Search

Megalolamna is an extinct lamniform shark genus that is known from Miocene marine deposits. In this study, three new specimens of Megalolamna collected from the eastern USA are newly described, and the diagnosis of the genus is emended to include a previously undocumented dental characteristic. The new specimens are represented by one tooth from the upper Oligocene Chandler Bridge Formation in South Carolina and two isolated teeth from the lower Miocene Calvert Formation in Maryland. The specimens from the Calvert Formation represent the northern-most occurrence of Megalolamna. Although the taxonomic identification of the specimen from the Chandler Bridge Formation is somewhat tentative, it is considered to represent geologically the oldest record of Megalolamna, suggesting the likelihood that the enigmatic genus has its origin in the Palaeogene no later than 23.5 Ma. [ABSTRACT FROM AUTHOR]

A new species Theronia qaidamensis sp. nov. (Ichneumonidae, Pimplinae) is described from the Oligocene Shangganchaigou Formation of the northwestern Qaidam Basin (Huatugou area), northeast of the Tibetan Plateau (TP). The new species represents the first report of the Ichneumonidae from the Qaidam Basin, which reveals an insect linkage between the Qaidam Basin and Europe. In addition, the study of associated fossils from the Shangganchaigou Formation shows that the palaeoenvironment of the northwestern Qaidam Basin during the Oligocene was warm and moist, which provided suitable living conditions for the current fossil. [ABSTRACT FROM AUTHOR]

Anomaluroid rodents (i.e. Anomaluridae + Zenkerellidae) have a long evolutionary history in Africa dating back to at least the middle Eocene, but Palaeogene fossil members of the anomaluroid crown group have never been found south of the Sahara. Here, we describe the oldest crown anomaluroid from sub-Saharan Africa, Eliwourus topernawiensis (new genus and species) from the early Oligocene Topernawi Formation of northern Kenya. Bayesian phylogenetic tip-dating analysis of a combined molecular-morphological dataset places ~29.5 Ma Eliwourus as an advanced stem anomalurid, and suggests that crown Anomaluridae originated ~28.2 Ma. The gliding behaviour seen in all crown anomalurids had, therefore, likely evolved before the close of the early Oligocene. Bayesian geocoordinates analysis places the origin of crown Anomaluroidea (~47.2 Ma) in northern Africa, and identifies a stem anomalurid dispersal into equatorial eastern Africa in the latest Eocene or earliest Oligocene. We present the first quantitative analysis of the pace of anomaluroid dental evolution and confirm a remarkably slow or bradytelic rate of phenotypic change, despite significant transformations in postcranial morphology related to the evolution of gliding behaviour during the same interval. The Topernawi area was evidently sufficiently forested during the early Oligocene to support both arboreal rodents and primates. [ABSTRACT FROM AUTHOR]

The Jiaozigou Formation, the lowest fossiliferous stratum in the Linxia Basin, produces the most abundant mammalian fossils in East Asia. Although the Jiaozigou Fauna is renowned for the ‘giant rhino’ (Paraceratheriidae), evidence of relatively small rhinocerotoids is scant, consisting only of fragments. The newly identified species, Megacanodon dongxiangense gen. et sp. nov. is characterised by its small-sized body, the presence of a large canine, nearly completely molarised upper premolars, retracted nasal notch, and not-elevated occipital part. It remains unclear whether the new genus is phylogenetically close to Hyracodontidae, Eggysodontidae, or Rhinocerotidae. We tentatively designate it as a basal genus within Rhinocerotoidea, with the uncertain family affiliation. [ABSTRACT FROM AUTHOR]

