Samir Ahmed, Moneer El Sayed M, El-Sheikh Islam, Bazeen Youssef S
Geology Department, Faculty of Science, Al-Azhar University, PO. Box: 11884, Cairo, Egypt.
Geology Department, Faculty of Science, Al-Azhar University, Assiut Branch, PO. Box: 71524, Assiut, Egypt.
Sci Rep. 2025 Feb 25;15(1):6828. doi: 10.1038/s41598-025-89560-6.
This study investigates ostracod faunas from the well-preserved Paleocene to lower Eocene sedimentary succession at Wadi Tarfa, North Eastern Desert, Egypt. A total of 22 species and subspecies across 16 genera and 8 families were identified across 57 samples. Three zones were identified: Doricythereis jordanica jordanica Zone, Cytheropteron toshkaensis Zone, and Phalcocythere horraensis Zone, based on the stratigraphic distribution of ostracod fauna. However, correlations with other sections revealed inconsistencies in the first and last occurrences of ostracod species, indicating complexities in regional biostratigraphic correlation by ostracod fauna and the influence of localized depositional factors. Both R-mode and Q-mode clustering analyses were applied to ostracod assemblages, identifying four distinct faunal clusters and five biofacies, reflecting depositional changes from outer neritic to upper bathyal environments. The late Paleocene revealed reduced ostracod diversity, correlating with a deepening marine environment, particularly in the Tarawan Formation. Non-Metric Multidimensional Scaling (NMDS) analyses indicated significant paleobiogeographic connections between North African and Levantine sites, while faunal differentiation was greater in West African and Middle Eastern regions due to marine barriers.
本研究调查了埃及东北沙漠瓦迪塔尔法保存完好的古新世至始新世早期沉积序列中的介形虫动物群。在57个样本中，共鉴定出16属8科的22个物种和亚种。根据介形虫动物群的地层分布，确定了三个带：约旦多里西介约旦亚种带、托什卡西翼介带和霍拉法尔科介带。然而，与其他剖面的对比显示，介形虫物种的首次和末次出现存在不一致，这表明介形虫动物群在区域生物地层对比中存在复杂性，以及局部沉积因素的影响。对介形虫组合进行了R型和Q型聚类分析，确定了四个不同的动物群聚类和五个生物相区，反映了从外浅海到上半深海环境的沉积变化。晚古新世介形虫多样性降低，这与海洋环境加深有关，特别是在塔拉万组。非度量多维标度分析（NMDS）表明，北非和黎凡特地区之间存在显著的古生物地理联系，而由于海洋屏障，西非和中东地区的动物群分化更大。
