Eocene - Science topic

Rhinoceros, whose strains are almost extinct today, are one of the most prevalent successful mammal groups living from 40 million years to now. While rhinos that appeared in different places of the world in different era were seen for the first time in the Northern Hemisphere during the Middle Eocene period, they appeared in the Early Miocene perio...

Amynodontidae Scott & Osborn, 1883 are an extinct family of Rhinocerotoidea Owen, 1845 known from the middle Eocene to the latest Oligocene of Asia, North America, and Europe. We report here two unpublished specimens of Amynodontidae, a skull and a mandible of Zaisanamynodon borisovi Belyaeva, 1971 from the late Eocene of the Zaysan Basin (Kazakhst...

The Li-enriched oilfield brine is a very important lithium resource. It has gained much attention and become the target of active Li surveys with the growing global demand for Li. However, only little is known about their feature and nature. In the study, hydrochemical data from 155 oil wells tapping the Eocene to Lower Oligocene Qianjiang Formatio...

The Cenozoic succession of the Jabal Hafeet anticline yields the most complete surface expression of the deformation that affected the Southeast Arabian Foreland Basin (SEAFB). The carbonate rocks of the Eocene Rus Formation comprise the core of the Jabal Hafeet anticline and host a network of fractures and carbonate veins associated with dynamic f...

Unlabelled: Trionychid (softshell) turtles have a peculiar bauplan, which includes shell reductions and cranial elongation. Despite a rich fossil record dating back to the Early Cretaceous, the evolutionary origin of the trionychid bauplan is poorly understood, as even old fossils show great anatomical similarities to extant species. Documenting s...

House flies (Muscidae) comprise the most species-rich family of the muscoid grade with over 5000 described species worldwide, and they are abundant in various terrestrial and aquatic ecosystems. The high number of species, varied appearances, complex feeding habits, and wide distributions have hindered researchers from understanding their phylogeny...

The latest Eocene Lagerstätte Florissant Formation (FF, 34.1 Ma) at Clare’s Quarry, Teller County, Colorado, contains a diverse flora and fauna preserved in lacustrine facies. In the late Eocene, during the deposition of the FF, the climate was warm temperate to subtropical and deciduous broadleaved plants and exotic tall conifers were present. Thi...

The interplay between structural and metamorphic processes operating along the deep plate interface in subduction zones remains elusive as much of the geologic record is recycled into the mantle. In some cases, metamorphosed subducted rocks are underplated and exhumed to the surface, providing critical constraints on structural processes and the rh...

The most intense arc magmatism in the Gangdese arc occurred during the Palaeocene–Eocene, which is widespread across the entire southern Lhasa subterrane with Palaeocene–Eocene I‐type intrusive rocks and Linzizong volcanic successions. What drives the voluminous magmatism remains enigmatic. New geochronological and geochemical data on Late Cretaceo...

Spikelets, inflorescence fragments, whole plants and isolated leaves have suites of characters that suggest affinities with Poaceae. Spikelets are borne alternately on delicate axes with slightly unequal glumes subtending two florets each with three stamens. Anthers are dorsifixed. Pollen characters are important in delimiting Poaceae from other ta...

Deformational history of the Hazara basin indicates a primitive collision of the two landmasses that undergoes an episodic deformation with NE-SW structural trend. Panjal Thrust (PT) and Main Boundary Thrust (MBT) demarcate the northern and southern extremities of the basin, respectively. The area bounded between these two thrusts is the core consi...

The Neotethyan subduction and collision with the Asian, Indian, and Australian plates is evidenced by a giant Andean-type arc system and a remarkable Neotethyan igneous belt along the southwestern Eurasian margin. However, the southward extent, and cause, of Neotethyan subduction is poorly understood. Here, a zircon U-Pb dating and whole-rock geoch...

The emergence and expansion of terrestrial C4 vegetation represent the most striking evolutionary adaptation of ecosystems to climate change during the Cenozoic. However, the long-term history of terrestrial C4 ecosystem expansion in East Asia remains poorly documented, and its links to tectonic and/or climate changes remain unclear due to the comp...

The first fossil Typhlocybinae inclusions from Eocene Rovno amber are described and illustrated. They include two new monotypic genera of the extinct tribe Protodikraneurini, Retrorsotettix n. gen. with type species R. vlaskini n. sp. and Protoparallaxis n. gen. with type species P. clavatus n. sp. Also described and illustrated are two new monotyp...

In the external zones of mountains belts, it is now recognize that tectonic inheritance and early salt activity (halokinesis) prefigure and localize posterior tectonic structures. Taking this heritage into account leads to reevaluate some mechanisms, classically invoked to explain the emplacement of fold-thrust structures. The Corbières region, in...