Kuphus is a genus of teredinid bivalves whose modern counterpart, K. polythalamius, colonises oxygen-poor and restricted marine environments enriched in plant remains. In the Oligocene, Kuphus colonies are quite abundant worldwide, but their depositional setting has never been studied in detail. We describe the first report of Oligocene Kuphus beds from the Iberian Peninsula, cropping out in platform deposits of the Prebetic (Southeastern Spain). By means of anterior endings and taphonomic characters as orientation of Kuphus tubes, fragmentation, packing and mixing with other fauna, four skeletal concentrations were distinguished: SkC A represents in situ colonies with anterior endings well preserved and with local dolomitisation around the tubes and was recorded in the inner lagoon; SkC B, with parallel and horizontally reoriented tubes, was formed by tidal currents; SkC C records high-energy events breaking down the tubes and resedimenting them close to the source area; SkC D is characterised by fragmented tubes mixed with other bioclasts, deposited by storms in the outer platform. The recorded skeletal concentrations are consistent with the environmental setting of K. polythalamius, but the morphological differences and the absence of data on the presence of plant remains could possibly reflect adaptations to higher variety of palaeoenvironments. [ABSTRACT FROM AUTHOR]

The wood anatomy of Paradiospyroxylon kvacekii gen. et sp. nov. is described and illustrated based on material originating from the Ústí Formation's volcanic deposits of České středohoří Mts. (Paleogene, Czech Republic). The sample, identified earlier as Manilkaroxylon sp., was critically examined and is interpreted as root wood and proposed as the paratype of Paradiospyroxylon kvacekii. This paper discusses how wood anatomical variation needs to be considered when making systematic and palaeoecological interpretations. [ABSTRACT FROM AUTHOR]

Aplodinotus grunniens represents one of the most common, widespread, and unique freshwater fishes in North America. Understanding the evolutionary history of this sciaenid is challenging though as published palaeontological records are lacking. Existing literature documenting skeletal remains and otoliths is summarised herein to better understand divergence and biogeography of the extant A. grunniens and extinct Aplodinotus species. Fossil evidence indicates that in addition to A. grunniens, three putative, extinct, marine species in North America and two in South America existed. The North American fossil Aplodinotus range from Oligocene to early Miocene, while the genus extends to the middle Miocene in South America. All described extinct fossil Aplodinotus have been recovered from shallow marine sediments with the oldest from the U.S.A. Gulf Coastal Plain. All sites with extant A. grunniens are from freshwater deposits ranging from middle to late Miocene to Holocene in age which very closely approximate the modern geographic distribution and include a variety of preserved skeletal elements and otoliths. The disappearance of the fossil marine Aplodinotus in the early Miocene in the Gulf is interpreted to represent the genus' transition to brackish and eventually freshwater habitats and development of the extant species by the late Miocene. [ABSTRACT FROM AUTHOR]

The Oligocene fish fauna of the Romanian Eastern Carpathians is of great interest for the study of the extinct European perciform fish assemblages because their diversity and fine preservation. Amongst these deposits, some exceptional fossil localities such as the recently discovered outcrop from the Coza Valley and the well-known historical locations (sites) from Piatra-Neamț and Suslănești, often offer new insights about the Paratethys fish faunas. Herein, we report for the first time the discovery of a fish skeleton originating from the Bituminous Marls Formation exposed in the Coza Valley (Vrancea Half-Window, Marginal Folds Nappe) that we refer to †Dicentrarchus oligocenicus, sp. nov.. Also, we review an existing specimen previously misidentified as †Morone major (Agassiz) found in the Lower Dysodilic Shales Formation of Piatra-Neamț (Bistrița-Râșca Half-Window, Marginal Folds Nappe) that will be referred henceforth to the Percoidei incertae sedis. While the new species described herein has been classified as belonging to the family Moronidae because of obvious meristic, morphometric and osteological features, the other species has been removed from this family due to the lack of diagnostic characters. Remarks on how †Dicentrarchus oligocenicus, sp. nov. differs from all extant and extinct representatives of moronid fishes are given. [ABSTRACT FROM AUTHOR]

