The Spratly Islands are located in a vast area with numerous coral reefs in the South China Sea within the highly biodiverse Indo-Pacific region. Benthic foraminifera were investigated from two unstudied, remote atolls: Louisa Reef (LR) and Royal Charlotte Reef (RC). These atolls are about 250 kilometers off Brunei Darussalam, situated at the northern coastline of Borneo. We compare diversity and distribution of the benthic foraminifera from these atolls with those reported from shallow water setting in Brunei. Environmental conditions nearshore Brunei is very different due to strong influence of riverine runoff resulting in eutrophic and siliciclastic conditions, whereas the atolls are oligotrophic, and carbonate dominated. The composition and diversity of larger benthic foraminifera (LBF) clearly reflects such environmental differences. The most common species of LBF in the atolls are Calcarina defrancei, C. hispida, Amphistegina lobifera, A. radiata, Amphisorus hemprichii, and Parasorites orbitolitoides. The smaller benthic foraminifera are less abundant and much less species were recovered, still there are common taxa such as Tretomphaloides concinnus and Textularia agglutinans. The soritids, are common in the carbonate atolls, but are very rare in the nearshore Brunei: in fact, only the species Amphisorus hemprichii was found in two shallow reefs so far (Telesai and Hornet reefs, western part of Brunei coast). The results obtained also indicate that the dominant LBF species found in the atolls show different depth distribution with respect to the nearshore species. Despite the two atolls are characterized by comparable environmental conditions and are 70 kilometers apart, data show several differences in the benthic foraminifera community structure. By comparing data from the two atolls and the nearshore Brunei fauna, we can draw attention to the questions of LBF migration patterns and strategies that are here discussed: the interpretation points to a species-specific adaptation capacity probably resulting from different colonization events over time.

A significant portion of the upper Eocene deposits in southern Iran primarily consists of limestones, forming what is known as the Jahrum Formation. This formation serves as a reservoir rock in the Zagros Basin, containing numerous hydrocarbon-bearing intervals. The benthic foraminifera are valuable indicators for controlling facies and are abundant in the Jahrum deposits. In this study, by investigating a total of 344.5 meters of the Jahrum succession in the studied well, the distribution of various skeletal grains including benthic foraminifera, algae, bryozoans, and echinoid fragments was determined. The results revealed that the depositional environment of the Jahrum Formation is a homoclinal ramp with three distinct facies belts: lagoon, shoals, and open marine. In addition, within these paleoenvironments the discernible presence of the family Nummulitidae is significant. The nummulitid genera with flattened tests in association with red algae, echinoids, and bryozoans belong to the open marine environment with normal salinity. On the other hand, the miliolids with packstone to grainstone texture formed the shoals, and the absence of nummulitids and the abundance of porcelaneous foraminifera suggest a lagoonal environment with high salinity. Facies analysis has led to the recognition of four depositional sequences, confirming the age of the formation as Priabonian. Finally, considering the biotic relationship among three groups of taxa—algae, bryozoans, and echinoids—with Nummulitidae, Hauerinidae, Rotalidae, and Soritacea (Peneroplidae and Soritidae), their morphological features, and relative distribution, we construct a paleoenvironmental model for the upper Eocene.

The name of the genus of the larger foraminifera Alexina Hottinger and Caus 2009 is preoccupied by the insect genus name Alexina Edwards 1929 and is replaced here by Alexnoguesina nom. nov. in accordance with Article 52.1 (principle of homonymy) and Article 60.3 (junior homonyms without synonyms) of the International Code of Zoological Nomenclature.

Marine microfossil records from the Arabian Sea (AS) are mainly limited to foraminifera, with scanty information on other phyto- and zoo-plankton remains. Calcareous dinoflagellate cysts are one of the rarely studied microfossil groups across the world. In the present study, a calcareous dinoflagellate cyst (dinocyst) record from the eastern Arabian Sea (Off-Goa (SC-26)) during the Holocene is presented. Coccoides (vegetative stage of calcareous dinoflagellates) of Thoracosphaera heimii, Leonella granifera shows a dominance of 82–92% of the total assemblage suggesting a eutrophic environment throughout the studied period. The relative percentage of the dominant species T. heimii and L. granifera shows an opposite trend. The high relative abundance of Calciodinellum species during the early Holocene (prior to 10 ka BP) indicates a comparatively warm and low productivity environment compared with the late Holocene. A strengthening trend in the monsoon during the Holocene since 10 ka BP is reflected by the gradual increase in L. granifera, which is a runoff/terrestrial nutrient indicator. The high relative abundance of L. granifera, eutrophic taxa, and TOC since 6 ka BP reveals high primary productivity during middle to late Holocene compared with the early Holocene in the eastern Arabian Sea. Sand % which reflects runoff and L. granifera records show high similarity revealing that L. granifera % can be used as a terrestrial nutrient indicator, which has been suggested previously in studies from the Mediterranean Sea and South Atlantic. This record reveals the potential of calcareous dinoflagellate cysts to reconstruct monsoon variation, particularly runoff changes, in the Arabian Sea.

