门: 节肢动物门
纲: 类肢纲
目: 未定
科: 未定
属: 小盾形虫
种: 达子小盾形虫
描述:
具有背腹扁平外骨骼的小型节肢动物，相对较宽。背侧外骨骼轴向区域界限不清，没有明显发育的轴沟。头甲短，覆盖宽大的口盖、单肢型触角和四对附肢。躯干由六个活动铰接的体节组成，每个体节具有一对附肢。尾甲近乎等尾，覆盖四对附肢和短小多节的尾刺。所有触角后附肢均为双肢型，由原肢、具有5个足节的内肢和外肢组成。
Phylum: Arthropoda
Class: Artiopoda
Order: uncertain
Family: uncertain
Genus：Pygmaclypeatus
Specie: daziensis
Description:
Small artiopod with dorsoventrally flattened exoskeleton, broader than long. Dorsal exoskeleton with poorly defined axial region without clearly developed axial furrows. Cephalon short, covering widely conterminant hypostome, uniramous antennae, and four appendage pairs. Trunk consists of six freely articulating tergites, each covering a single appendage pair. Pygidium nearly isopygous, covering four appendage pairs, and short multiarticulated tailspine. All post-antennal appendages biramous, consisting of protopodite, endopodite with five podomeres, and exopodite.
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
Schmidt M, Hou X, Zhai D, et al. Before trilobite legs: Pygmaclypeatus daziensis reconsidered and the ancestral appendicular organization of Cambrian artiopods[J]. Philosophical Transactions of the Royal Society B, 2022, 377(1847): 20210030.
Zhang X, Han J, Shu D. A new arthropod Pygmaclypeatus daziensis from the early Cambrian Chengjiang Lagerstätte, South China[J]. Journal of Paleontology, 2000, 74(5): 979-982.