Abstract: A new species of sinamiid fish, Sinamia liaoningensis, is described from the Barremian-Aptian Yixian and Jiufotang formations of western Liaoning, China and the morphology of the sinamiid fishes is reviewed. The new materials reveal three synapomorphies of the Sinamiidae proposed by Grande and Bemis (1998): the presence of only a single median parietal; three pairs of extrascapular bones; and short dermopterotic about equal in length to parietal length. The new species was attributed to Sinamia because it has three synapomorphies of the genus: relative small postinfraorbitals, a long dorsal fin and rhombic scales. The new species is a big podgy fish and it differs from all other species of the genus in the shape of the rostral, nasal, preopercle, the size and shape of infraorbitals, more subinfraorbitals (3), less dorsal fin rays (18), more caudal fin rays (16), more scale rows (32) between the origin of the anal fin and the dorsal margin of the body, and lack of serrated scales. The anterior half of the caudal fin rays of S. liaoningensis sp. nov. has remains of thin fibrous actinotrichia.

摘要： 记述了辽宁西部九佛堂组和义县组中华弓鳍鱼一新种：辽宁中华弓鳍鱼Sinamia liaoningensis, 并与该属的其他种进行了比较。新材料具有中华弓鳍鱼科的3个定义特征：单一的顶骨，三对额外肩胛骨和膜质翼耳骨短并与顶骨等长，无疑应归入该科。新种的后眶下骨较小，背鳍长大，鳞片菱形，因此，归入中华弓鳍鱼属。辽宁中华弓鳍鱼在以下几个方面不同于中华弓鳍鱼的5个已知种：体型短粗，吻骨较短，鼻骨近四方形，围眶骨较多(6), 前鳃盖骨强烈弯曲，背鳍条较少(18), 尾鳍条较多(16), 臀鳍鳍基起点到鱼体背缘的鳞列较多(32), 鳞片后缘不具锯齿，尾鳍具有纤维状的角质鳍条。