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A systematic review of Paleogene agglutinated foraminifera with internal structures (subfamily Pavonitininae) from the Eocene of northwestern Saudi Arabia

Korin Asmaa, Allam Sherif, Prayudi Sinatrya D., Zalmout Iyad S., Memesh Abdullah, Alnajjar Mohammed I., Bahameem Ahmed A., Kaminski Michael A.

Annales Societatis Geologorum Poloniae

2025

Vol. 95, No. 2

141--152

Agglutinated foraminifera with complex internal structures represent key components of deep-marine benthic assemblages and are important tools for biostratigraphic and palaeoenvironmental reconstructions. The subfamily Pavonitininae, which includes the genera Pavonitina and Pavopsammia, previously has been documented mainly from Oligocene to Miocene successions of the central Paratethys, West Africa, and the Atlantic margins. This study reports the first stratigraphically well-constrained record of Pavonitininae from the upper Eocene (Biozone E14) Rashrashiyah Formation in the Sirhan-Turayf Basin of northwestern Saudi Arabia. The recovered assemblage includes Pavopsammia flabellum, Pavonitina styriaca, Pavonitina biarritzensis, and Pavonitina kiscelliana. The morphological characteristics of these species, preserved in marly limestones and calcareous claystones, show transitions from an initially coiled arrangement to biserial and uniserial arrangements, reflecting different evolutionary phases of the group. Their co-occurrence extends their known stratigraphic range into the Priabonian and shows that important morphological modifications emerged earlier than previously thought, providing the oldest reliably dated record of the Pavonitininae. Palaeoceanographic changes, such as carbonate compensation depth deepening and oxygen minimum zone expansion, along with the Sirhan-Turayf Basin’s palaeogeographic location along the southern Tethyan margin, probably encouraged diversification of the Pavonitininae and their dispersal towards the Paratethys and Atlantic Ocean. These findings refine the evolutionary history, palaeobiogeography, and palaeoecological significance of the Pavonitininae, and improve their application in biostratigraphic and palaeoenvironmental studies of Paleogene deep-marine deposits.

Foraminiferal stratigraphy of Palaeogene deep-water red facies in the Gorce Mountains (Magura Nappe, Polish Outer Carpathians)

Bąk K., Bąk M., Cieśla M., Paul Z.

Annales Societatis Geologorum Poloniae

2013

Vol. 83, No. 3

201--212

The deposition of red and variegated mudstones and claystones characterized the ancient Tethys Ocean during Cretaceous and Palaeogene times, including in its north-western part, the Alpine–Carpathian deep-water basins. Palaeogene variegated sediments, containing red mudstone and claystone layers, crop out in the Gorce Mountains (Rosocha creek, near Lubomierz) in the Magura Nappe (Bystrica Subunit) of the Polish Outer Carpathians. These sediments occur as layers 1–10 cm thick and as packages of layers 2–3 m thick that are associated with very thin-bedded turbidites. The entire succession is tectonically disturbed and parts of it belong to the Ropianka, Łabowa Shale and Beloveža Formations. The sediments studied contain 27 genera and 59 species that belong to deep-water agglutinated foraminiferal (DWAF) assemblages. Tubular taxa, which are frequent in various Mesozoic–Cenozoic flysch sediments are relatively rare in the section studied. The assemblages are moderately diverse (3–20 taxa per sample). Excluding tubular forms, the most common taxa belong to Trochamminoides – Paratrochamminoides spp., Saccammina placenta, glomospirids, Recurvoides – Recurvoidella spp. and karrerulinids. The oldest part of the red sediments, referable to the Ropianka Formation, represents the upper part of the Rzehakina fissistomata Zone (probably the Upper Palaeocene). The youngest red sediments, forming thin intercalations in the Beloveža Formation, represent the acme of Reticulophragmium amplectens (middle Lutetian). Owing to tectonic disturbances, most of the Lower Eocene part of the variegated facies of the Łabowa Shale Formation is not preserved in the section studied. The upper part of it, a package 2 m thick, represents the lower part of the Reticulophragmium amplectens Zone. The small thickness (10–15 m) of the Łabowa Shale Formation in the section studied is similar to other sections in the southern part of the Bystrica Subunit. It is probably of a sedimentary nature, reflecting a decreasing number of mud-rich, gravitational flows in the southern part of the Magura Basin during the Early Eocene. Nevertheless, the strong tectonic disturbances that took place in this area during the Oligocene–Miocene folding and overthrusting influenced the reduction in thickness of these sediments.

A new species of primitive Reticulophragmium (Foraminifera) from the Paleocene Vidono Formation of northeastern Venezuela

Kaminski M. A., Crespo de Cabrera S.

Annales Societatis Geologorum Poloniae

1999

Vol. 69, No. 3-4

189-193

The new species Reticulophragmium vidonioensis Kaminski & Crespo de Cabrera is newly described from the subsurface Vidono Formation of northeastern Venezuela. The foraminiferal assemblage is dated as Zone P3 (mid Paleocene), and represents an outer neritic-upper bathyal biofacies. Reticulophragmium vidonioensis n.sp. displays very primitive morphological features, and illustrates the close evolutionary relationship between the earliest Paleocene alveolar genus Reticulophragmium and the non-alveolar genus Haplophragmoides.

Z osadów środkowego paleocenu (zona P3) formacji Vidono w północno-wschodniej Wenezueli opisano nowy gatunek Reticulophragmium vidonioensis Kaminski & Crespo de Cabrera, należący do grupy otwornic aglutynujących. Zespół otwornic z nowo opisanym taksonem reprezentuje biofacje z pogranicza strefy nerytycznej i górnego batiału. Gatunek Reticulophragmium vidonioensis n.sp. charakteryzują cechy stawiające go jako forme pośrednią pomiędzy rodzajem Reticulophragmium o alweolarnej strukturze i rodzajem Haplophragmoides nie wykazującym w budowie wewnętrznej skorupki struktury alweolarnej.