门: 节肢动物门
纲: 类肢纲
目: 未定
科: 海怪虫科
属: 海怪虫属
种: 镜眼海怪虫
描述:
镜眼海怪虫的外骨骼未矿化，通常保存为压平的背甲。完整个体长度大于 5 厘米。
镜眼海怪虫拥有一个较大的半椭圆头甲，向后延伸覆盖躯干前端。覆盖处轴部有一个较小的体节。头部有六对双肢型附肢，位于长长的多环状触角后面，触角从头甲前端伸出。一对复眼，具有眼柄，从腹面伸出，透过背侧一轮圆形凸起的外骨骼进行观察。每只眼睛处向侧边延申出一条裂缝, 这个特征与三叶虫的面线类似。轴部小体节后是具有11个体节，躯干末端体节具有轴刺。双足附肢由具有许多足节组成。
镜眼海怪虫仅见于云南省下寒武统地层。
Phylum: Arthropoda
Class: Artiopoda
Order: uncertain
Family: Xandarellida
Genus: Xandarella
Specie: spectaculum
Description:
The exoskeleton of Xandarella spectaculum was unmineralized and is typically preserved dorsoventrally flattened. Complete specimens are greater than 5 cm long.
X. spectaculum possesses a large semi‐elliptical head shield that is extended posteriorly to overlap the anterior part of the trunk, where there is a small axial tergite. The head has six pairs of biramous appendages behind the long multi‐annulate antennae that protrude beyond the anterior end of the head shield. Paired compound eyes are stalked, based ventrally. The eyes are configured to see through a round, raised exoskeleton bulge in the dorsal part of the exoskeleton. A fissure extends from each eye to the lateral margin of the head shield, this feature is reminiscent of the dorsal facial suture in trilobites. Behind the small axial tergite are a further 11 tergites, the trunk being terminated by an axial spine arising from the terminal tergite. The biramous appendages consist of an endopod with many podomeres.
X. spectaculum is known only from lower Cambrian strata of Yunnan Province.
时代: 寒武系第二统第三阶
主要产地: 澄江生物群，中国，云南
Age: Cambrian Series 2 Stage 3
Principal localities: Chengjiang biota, Yunnan, China
Xian-Guang H, Siveter D J, Siveter D J, et al. The Cambrian fossils of Chengjiang, China: The flowering of early animal life[M]. John Wiley & Sons, 2017.
Ortega-Hernández J, Azizi A, Hearing T W, et al. A xandarellid artiopodan from Morocco–a middle Cambrian link between soft-bodied euarthropod communities in North Africa and South China[J]. Scientific Reports, 2017, 7(1): 1-16.
Chen X, Ortega-Hernández J, Wolfe J M, et al. The appendicular morphology of Sinoburius lunaris and the evolution of the artiopodan clade Xandarellida (Euarthropoda, early Cambrian) from South China[J]. BMC evolutionary biology, 2019, 19(1): 1-20.