Hystricognath rodents arrived in South America from Africa during the Paleogene. The oldest South American rodents (Caviomorpha) were intensively studied in recent years. One of these assemblages is the caviomorph paleofauna from Santa Rosa, Peru. Their age was originally estimated as ?Eocene. Here, we report new caviomorph fossils from Santa Rosa and review the previously described rodents taking into account new dates and updated caviomorph information. We identified 18 genera and 22 species, including one new genus and species (Vucetichimys pretrilophodoncia gen. et sp. nov.), and two new species (Shapajamys minor sp. nov. and Ucayalimys amahuacensis sp. nov.). All taxa are brachydont, with visible cusps, and thin crests. The Santa Rosa rodents are one of the oldest and the most diverse caviomorph paleofaunas known from low latitudes of South America. Similarities between these caviomorphs and other Paleogene assemblages lead us to propose an early Oligocene age for those rodents from the Yurúa River (Brazil) and a close temporal relationship with the oldest known levels from Contamana. This new biochronological scenario has deep implications in the origin and early evolution of caviomorphs. A middle Eocene? entrance of one or several waves of African rodents arriving in South America is possible. [ABSTRACT FROM AUTHOR]

The family Rhinocerotidae, also referred to as 'true rhinoceroses', is one of the multiple perissodactyl lineages that have independently evolved large body sizes, lophodonty (fully developed crests between dental cusps), a simplified anterior dentition, and the molarization of the premolars. During the last decades, descriptions of novel fossil collections, the update of previously published ones, and taxonomic reviews through cladistic analyses have brought to bear a new, comprehensive perspective on the group, significantly increasing its recorded deep-time diversity. This paper reviews the historical development of the study of Rhinocerotidae in the Iberian Peninsula, provides an up-to-date compendium of the regional rhinoceros fossil record by gathering the available references, and presents an updated taxonomic framework. As a result, 27 out of the more than 200 rhinoceros species described in the literature worldwide inhabited the Iberian Peninsula, regionally ranging from the Oligocene to the Late Pleistocene. Their systematics, stratigraphic, and geographical ranges are detailed in the present article and the occurrences and geographical ranges illustrated. [ABSTRACT FROM AUTHOR]

As the largest land mammal that ever lived on the earth, giant rhinos have received much attention from researchers around the world. Here, we use linear models based on limb bone length and circumference measurements of many living animals to estimate the body mass of giant rhinos, with the help of a new composite skeleton of the giant rhino (Dzungariotherium sp.) from the Qingshuiying Formation, Lingwu, northern China. Our estimate suggests that Dzungariotherium sp. from Lingwu is one of the largest giant rhinos known, with a body mass of 20,558 kg. Under the limitation of materials, we estimated the body mass of giant rhinos in as many species as possible by different methods. The body masses of other giant rhinos are also estimated with adjustments based on the new composite skeleton. The data obtained on Dzungariotherium have been considered together with other data on giant rhinos to observe the evolutionary tendency of the group at a large geological scale. It shows that giant rhinos experienced a rapid body size increase since the Late Eocene and divided into three stages, coinciding with the global temperature falling and the spread of the open environment. [ABSTRACT FROM AUTHOR]

This study reconsiders the previous biostratigraphic settings for the Asmari Formation in the eastern Zagros Basin (Fars Basin). The results imply that the Rupelian is identified by the total range zone of the Nummulites species (N. vascus, N. fichteli, N. intermedius). The occurrence of Archaias kirkukensis, A. hensoni, and A. asmaricus before the disappearance of Nummulites species in the current study and even the co-occurrence of the A. hensoni with the mentioned species prevents the use of recently proposed regional stratigraphical framework. The lower part of the Asmari Formation remains without certain age until the occurrence of larger benthic foraminifera throughout the Asmari platform. The coeval biozones for the Chattian Stage are Biozone 59, Biozone 2(b), Archaias asmaricus-A. hensoni-Miogypsinoides complanatus Assemblage Zone, and a part of Assemblage Zone 7 as named by the previous studies. In this study species like Archaias, Austrotrillina, Borelis and Peneroplis are not useful for discriminating the Rupelian and Chattian stages. [ABSTRACT FROM AUTHOR]

