门: 脊索动物门
纲: 无颌总纲
目: 未定
科: 未定
属: 海口鱼属
种: 耳材村海口鱼
描述:
整体呈纺锤形，比昆明鱼更细长，分为头部和躯干两部分。身体前端具有呈放射状的背鳍。头部具有至少六对，可能多达九对的鳃弓。身体具有肌节。
Phylum: Chordata Haeckel,1874
Class: Agnatha Cope, 1889
Order: unknown
Family: unknown
Genus：Haikouichthys Luo et al., 1999
Specie: Haikouichthys ercaicunensis Luo et al., 1999
Description:
Fusiform, more slender than Myllokunmingia, divided into head region and trunk. Prominent dorsal fin towards anterior, with fin-radials. Head bears at least six, possibly up to nine, gill arches. Trunk with myomeres.
时代：寒武系第二统第三阶
主要产地: 中国昆明海口镇
Age: Cambrian Series 2 Stage 3
Principal localities: Haikou, Kunming, China
Shu, D.G. et al. 1999. Lower Cambrian vertebrates from south China. Nature, 402(6757), 42–46.
Zhang, X.L., Hou X.G. 2004. Evidence for a single median fin-fold and tail in the Lower Cambrian vertebrate, Haikouichthys ercaicunensis. Journal of Evolutionary Biology, 17(5), 1162–1166.