Abstract: The fossil fish described here was collected from the Yan' an Formation (Middle Jurassic) of Ningxia, and is referred to a new species, P. ningxiaensis, of the Genus Palaeoniscinotus. It resembles Palaeoniscinotus czekanowskii in many respects, but is characterized by its fewer fin—rays of the dorsal and anal fins, oblique enamelled striae on the scales, and fewer scales of the lateral line etc. Previously Palaeoniscinotus was known only from Siberia, Russia, this new discovery is of great significance to the study of the biostratigraphy in Liupanshan Basin.

摘要： 记述了在宁夏六盘山盆地侏罗系中发现的古背鳕(Palaeoniscinotus)一新种—宁夏古背鳕(P. ningxiaensis)。其一般形态特征如体形、鳍的位置和结构、悬挂骨的倾斜程度、鳃盖骨系统及鳞片等结构，与俄罗斯伊尔库茨克中侏罗世的切卡诺夫斯基氏古背鳝(P.czekanowskii)很相似，但新种的背鳍和臀鳍的鳍条均较少、鳞片条纹倾斜分布以及侧线鳞较少等特征显然有别于后者。最后讨论了这个属的系统位置和含鱼化石地层的时代，认为属中侏罗世的可能性较大。