(Equisetaceae, Equisetales) is widely distributed around the world and distinguished by obviously jointed stems with longitudinal ridges or furrows. Recently, fossil materials collected from the Shangganchaigou Formation of northwestern Qaidam Basin, China, are assigned to Equisetum based on the presence of jointed stems, longitudinal ridges, and whorls of branch scars. The current specimens are the first discovery of Equisetum in northern Tibetan Plateau and also represent the first fossil record of the genus from Oligocene in Qaidam Basin. The new discovery enriches the knowledge of the paleo-diversity of the Equisetum and indicates that the sphenophytes once existed in the northern Tibetan Plateau. Based on the fossil records in and around the Tibetan Plateau, Equisetum could survive at a higher latitude during the Palaeogene and they could only grow in lower latitude since the Neogene, which might be the result of the tectonic deformation and climatic changes in the northern plateau since the Miocene. The current fossil, together with co-existed fossils, indicate that there have been rich drainages and temperate deciduous broad-leaved forest with grass in northwestern Qaidam Basin during the Oligocene. [ABSTRACT FROM AUTHOR]

Fossils are critical for understanding the environmental changes and uplift history of the Tibetan Plateau during the Cenozoic. As the largest inland basin located at the northeastern plateau, Qaidam Basin has been regarded as the key region to understand the climatic changes in the plateau during the Cenozoic. Herein, fossil legumes from the Oligocene Shangganchaigou Formation in northwestern Qaidam Basin have been reported and are assigned to Desmanthus cf. virgatus (L.) Willd. based on morphological comparison. Current materials represent the first megafossil record of this genus in the world. The living analogues of current fossils now live in regions with mean annual temperature values (MAT) ranging from 13.4 to 29.1°C and mean annual precipitation values (MAP) ranging from 36 to 2874 mm while the MAT and MAP of current northwestern Qaidam Basin is −1.03°C and 60.5 mm, respectively, and indicate that the Oligocene Qaidam was much warmer than today. We calculate that current fossils could grow no higher than 2492 m considering the climatic condition of the Oligocene Qaidam. The difference between estimated and modern elevation of the fossil site suggests that the elevation of the research area has increased by at least ≈1000 m since the Oligocene. [ABSTRACT FROM AUTHOR]

The Oligocene rodent assemblage from Gözükızıllı (Anatolia, Turkey) is described. The assemblage is relatively small, but it contains the new large and hypsodont baluchimyine Daxneria fragilis nov. gen. nov. sp. In addition, the ctenodactyline Sayimys, two new species of Eucricetodon: E. ruber nov. sp. and E. oculatus nov. sp. are present. Rare are the glirids Bransatoglis and Peridyromys/Microdyromys and a dipodid that could not be classified. The assemblage contains Asian and some European elements and is dated as early part of the late Oligocene (29–26 Ma). The small fauna from Gözükızıllı is important because only a few Paleogene rodent faunas are known from Asia Minor. [ABSTRACT FROM AUTHOR]

The flat wasps Bethylidae are a cosmopolitan family of aculeate ectoparasitoid of Coleoptera and Lepidoptera larvae. There are only 73 fossil species so far. Here, we provide a synopsis of the fossil pristocerine, which are those with strongly sexual dimorphism. Comments for all earlier described species are given. Two new genera and two species from Burmese and Taimyr ambers are described and illustrated, †Ekaterina volgatitan Colombo, Gobbi and Azevedo gen. et sp. nov. and †Uniceratops trex Colombo, Gobbi and Azevedo gen. et sp. nov. Four new species from Baltic and Rovno ambers are described and illustrated, †Cleistepyris allosaurus Colombo, Gobbi and Azevedo sp. nov., †Cleistepyris baryonyx Colombo, Gobbi and Azevedo sp. nov., †Pseudisobrachium megalosaurus Colombo, Gobbi and Azevedo sp. nov., †Pseudisobrachium stegosaurus Colombo, Gobbi and Azevedo sp. nov. The species Eleganesia electriphila (Cockerell) is transferred to Foenobethylus and has to be considered Foenobethylus electriphilus (Cockerell) comb. nov. The species Pseudisobrachium oligocenicum Théobald must be excluded from Bethylidae and has to be considered as Hymenoptera incertae sedis. The genus Cleistepyris is recorded for the Old World in the first time. A key for fossil pristocerine is provided. [ABSTRACT FROM AUTHOR]

