由于埕北凹陷中生代地层的划分主要根据区域地质资料及部分孢粉化石,而白垩纪沉积缺乏充足的古生物资料,因此难以系统、准确地划分。在对埕北凹陷老斜452井的古生物分析中,发现穴状女星介(相似种)Cypridea(Cypridea)cf.cavernosa、蒙阴女星介C.(C.)mengyinensis等介形类化石,说明该地区存在白垩系,这一发现对该区中生代地层的划分提供了重要的古生物学依据。 Due to the division of the Mesozoic strata in the Tiebei depression, mainly based on regional geological data and some sporo-pollen fossils, Cretaceous sediments lack sufficient paleontological data and are therefore difficult to classify systematically and accurately. In the paleontological analysis of Well Xie 452 in the Chengbei depression, Cypridea (Cypridea) cf. cavernosa, C. mengyinensis and other mesogenic fossils were found, This shows that Cretaceous exists in this area, and this finding provides an important paleontological basis for the division of Mesozoic strata in this area.