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The Rashrashiyah Formation of the Sirhan Basin in northern Saudi Arabia contains diverse assemblages of planktonic foraminifera. We examined the biostratigraphy, stratigraphic range and preservation of upper Eocene planktonic foraminifera. Assemblages are well-preserved and diverse, with 40 species and 11 genera. All samples are assigned to the Priabonian Globigerinatheka semiinvoluta Highest Occurrence Zone (E14), consistent with calcareous nannofossil biostratigraphy indicating Zone CNE17. Well-preserved planktonic foraminifera assemblages from the lower part of the upper Eocene are rare worldwide. Our study provides new insights into the stratigraphic ranges of many species. We find older (Zone E14) stratigraphic occurrences of several species of Globoturborotalita previously thought to have evolved in the latest Eocene (Zone E15, E16) or Oligocene; these include G. barbula, G. cancellata, G. gnaucki, G. pseudopraebulloides, and G. paracancellata. Older stratigraphic occurrences for Dentoglobigerina taci and Subbotina projecta are also found, and Globigerinatheka kugleri occurs at a younger stratigraphic level than previously proposed. Our revisions to stratigraphic ranges indicate that the late Eocene had a higher tropical–subtropical diversity of planktonic foraminifera than hitherto reported. [ABSTRACT FROM AUTHOR]

The Eocene record of substantial aridification near Tibet was reported to mimic the global climate cooling trend, overwriting the previously proposed dominant role of the Tibetan Plateau uplift in the aridification (Li et al., 2018, https://doi.org/10.1038/s41467‐018‐05415‐x). Here we present new paleoclimate data from the red clay sequence deposited between 40 and 50 Ma in Altun Shan at the northeastern edge of the Tibetan Plateau. After building an age model using a compilation of magnetostratigraphy and cyclostratigraphy, we demonstrate that our record of magnetic susceptibility in the Altun Shan red clay exhibits variations linked to eccentricity cycles. Our age model allows us to estimate the age of eight short geomagnetic events, cryprochrons, in Altun Shan. Further we show that the aridification interval in Altun Shan coincides with (i) a cooling event recorded in the global oxygen isotope record, (ii) a sea surface temperature record on the east Tasmanian plateau, and (iii) an aridity record in the surrounding sedimentary basins of Central Asia. The middle Eocene aridity and cooling reached its maximum 45.5‐44 Ma. Plain Language Summary: Two notable Eocene climate warming events are extensively discussed in the literatureߝthe middle Eocene climatic optimum and the early Eocene climatic optimum. Here, we report our accurately dated climate proxy record of magnetic parameters from the Altun Shan red clay section at the northeastern part of the Tibetan Plateau that reveals an aridity interval 45.5‐44 Ma. The Altun Shan magnetic susceptibility record, an indicator of aridity vs. moisture intensification intervals, exhibits variations linked to eccentricity cycles. The one and a half million yearlong aridity event in Altun Shan coincides with the aridity in middle Asia and the cooling event that could be observed in the global oxygen isotope compilation and the first appearance of ice‐rafted debris from Greenland and Pan‐Arctic sources, indicating global distribution of aridity and cooling 45.5‐44 Ma. Key Points: A magnetic record of the Eocene section near Tibet reveals a one and a half million yearlong aridityThe aridity interval 45.5‐44 Ma coincides with aridity maximum in inner AsiaThe middle Eocene aridity coincides with cooling registered in oceanic records [ABSTRACT FROM AUTHOR]

Here, we describe the first skeletal remains of Notostylops recovered from middle Eocene levels of the Sarmiento Formation, Patagonia, Argentina. The remains include two teeth of Notostylops murinus, the axis, vertebral bodies, a rib, a left humerus, both radii, two metapodials, two phalanges, the pelvis, a right femur, a right calcaneus and several broken bones. Radial bones are not fused to ulnas, and are shorter than the humerus, very generalized, with an oval head, a marked neck and a radial tubercle. The humerus and the femur show pronounced insertion structures. Our analysis suggests that the appendicular skeleton of Notostylops is too generalized and shares several features with that of terrestrial rodents as Sciuridae. Unlike the appendicular skeletons of cursorial or saltatorial mammals, which restrict mobility, the skeleton of Notostylops indicates the ability to make a variety of different movements, as would be expected for terrestrial, fossorial or arboreal mammals. This skeleton gives new information about the locomotor behaviour of notoungulates, particularly in their basal forms. The results will also allow the identification of isolated notoungulate bones and raise questions about the previous taxonomic assignment of postcrania to Pleurostylodon. [ABSTRACT FROM AUTHOR]

