中文摘要：

记述了云南曲靖地区早泥盆世洛霍考夫期华南鱼类一新属——王冠鱼（Stephaspis gen．nov．）。新属发现于西山村组下部致密坚硬的石英砂岩中，其主要特征是：个体较大的华南鱼类，头甲呈长盾形，后缘向后凸出；角发育，侧向延伸，末端向头甲后侧方自然倾斜，内角不发育；具吻突，但不甚发育；中背孔较大，呈纵向椭圆形，前端稍尖，后端圆钝；眶孔较小，圆形，背位；头甲背面具一对背窗，呈狭长椭圆形，靠近头甲侧缘；感觉管系统不甚发育，仅见后眶上管、侧背管、侧横管及背联络管，后眶上管呈V字形；纹饰为细小的粒状瘤点。新属不仅是华南鱼类在西山村组的首次发现，也指示了目前华南鱼类出现的最低层位，为探讨华南鱼类的起源与早期辐射提供了重要资料。

英文摘要：

A new genus of the family Huananaspidae （Galeaspida）, Stephaspis is described in this paper. Fossil materials were recovered from the Xishancun Formation （early Lochkovian, Devonian） of Qujing, Yunnan Province, China. The new genus is not only the first discovery of the Huananaspidae in the Xishancun Formation but also represents the earliest occurrence of the Huananaspidae in the Devonian to date. 1 Systematic paleontology Galeaspida Tarlo, 1967 Polybranchiaspidida Janvier, 1996 Huananaspidiformes Janvier, 1975 Family Huananaspidae Liu, 1973 Uenus Stephaspis gen. nov. Etymology From stephos （Gr.） = crown, diadem, in reference to the shape of headshield, and asp/s （ Gr. ） = shield. Type species Stephaspis dipteriga gen. et sp. nov. Diagnosis As for the type and only species, Stephaspis dipteriga gen. et sp. nov. Stephaspis dipteriga gen. et sp. nov. （Figs. 1 -3） From dipterigus = double wings or alae, in reference to two laterally projecting corners. Holotype An incomplete headshield （IVPP V 14333.1A, B）. Referred material An incomplete headshield （IVPP V 14333.2A, B）. Locality and horizon Qujing, Yunnan Province, southwestern China; Xishancun Formation （early Lochkovian, Devonian）. Diagnosis A large-sized huananaspidiform with a diadem-shaped headshield, longer than broad; posterior margin of headshield protruding backward; corner developed, projecting laterally and slanting backward to the caudal extremity; inner corner not developed; rostral process not very developed, slender at the base; median dorsal opening oval in outline with long axis aligned with the rostro-caudal axis and with a little pointed rostral extremity; orbital opening fairly small, round and dorsally placed on headshield, close to the mid-line of headshield; dorsal fenestra oval in outline and aligned with the rostro-caudal axis, dorsally placed and close to lateral margin of headshield ; sensory canal system poorly developed, V-shaped posterior supraorbital canal, lateral dorsa