Fossil insects are very rarely found in sediments of deep marine origin. Nevertheless they can be of great interest to trace past events such as trans-oceanic migrations. Here we document the first fossil insects from Iran, viz. several alate ants dead during mating swarms and a migratory locust, found in the pelagic Oligocene sediments of the Zagros Mountains. This locust represents the first putative indication of insect migrations between the Arabian-African and Asiatic continents through the Parathetys, probably in relation with the development of open grassland biotas in these areas. [ABSTRACT FROM AUTHOR]

The dental pattern ofYindirtemys deflexusfrom Mongolia has been analysed using a Micro-CT scanner. This ctenodactylid exhibits a peculiar dental pattern, characterised by a mesodont dentition with some degree of selenodonty, an intricate enamel folding and elevated connections between cusps. Furthermore, the wear sequence in the upper tooth row shows very worn M1 even before other teeth emerge. The descriptive parameters used in the analyses (Area, Perimeter and structural density) allowed us to determine the relative wear stage in the different dental elements. The study reveals forYindirtemys deflexusa wear pattern typical of mesodont teeth in which the maximum perimeter of the enamel is relatively constant over a large part of the crown height, and the Structural density decreases progressively until the senescence of the tooth. This peculiar dental morphology and eruption sequence ofY. deflexusis interpreted as the result of the evolution towards a relatively more durable dentition caused by the adaptation to more arid environments. [ABSTRACT FROM PUBLISHER]

Caenopithecine adapiform primates are currently represented by two genera from the late Eocene of Egypt (Afradapis and Aframonius) and one from the middle Eocene of Switzerland (Caenopithecus). All are somewhat anthropoid-like in several aspects of their dental and gnathic morphology, and are inferred to have been highly folivorous. Here we describe a new caenopithecine genus and species, Masradapis tahai, from the ~37 million-year-old Locality BQ-2 in Egypt, that is represented by mandibular and maxillary fragments and isolated teeth. Masradapis is approximately the same size as Aframonius but differs in having a more dramatic distal increase in molar size, more complex upper molar shearing crests, and an exceptionally deep mandibular corpus. We also describe additional mandibles and part of the orbit and rostrum of Aframonius which suggest that it was probably diurnal. Phylogenetic analyses place Masradapis either as the sister taxon of Aframonius (parsimony), or as the sister taxon of Afradapis and Caenopithecus (Bayesian methods). Bayesian tip-dating analysis, when combined with Bayesian biogeographic analysis, suggests that a common ancestor of known caenopithecines dispersed to Afro-Arabia from Europe between 49.4 and 47.4 Ma, and that a trans-Tethyan back-dispersal explains Caenopithecus' later presence in Europe. For Masradapis: https://www.zoobank.org/urn:lsid:zoobank.org:act:41BC8459-7CCE-487F-BC59-1C34257D5C4E For Masradapis tahai: https://www.zoobank.org/urn:lsid:zoobank.org:act:C0A620AD-6FCA-4649-A980-FCA237AFE39D [ABSTRACT FROM AUTHOR]

We present new material of the selenodont anthracothereHemimeryx blanfordifrom the Oligocene deposits of the Bugti Hills (Balochistan, Pakistan), collected between 1999 and 2002. This is the first undisputed Oligocene occurrence of the species, previously known from the early Miocene of Pakistan. Investigation of the molar enamel microstructure reveals a surprising mono-zonal Schmelzmuster, already detected in some middle to Late miocene selenedont anthracotheres. We include this observation combined with a morphological revision ofH. blanfordiand a cladistic assessment of the dental evidence, to propose a new phylogenetic hypothesis regardingHemimeryxand its close relatives. We confirm the clade including advanced bothriodontines, which we erect to a tribe rank and name Merycopotamini. The South Asian origin of Merycopotamini is consistent with hypothesized subsequent dispersal events of Merycopotamini from Asia to Africa. [ABSTRACT FROM AUTHOR]

