We present the results of the quantitative and qualitative study of dinoflagellate cysts in outcrop samples from a section of the Snow Hill Island Formation (SHF) in James Ross Island, Antarctic. Dinoflagellate cysts assemblages are abundant and dominated by gonyaulacoid taxa. The last occurrence of the dinoflagellate cyst Kallosphaeridium? helbyi and Chatangiella granulifera, together with the first occurrence of Pterodinium cretaceum, indicates a probable late Campanian age (∼76.4–∼72.1 Ma) for the lower strata. Whereas the first occurrence of Manumiella bertodano and the last occurrence of Odontochitina operculata, Xenascus ceratioides, and Stiphrosphaeridium anthophorum indicate an early Maastrichtian (∼72.1–∼70.0 Ma) age for the upper strata. Our results, combined with paleobotanical and palynological published data, indicate medium–high continental and marine productivity with temperate paleoclimate free of glaciers for this interval. Lithological and paleontological data indicate mainly inner neritic marine depositional environments. The predominance of shales in the lower part of the lower Maastrichtian interval indicates a slightly deeper environment. In contrast, in the middle part of the lower Maastrichtian, a shallower, transitional environment is marked by the presence of theropod dinosaurs and decapod crustaceans.

我们介绍了南极詹姆斯罗斯岛雪山岛组 (SHF) 的一部分露头样品中甲藻包囊的定量和定性研究结果。甲藻囊肿组合丰富，以甲藻类群为主。最后一次出现甲藻囊肿Kallosphaeridium？helbyi和Chatangiella granulifera以及首次出现的Pterodinium cretaceum表明下层可能处于坎帕纪晚期（~76.4-~72.1 Ma）。鉴于Manumiella bertodano的第一次出现和Odontochitina operculata、Xenascus ceratioides和Stiphrosphaeridium anthophorum的最后一次出现表明上层的早期马斯特里赫特（~72.1-~70.0 Ma）年龄。我们的结果，结合古植物学和孢粉学已发表的数据，表明该区间的温带古气候没有冰川，大陆和海洋生产力处于中高水平。岩性和古生物资料表明主要是内浅海相沉积环境。下马斯特里赫特层段下部页岩的优势表明环境略深。相比之下，在下马斯特里赫特的中部，一个较浅的过渡环境以兽脚亚目恐龙和十足目甲壳类动物的存在为标志。