The early Cenozoic marine sedimentary record is punctuated by several brief episodes (<200 kyr) of abrupt global warming, called hyperthermals, that have disturbed ocean life and water physicochemistry. Moreover, recent studies of fluvial–deltaic systems, for instance at the Palaeocene–Eocene Thermal Maximum, revealed that these hyperthermals also...

The temperature changes in the middle-late Eocene had a profound impact on various ecosystems around the world. This has been confirmed not only in marine sediments but also in lake ecosystems, which have provided more detailed isochronous continental sedimentary records. Based on systematic palynological and element analyses of fine-grained lacust...

The Pearl River Mouth Basin (PRMB) is located in the northern part of the South China Sea. The Palaeogene Wenchang Formation (Fm) was formed at the rift stage and contains the main source rocks. The migration of Wenchang subsidence centres in the western Zhu I Depression and northern Yangjiang-Yitong Fault Zone are controlled by tectonic transforma...

The middle Eocene was a key phase in East Asian and global climate evolution; however, the understanding of the astronomical driving mechanisms of key climate changes during this phase in eastern China is lacking. A 390-m-thick, continuous lacustrine mudstone succession in the Dongying Depression (eastern China) provides an ideal middle Eocene sedi...

A new genus and species of the braconid parasitoid subfamily Doryctinae, Palaeorhoptrocentrus kanti Belokobylskij, gen. et sp. nov., from the late Eocene Baltic amber are described and illustrated from two females. This genus is characterised by the fore wing having postfurcal position of the recurrent vein (m-cu), distally closed brachial (second...

Given the high degrees of adaptation to specific microhabitats and restricted-range endemism, Goniurosaurus (Tiger geckos) serves as a unique model to study the complex evolution in lizards. Using phylogenetic analyses, we estimated the first divergence date of Goniurosaurus to the Eocene (~ 45.3 mya). The diversification within four monophyletic s...

Fossil weevils of the subfamily Molytinae are currently represented by 103 species in 42 genera from 14 tribes. Fossil records of the tribe Aedemonini are known from the Eocene of Europe. This tribe makes up 22% of the London Clay weevil specimens identified to the genus level and 16% of the Curculionidae genera. At present, the distribution of thi...

To assess zonal temperature and biogeographical patterns in the Southern Ocean during the Paleogene, we present new multi‐proxy air‐ and sea‐surface temperature data for the latest Paleocene (∼57–56 Ma) and the Paleocene‐Eocene Thermal Maximum (PETM; ∼56 Ma) from the northern margin of the Australo‐Antarctic Gulf (AAG). The various proxy data sets...

This study focuses on identifying the relative age in rock sequence of the Ratga Formation (Swab Member), Iraqi Western Desert. To achieve this goal, five samples are collected (mainly limestone) from the Keyhole KH7/7, at a depth between (119-130). Nineteen species belonging to eleven genera of calcareous nannofossils are described. The recorded a...

In Meghalaya, coal is present in the Lakadong sandstone formation (25 to 250 meters thick) of the Eocene epoch. The three major clusters of coalfields in Meghalaya are the Garo Hills, Khasi Hills, and Jaintia Hills. Based on petrographic studies, tectonics, and sulphur content, done by many scientists, it has been suggested that the coal-bearing st...

The rapid expansion of economic activities in Egypt’s Central Eastern Desert has resulted in poorly coordinated groundwater development, having a negative impact on the resource. This study was conducted to assess the hydrochemical characteristics of the different aquifers in the Central Eastern Desert, with an emphasis on the impact of seawater in...

This article aims to provide a simple and applicable method of measuring the rock accumulation rate and recording the depositional events based on the application of graphic correlation and similarity matrix of the Paleogene planktonic foraminifera in two surface sections in South Sinai. Fifteen continuous biozones and subzones were recorded spanni...

Several foraminiferal assemblages were recorded around the Orduzu-Pınarbaşı, Battalgazi district of the Malatya province. The studied foraminiferal assemblages yield the middle Eocene (Lutetian-Bartonian) age for the Suludere and Gedik formations in the study area. Benthic foraminiferal genera are Anomalinoides, The carbon isotope provides informat...

Artiodactyls diversified during the Eocene and Oligocene in North America and Europe after their first Holarctic appearance at the beginning of the Eocene. However, the relationships among early artiodactyls, European endemic forms, and later derived suiforms, tylopods, and ruminants remain unclear. Early artiodactyls are relatively rare in Asia co...

The shale of the upper Es4 formation (Es4 u), deposited during the Eocene in the Boxing Subsag of the Dongying Sag, is a typical set of lime-rich lacustrine shale in a continental rift basin. Through logging data interpretation, core and thin section observations, and geochemical elements [obtained by X radial fluorescence (XRF) mud logging] analys...