New palm leaves from the Oligocene Ningming Formation are placed into the morphogenusSabalitesbecause of their costapalmate leaf shape. Four taxa are described on the basis of leaf compressions with cuticular structure.S. guanxiensissp. nov. is characterised by hypostomatic leaf blades with a stout costa and a symmetrical base.Sabalitescf.asymmetricushas amphistomatic leaf blades with a long, delicate costa and an asymmetrical base.Sabalitessp. 1 has amphistomatic leaf blades with a long, massive costa and wide segments.Sabalitessp. 2 is characterized by hypostomatic leaf blades with a prominent costa and an asymmetrical base. The four new palm taxa expand our understanding of the floristic elements and features of the Oligocene Ningming flora. Together with the other three palm taxa that were previously reported from the Ningming Formation, our material indicates that the Oligocene Ningming flora had a rich diversity of costapalmate palms. The relatively high species diversity of palms and other plants corroborate that the Oligocene Ningming flora represents a warm and humid climate. [ABSTRACT FROM PUBLISHER]

The muroidCricetopsMatthew and Granger, 1923 commonly occurred in the Oligocene terrestrial deposits in central and northern Asia. Here we report the first record ofCricetopsin the southern part of Asia. Isolated rodent molars named as a new species,Cricetops austersp. nov., were discovered from the early Oligocene sediments at the Lijiawa locality in Yunnan Province in southwestern China. Compared to previously knownCricetops,C. austeris smaller thanCricetops dormitorMatthew and Granger, 1923 andCricetops aeneusShevyreva, 1965, but larger thanCricetops minorWang, 1987. The cusps ofC. austerare less conical. The ridges and crests are longer, higher and thicker. Relatively long and high crests, ridges and arms extending from the main cusps in the new species make those cusps more crescent in appearance than inC. dormitor,C. aeneusandC. minor.C. austeris a rare species in the Lijiawa mammalian fauna. Well-developed shearing tooth crests and ridges ofC. austerprobably suggest a different diet from theCricetopsfrom the northern part of Asia. [ABSTRACT FROM PUBLISHER]

A new fossil species ofZelkovais described from the Oligocene Ningming Formation of Guangxi, South China.Zelkova ningmingensissp. nov.is characterized by leaves with craspedodromous venation pattern and drupaceous fruit type. The new species possesses elliptical to ovate leaves, bearing 7–12 pairs of secondary and simple toothed margin, as well as epidermal cells with straight or rounded anticlinal walls. The species is compared with extant and other fossil species hitherto reported of the genus. It is most similar to the livingZelkova schneiderianain the leaf gross morphology and epidermal characters, which may be suggested to be the ancestral type ofZelkova schneideriana. The discovery ofZelkova ningmingensissp. nov.in Guangxi indicates thatZelkovahas already existed in southern China as early as the Oligocene. In combination withZelkovamaterial from the Oligocene of Europe, it can be inferred that EurasianZelkovahad begun to diversify by at least the Oligocene. Because China is the biodiversity centre of modernZelkova, the fossil herein provides new insights intoZelkovabiogeography. [ABSTRACT FROM AUTHOR]

Cricetid rodents have a very high reproductive capacity and usually a short life span, measured in months rather than years. Many of them are also non-gregarious, searching for new resources outside the confines of their present habitat. These features provide cricetid rodents with valuable attributes as agents of historical biology. We describe a new species of cricetid rodent,Paciculus walshi,an Oligocene cricetid rodent in North America; we characterise its enamel microstructure and dental features and review its relationship with other cricetid rodents globally, to place it within the framework of Oligocene historical biology. [ABSTRACT FROM PUBLISHER]

