对最大的真盔甲鱼类漫游憨鱼(Nochelaspis maeandrine)进行了再描述.憨鱼属(Nochelaspis)与同一层位产出的云南盔甲鱼属(Yunnanogaleaspis)最为相似,但与后者明显不同的是,憨鱼属具有裂隙形的中背孔(长与宽之比大于6),更强壮的内角,粗大的星状纹饰,以及具锯齿的中背孔和头甲边缘.漫游憨鱼的新材料提供了头甲腹面的关键形态学信息:口鳃窗被一个大的外骨骼腹片覆盖,该腹片上装饰着致密细小的瘤点,边缘排列有6对独立的圆形大鳃孔,这些鳃孔由腹片和腹环共同形成.盔甲鱼类的这种情况明显不同于骨甲鱼类,后者的口鳃窗被许多小嵌片或大一些的膜质小骨片覆盖,鳃孔呈裂隙状,并被小皮瓣覆盖,类似于现生的板鳃类.盔甲鱼类和骨甲鱼类的鳃孔与现生的鳐类一样,都开口于腹面,指示它们均为底栖鱼类,生活在具泥沙质基底的安静滨海环境中.“,”The new specimens of the largest eugaleaspiform Nochelaspis maeandrine are redescribed from two localities of the Xishancun Formation in Qujing City,Yunnan Province,southwestern China.Nochelaspis is most suggestive of Yunnanogaleaspis from the same horizon,but differs in its slit-like median dorsal opening(length/width＞6),much stronger inner cornual process,coarse stellate ornamentation,and the serrations along the edges of the median dorsal opening and headshield.The new findings reveal the morphological details on the ventral side of the headshield as well.The oralobranchial fenestra is covered by a large dermal ventral plate,which is decorated with dense,tiny granular tubercles,and aligned with six pairs of separated,large,and circular branchial openings.This condition is different from that of osteostracans,in which the oralobranchial fenestra is covered by numerous minute scales or larger dermal platelets,and the branchial openings are slit-shaped and covered by small skin flaps somewhat like those of elasmobranchs.However,the branchial openings of galeaspids and osteostracans are both located ventrally as in modern rays,indicating a benthic lifestyle dwelling on sandy or muddy substrates in a quiet marine environment.