Insight into the evolution of Philippine Sea‐South China Sea (SCS) plate motions helps reveal the driving mechanisms of the long‐term tectonic complexity in Southeast Asia. Here, based on the integration of the most recent geological and seismic data, we present a new plate reconstruction model for this region characterized by back‐arc extension an...

The Plateau des Dômes overhangs the Limagne graben by several hundred metres and represents the basement of a Quaternary volcanic chain oriented north-south, the Chaîne des Puys (CdP), consisting of about 80 volcanic edifices spread linearly over thirty kilometers. Since its final emersion in the late Cretaceous, the Plateau des Dôme has been mainl...

Records of Paleogene arctoids are scarce in Asia, but there are abundant records in Europe and North America. In this study, we report a new arctoid taxon, Lonchocyon qiui gen. et sp. nov., from the late Eocene Baron Sog Formation of the Erlian Basin, Inner Mongolia, China. This is the first report of a relatively complete, large arctoid taxon from...

Volcanic arc degassing contributes significantly to atmospheric CO2 levels and therefore has a pivotal impact on paleoclimate changes. The Neo-Tethyan decarbonation subduction is thought to have played a major role in Cenozoic climate changes, although there are still no quantifiable restrictions. Here we build past subduction scenarios using an im...

At present, a strong latitudinal sea surface temperature (SST) gradient of ~16 °C exists across the Southern Ocean, maintained by the Antarctic Circumpolar Current (ACC) and a set of complex frontal systems. Together with the Antarctic ice masses, this system has formed one of the most important global climate regulators. The timing of the onset of...

The evolutionary history of latex, a widespread chemical defense against insect herbivores, is not fully understood, yet a more detailed understanding of the fossil record of latex could help answer important evolutionary questions. This is, however, hampered by the difficulty of recognizing fossil latex and our still incomplete comprehension of th...

Estimates of global mean near‐surface air temperature (global SAT) for the Cenozoic era rely largely on paleo‐proxy data of deep‐sea temperature (DST), with the assumption that changes in global SAT covary with changes in the global mean deep‐sea temperature (global DST) and global mean sea‐surface temperature (global SST). We tested the validity o...

Elevation-dependent temperature change is a phenomenon found in mountain regions with complex terrain, mostly in the Himalayas and the high terrain of the Tibetan Plateau, where regions in high elevation feature high rates of warming than the region in lower elevation. This pattern referred to as elevation-dependent warming. However, does elevation...

The evergreen versus deciduous leaf habit is an important functional trait for adaptation of forest trees and has been hypothesized to be related to the evolutionary processes of the component species under paleoclimatic change, and potentially reflected in the dynamic history of evergreen broadleaved forests (EBLFs) in East Asia. However, knowledg...

A new hyaenodont Maocyon peregrinus , gen. et sp. nov., is described based on a partial skull and associated mandible from the upper Eocene Youganwo Formation at Maoming locality in Guangdong Province, China. It shows certain similarities with the Hyainailouroidea in the skull structure, including anteroposteriorly extended jugal/squamosal suture,...

The Eastern Venezuelan basin is located south ofthe Serrania del Interior Oriental range, which represents the easternmost branch of the Andean uplift (Figure I). The northernmost boundary of the Serrania del Interior Oriental range, is controlled by right lateral strike-slip motion. It includes the El Pilar Fault system, a major dextral fault, con...

The old Valfonda quarry is located at the northern end of the Maestrazgo Geopark in Alcorisa (Teruel). The quarry benefited stratified sandstones in banks up to several meters thick deposited in fluvial or alluvial fan systems during the late Eocene to early Oligocene. These sandstones are part of the detrital fill of the Alloza basin developed dur...

The lacustrine fine-grained sedimentary rocks in the upper interval of the fourth member of the Eocene Shahejie Formation (Es4s) in the Dongying Depression are important shale oil exploration targets in Bohai Bay Basin. They are widely distributed and rich in organic matter. In this study, samples were observed under the optical microscope and FESE...

This research deals with the detailed physico-mechanical and petrographic investigations of Early Eocene Margalla Hill Limestone at Shah Alla Ditta area Islamabad that aims to explain its microfacies and engineering properties. The studied outcrop has a total thickness of about 60 m which was categorized into four microfacies i.e., bioclastic mudst...

Xenophagus simutniki sp. n. is described from a late Eocene Rovno amber specimen. The new species is similar to the fossil Xenophagus popovi Lyubarsky et Perkovsky, 2017 from the late Eocene Baltic amber (W Russia), differing in the medially notched anterior margin of the pronotum. The Rovno xenosceline fauna is the richest among both extant and ex...

The late Eocene succession of the Dongying Depression forms a highly productive hydrocarbon source. However, due to lack of an unambiguous fine chronostratigraphic framework for the late Eocene stratigraphy, it is challenging to understand the paleolake’s evolution and the driven mechanism of lake-level variation, a limitation which hinders hydroca...