Enigmatic, thick-walled, agglutinated microfossils are described for the first time from the Middle Miocene of Austria. The microfossils are documented in large numbers from the Oberpullendorf Basin in Austria, where they occur in intertidal mudflat deposits associated with an oyster biostrome and in close vicinity to stromatolites. The basin was part of the epicontinental Central Paratethys Sea and was covered by a warm, restricted, hypersaline lagoon, which formed during the Badenian Salinity Crisis at roughly 13.8–13.6 Ma. Widespread evaporite formation characterized the Central Paratethys Sea at that time. Micro-CT scans of the structures reveal morphological features, which suggests that the fossils are rhizoliths, most likely from the rhizolith type 1. The fossils were probably formed by halophilic grasses, or herbaceous plants. The rhizoliths are strikingly similar to agglutinated foraminifera of the family Astrorhizidae and could easily be confused with foraminifera. Extant Astrorhizidae, however, are typically found in offshore deep-sea environments, which is in strong contrast to the ecological requirements of the Miocene Ritzing microfossils. Therefore, despite the morphological similarities, a relation with Astrorhizidae is excluded. We provide the first detailed morphologic description of fossil rhizoliths from a hypersaline lagoon and assume that they might represent an overlooked feature in coastal deposits of the Proto-Mediterranean Sea and the Paratethys region.

A new genus, Bolivilongella n.gen, and two new species belonging to the family Bolivinoididae are described from the Miocene of the Mango-2 well, Mediterranean Sea, Egypt. A comparison is made between other genera such as Bolivina, Bolivinoides, Bolivinella and Bolivinita that display some degree of similarity. Based on the specific characters, two new species: Bolivilongella longata n.sp. of Langhian age, and Bolivilongella semilongata n.sp. of Burdigalian age are here described.

This work presents a taxonomic study on the ostracods recovered from sediment samples collected in the Northeastern Atlantic and Western Mediterranean by French scientific expeditions carried out by the Travailleur and Talisman ships in the late 19th century. The samples deposited in the collections of the Muséum national d’Histoire naturelle in Paris have not been studied for ostracods since the works of G. S. Brady between 1884 and 1887. Fifty-three species distributed among 28 genera and 12 families are reported, characterizing typical deep-sea faunas. A neotype is proposed for Buntonia radiatopora (Seguenza) and its diagnosis is emended.

We present here the analysis of planktonic foraminiferal assemblages from two stratigraphic sections cropping out at the Podstine and at Zarace coves, at Hvar Island (Croatia), recording the flysch sediments in the Dinaric foreland basin during the late Eocene. The planktonic foraminiferal biostratigraphy reveals a Priabonian age of the sediments analyzed (Biozone E15 in Podstine cove section and Biozones E15 and E16 in Zarace cove section). We focus on the small-sized, planispirally–coiled Pseudohastigerina micra (Cole 1927) providing several morphometric measurements on specimens. The test diameter of P. micra tests reveals a decrease during the Biozone E15 as observed at the Podstine cove section, with stabilization at such smaller test sizes observed in Biozone E16 at the Zarace cove section. We attribute this size decrease as mainly due to the global sea surface cooling occurring during the late Eocene and possibly to enhanced surface water eutrophication. The cooling trend is supported by the increase in relative abundances of planktonic foraminifera cold-water taxa recorded in the assemblages whereas increased eutrophication appears largely controlled by nutrient input due to enhanced weathering, as suggested by lithological changes. Superimposed to the test-size decrease, the degree of test compression (ratio of test diameter and width) in P. micra proves to change irregularly, indicating intervals of ecological instability. The variations in abundance of P. micra, in phase with the genus Globoturborotalita, known to inhabit the surface water layers, suggest a similar habitat for P. micra for which the late Eocene paleoecology was uncertain.