Cretaceous algal palynomorphs from northeast Sinai, Egypt: systematics and paleoenvironmental implications

Abstract

T HE microalgal palynomorphs considered one of the main categories of non-pollen palynomorphs recognized in palynological slides which characterized by their potential paleoecological and stratigraphical values especially in the pre-Quaternary deposits. For this importance, four subsurface cutting samples recovered from two Cretaceous (Aptian/Albian and Turonian) geological units in Bougaz-1 well, northeast Sinai have been palynologically analyzed in order to study their algal content. Seven species of algae related to four genera from two divisions have been described and illustrated: Pediastrum boryanum, P. duplex, P. kawraiskyi, P. simplex, Scenedesmus acuminatus, and Chomotriletes minor (Chlorophyta); and Pterospermella sp. (Prasinophyta). Of these, two species (Pediastrum kawraiskyi and Scenedesmus acuminatus) are recorded for the first time from the Cretaceous of Egypt. Notes on the stratigraphic range and the geographical distribution of the most important recorded genera are given. The cell wall nature and its role in resistance to degradation are also discussed. The ecology of extant taxa has been used to determine the paleoenvironment and paleoecology prevailed in the studied area during the Cretaceous period.

Reconstruction of paleovegetation and paleoecology from the Early Cretaceous sporomorphs of Bougaz-1 well, northeast Sinai, Egypt

“…This paper is a continuation of the study of the terrestrial palynomorphs from the Cretaceous sequence in Bougaz-1 well, northeast Sinai (El Noamani & Saleh, 2018). The latter work was restricted to the algal palynomorphs and excluded the diverse pollen and spores assemblage studied in the present work.…”

First Tithonian Record of Perforated Pediastrum Meyen S.L. Species Within Early–diagenetic Carbonate Concretions From the Vaca Muerta Formation, Neuquén Basin, Argentina. Implications for the Palynological Analysis of Fine-Grained Rocks

“…Pediastrum simplex is recorded worldwide since the Late Triassic (Nader & Kddo, 2018), but the most abundant registers come from Cretaceous to Cenozoic deposits (e.g., Songtham et al, 2003;Sha, 2007;El-Noamani & Saleh, 2018). In southern South America, the oldest previous record of this taxon comes from the Late Miocene of the Calchaquí Valley, Salta Province (Starck & Anzótegui, 2001).…”

“…clathratum is a scarcely registered species in the fossil record. This taxon was identified in the Neogene deposits of China as P. clathratum (El-Noamani & Saleh, 2018). In Argentina, it was only recognized in modern lakes of the Mesopotamia region (Tell, 2004) microscopy, the joining of each cell with its neighboring cells shows a stronger and more brightened fluorescence in yellow color than the rest of the coenobium (Fig.…”

Dietary microalgal-fabricated selenium nanoparticles improve Nile tilapia biochemical indices, immune-related gene expression, and intestinal immunity

“…In this context, members of the genus Pediastrum (Sphaeropleales, Hydrodictyaceae), unicellular and colonial chlorophytes, are promising microalgae for biotechnological, food, industrial, and pharmaceutical applications [ 21 , 22 ]. The most widely distributed species in eutrophic freshwater and sediments from the Cretaceous of Egypt is Pediastrum boryanum ( P. boryanum, Turpin) [ 23 ]. The green microalga P. boryanum produces higher levels of secondary metabolites, such as carotenoids, polyunsaturated fatty acids, vitamins, carotenoid pigments, and polyphenols, demonstrating a notable inhibitory effect on lipid peroxidation [ 24 ].…”