During ontogenetic development, insects can undergo quite drastic changes (metamorphosis) until the adult stage is reached. A substantial part of this development in one group of Insecta, Holometabola, takes place during the pupa stage. Despite the pupa being recognised as an important phase, rather few depictions of pupae exist in the literature....

Ongoing rapid climate change has a major effect on marine fauna, and understanding these faunal changes analogous to future climatic periods is crucial. The Oligocene is commonly considered a critical transition period, linking the archaic world of the tropical Eocene and the more modern ecosystems of the Miocene. Here, we show the response of mari...

The subfamily Plectorhinchinae (sweetlips) is composed of poorly-known species with high commercially and ecologically values that exhibit phenotypic plasticity and various morphologies. Few studies have assessed the validity of sweetlips, intergeneric relationships and evolutionary survey in this subfamily, which have not yet been resolved. This s...

Previous studies have shown that shale oil mobility depends on the relative content of free oil and adsorbed oil. However, the research on how to establish a shale oil mobility evaluation is relatively insufficient. This study aims to use pyrolysis data before and after extraction to accurately identify the content of free oil and adsorbed oil, ana...

Turtle shells frequently exhibit anomalous osseous modifications on their surface which can sometimes compromise the survival of the organism. Nowadays, despite the large number of anomalies identified in both extant and extinct turtle shells, the etiology, as well as the pathogenesis, of the various osseous modifications remains unknown in most do...

Carbonate rocks are common in many parts of the world, including the Eastern Mediterranean, where they host significant groundwater supplies and are widely used as building and ornamental stones. The porosity of carbonate rocks plays a critical role in fluid storage and retrieval. The pore structure connectivity, in particular, controls many proper...

Background and Aims Cork oaks (Quercus sect. Cerris) comprise 15 extant species in Eurasia. Despite being a small clade, they display a range of leaf morphologies comparable to the largest sections (>100 spp.) in Quercus. Their fossil record extends back to the Eocene. Here, we explore how cork oaks achieved their modern ranges and how legacy effec...

Ferns are important components of the biodiversity of wet forests across Canada, and the fossil record offers insights into the origins of fern diversity and biogeography. In 1967, Driftwood Canyon Provincial Park in north-central British Columbia was declared an Eocene Epoch plant, insect, fish, bird, and mammal fossil site of national scientific...

For a hundred years the Saint Jacques area has been known to produce rich Oligocene vertebrate fossils, yet only a handful of previous studies have focused on this area. Since 2010, we have conducted 12 field expeditions to Saint Jacques, and here we report findings from our paleontological excavations and stratigraphical investigations. Twenty-two...

Abstract: Subject of this study are fossils of Eocene marine molluscs found in Amiret El Fehoul, Monastir, Tunisia. The collected material from many years, then will donate them to the Natural History Museum. Fossils were kindly provided to the Geological Museum of the National Office of Mines for identification, cataloging and describing and lat...

Folegandros island lies between the established SW‐directed West Cycladic and S‐directed Santorini detachment systems. Preserving shear sense indicators with opposing kinematics, the geodynamics and timing of kinematics are debated. Using white mica 40Ar/39Ar geochronology complemented by structural data we report a new Miocene top‐to‐S detachment...

Sustainable groundwater resources are a critical issue for national development in developing countries like Egypt, which is characterized by a semi-arid to arid climate and low per capita share of fresh water as a result of progressive population increase and especially after the construction of the Great Ethiopian Renaissance Dam. It is mandatory...

Matija Vertovec, fossil collector and promoter of palaeontology. (In memory of fossil collector and bibliophile Stanislav Bačar from Ajdovščina) ENG. // Matija Vertovec, zbiralec okamnin in razširjevalec paleontoloških spoznanj med ljudmi (V spomin na ajdovskega zbiralca fosilov in bibliofila Stanislava Bačarja) SLO. // Matija Vertovec (1784-18...

A new genus and species of the braconid parasitoid subfamily Doryctinae, Eocenhecabolus kotenkoi gen. et sp. nov. , from the late Eocene Rovno amber are described and illustrated. Eocenhecabolus gen. nov. is the first unambiguously extinct Doryctinae genus. This genus is described from the male and characterised by the followings features: in the f...

Despite the economic importance of the Waihapa Field in Taranaki Basin in New Zealand, the structural setting, petrographic and petrophysical properties of its Cenozoic reservoirs are still poorly understood. This research integrates a 3D seismic survey with core and well logs data, as well as petrographic description in order to discuss the struct...

The Poster shoes changing of the Penjween area from ophiolite and igneous rocks to sedimentary succession of mainly metamorphosed greywackes and fossiliferous limestones of Paleocene and Eocene