寒武纪大爆发作为生物演化史上最为重要的演化创新事件，是古生物学研究的焦点与前沿领域。由于寒武系底部地层的缺失以及缺乏良好的化石记录，华北板块是寒武纪大爆发研究较为薄弱的地区；同时，华北板块寒武系底部地层时代及其在寒武纪早期的古地理位置一直都颇具争议。多门类骨骼化石（“小壳化石”）不仅是研究寒武纪大爆发、划分对比寒武纪早期地层的关键化石，还可为重建寒武纪早期古生物地理提供重要依据。华北板块南缘与东南缘寒武系底部产有丰富的小壳化石，但一直以来都缺乏详细的研究。本项目拟对华北板块南缘与东南缘寒武系底部辛集组与猴家山组小壳化石开展详细的系统古生物学、生物地层学以及定量古生物地理研究，较为全面地恢复这套小壳化石的组合面貌，并限定其所属时代与古生物地理分区，从而进一步限定华北板块寒武系底部地层时代以及华北板块在寒武纪早期的古地理位置，探讨寒武纪大爆发在华北板块的表现特征。

As a major biotic evolutionary innovation in the earth history, Cambrian Explosion is one of the hottest research fields in palaeobiology. However, for the lack of the basal Cambrian strata and fossil records, the feature of Cambrian Explosion is still poorly known for North China Plate (NPC). In addition, the age of the basal Cambrian strata of NPC and its palaeogeographical position are still quite controversial. The Small shelly fossils (SSFs), including multiple metazoan phyla, are significant fossil records to study the Cambrian Explosion. SSFs are also very useful in the early Cambrian (Terreneuvian and Epoch 2) biostratigraphical correlations and palaeobiogeographical reconstruction. Although SSFs have been widely discovered from the basal Cambrian Xinji and Houjiashan formations (Cambrian Series 2) along the southern and southeastern margin of NCP, they are still poorly studied and need more comprehensive researches. Hence, this project will focus on the detailed systematic palaeontology, biostratigraphy and quantitative palaeobiogeography of the SSFs from the Xinji and Houjiashan formations, which can be useful for the further constraint on the age of the basal Cambrian strata as well as the palaeogeographical position of NPC during the early Cambrian. Meanwhile, this work will provide sufficient fossil evidence to explore the evolution of SSFs during Cambrian Epoch 2 and to study the scale and pattern of Cambrian Explosion in NPC.