A series of Oligocene through Early Miocene terrestrial deposits preserved in the foothills of the Zinda Pir Dome of western Pakistan produce multiple, superposed fossil mammal localities. These include small mammal assemblages that shed light on the evolution of rodent lineages, especially Muroidea, in South Asia. Nine small mammal localities span approximately 28–19 Ma, an interval encompassing the Oligocene–Miocene boundary. The Early Miocene rodent fossil assemblages are dominated by muroid rodents, but muroids are uncommon and archaic in earlier Oligocene horizons. The Zinda Pir sequence includes the evolutionary transition to modern Muroidea at about the Oligocene–Miocene boundary. We review the muroid record for the Zinda Pir Dome, which includes the early radiation of primitive bamboo rats (Rhizomyinae) and early members of the modern muroid radiation, which lie near crown Cricetidae and Muridae. The Zinda Pir record dates diversification of modern muroids in the Indian Subcontintent and establishment by 19 Ma of muroid assemblages characteristic of the later Siwaliks. [ABSTRACT FROM PUBLISHER]

Six late Rupelian populations ofNephrolepidina praemarginata(Douvillé, 1908) have been isolated from a succession of the Caltavuturo Formation (Madonie Mts, Sicily). A total of 25 embryonal parameters were obtained from oriented equatorial sections of megalospheric specimens; 8 indexes were derived from selected parameters and 9 indexes were considered for the neanic apparatus, out of which 2 are introduced here:N05(number of annuli in a radius of 0.5 mm) andr5(distance occupied by the first five annuli). The data show marked deviations from the expected trend of traditional biometric measures; this is interpreted as dependent on environmental factors. Previous studies on the succession evidenced an increase in basin depth; this can be inferred also from the biometric analysis of the inner characters of the allochthonousNephrolepidinatests. Here, we explore the paleobiological potential of parameters linked to embryo size and wall thickness, and discuss how depth-dependent parameters may affect the interpretation of evolutionary trends and biostratigraphy in radial foraminifers. [ABSTRACT FROM AUTHOR]

An early Oligocene (Rupelian) diagnostic larger foraminiferal assemblage is described and illustrated from marls and limestones of the Asmari Formation, at Jabals Hafit and Malaqet in the UAE. An equivalent assemblage is identified in the mudstones of the Tahwah Formation, Wadi Suq, Oman. Although Nummulites intermedius (D'Archiac 1846) and N. fichteli are fully synonymous (e.g. Roveda 1970; Schaub 1981; Sirel 2003), in this study both species are biometrically differentiated, distinct and both names are valid. N. fichteli Michelotti 1841, N. intermedius (D'Archiac 1846) and N. emiratus n. sp., which are index for the early Oligocene (Rupelian), and they are replacing each others competitively and environmentally. The presence of Blondeauina bouillei n.gen., N. emiratus n.sp., N. intermedius, N. fichteli, Planoperculina complanata (Defrance 1822) and Austrotrillina asmariensis Adams 1968 ascribed the section of the Asmari Formation to the early Oligocene (Rupelian). The studied marls and limestones were deposited in outer and inner shelf environments, respectively. The Asmari Formation in the area studied consists mainly of marl in its lower portion and reefal limestone in its upper part, indicating a major marine regression. The Tahwah Formation in Oman is composed of bioturbated silty and muddy marls and is a facies equivalent to the Asmari Formation marls. The Asmari Formation facies change probably relates to a mid-Oligocene fall in global sea level. In this study, the Dabaa Formation, a subsurface unit of late Eocene-Oligocene marine shales in the north Western Desert of Egypt, was chosen to correlate with the Oligocene of Emirates and Oman. The Dabaa Formation comprises Spiroclypeus ornatus (Henson 1937) and Eulepidina dilatata (Michelotti 1861). The environment of deposition was inner shelf to littoral, which become estuarine towards the top in many areas. This Oligocene Dabaa sequence is correlatable with Wadi El Arish sequence recently discovered by Kuss and Boukhary (2008) from Risan Aneiza, Northern Sinai, Egypt. [ABSTRACT FROM AUTHOR]