Foraminiferal evidence from two sites in southern Maryland, eastern United States, reveals a series of rapid environmental changes on the continental shelf during the onset of the Paleocene‐Eocene Thermal Maximum (PETM). Benthic and planktic foraminifer assemblages from the South Dover Bridge and Mattawoman Creek‐Billingsley Road coreholes in the central Salisbury Embayment record changing latest Paleocene and earliest Eocene environmental conditions that began prior to the carbon isotope excursion that marks the beginning of the PETM. The foraminiferal response reflects increases in productivity in the bottom water, a minor dissolution event, and sea surface warming in the latest Paleocene. Relative sea level changes, a sudden change in sedimentary regime, and a decrease in bottom water oxygenation occurred in this region across the PETM onset. While South Dover Bridge assemblages support a rise in sea level across the PETM onset, Mattawoman Creek‐Billingsley Road assemblages record a reduction in water depth interpreted as delta progradation and possible tectonic activity. Transitional carbon isotope values are recorded in these delta sediments. We present an initial bathymetric reconstruction of the Salisbury Embayment showing the physical effects of the carbon isotope excursion onset on shelf morphology and highlight the importance of understanding coastal zone processes when examining shelf sediments. Key Points: Foraminiferal evidence documents a series of ecological changes in the Salisbury Embayment at the Paleocene‐Eocene Thermal Maximum onsetReconstructed shelf geomorphology describes a late Paleocene depo center that rapidly accumulates delta sediments in the early EoceneThis research highlights the importance of considering coastal zone processes when making paleoceanographic interpretations on the shelf [ABSTRACT FROM AUTHOR]

Highlights • High resolution tomographic image of the crust and uppermost mantle beneath NWDVP. • Tectonic and monsoon induced earthquakes of M ≥ 5, associated with low-V and high-Vp/Vs. • Variations in the depth to the Moho signify alterations due to tectonic processes. Abstract The northwestern Deccan Volcanic Province (NWDVP) in India has undergone major tectonic changes during the Eocene–Paleocene, when voluminous eruptions took place due to interaction of the Indian plate with the Reunion plume. The intense seismic activity makes this region as the most vulnerable intraplate earthquake zones, world over. In this study, we utilize arrival times of 40,499 P and 39,581 S phases from waveforms of 5653 events registered at 93 seismic stations to obtain high-resolution tomographic images of the crust and uppermost mantle beneath the NWDVP. The images shed light on the relation between seismicity and seismic structure in the source regions of two large earthquakes (Mw ≥ 7.7) at depths >20 km in the rift basins, shallower moderate (Mw ∼5) quakes and swarm induced activity in the horst region. Higher Vp/Vs ratios are observed for the seismogenic rock matrix with entrapped magma fluid that played an important role in triggering large and moderate tectonic earthquakes. High Vp/Vs ratios are also observed in the uppermost crust, indicating that fluid in sediments/fractures triggers the swarm and induced seismicity. The source zones of the shallow, mining induced seismicity are imaged as low Vp, Vs zones. The vertical and horizontal intrusions of the Deccan volcanic magma in the uppermost mantle and lower crust are also well imaged as high Vp and Vs anomalies. Variations in the depth to the Moho and lower crustal velocities signify alterations due to tectonic processes during different time scales. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Radiolarian and U–Pb ages examined in the Mugi and Naharigawa units, Southwest Japan. • The Late Cretaceous to Paleocene Mugi Unit contains abundant syn-depositional zircons. • The Eocene Naharigawa Unit lacks syn-depositional detrital zircon. • Temporal variations in provenance record igneous activity and basement uplift. • The Aki Tectonic Line developed within the Cretaceous accretionary complex. Abstract In this study, we describe radiolarian fossils, analyze sandstone petrography and geochemistry, and perform detrital zircon U–Pb dating on the Late Cretaceous and Paleogene Shimanto accretionary complexes. These data are used to constrain temporal variations in provenance, which are related to volcanic arc activity. We also determine the behavior of the Aki Tectonic Line, which represents an out-of-sequence thrust. Based on lithology and radiolarian assemblages, we subdivide the Late Cretaceous to early Paleocene Mugi Unit into the Mg1, Mg2, and Mg 3 subunits, and the Eocene Naharigawa Unit into the Nh1 and Nh2 subunits. Detrital zircon U–Pb ages indicate that sandstones of the Mugi Unit were sourced mainly from Late Cretaceous to Paleocene igneous rocks. Nh1 sandstone records a single peak age in the Late Cretaceous, whereas Nh2 sandstone preserves multiple peaks from the pre-Jurassic to early Paleocene. The Naharigawa Unit lacks syn-depositional detrital zircons; however, felsic tuff within Nh1 records an age of 48.7 Ma, which is consistent with radiolarian ages. The Nh1 and Nh2 sandstones contain slightly higher Ba and Rb concentrations than those of the Mugi Unit, suggesting that basement had been uplifted and eroded in the source region, prior to deposition. We conclude that temporal variations in sandstone composition within the Late Cretaceous to early Paleocene Shimanto accretionary complex resulted from tectonic events that occurred in response to syn-depositional igneous activity. We infer that the evolution of the Eocene Shimanto accretionary complex was influenced by uplift and erosion of pre-Jurassic basement. Late Cretaceous radiolarians were identified in subunit Mg3 that forms the footwall of the Aki Tectonic Line, which was previously interpreted as a boundary fault between the Late Cretaceous and Paleogene Shimanto accretionary complexes. The Aki Tectonic Line is re-interpreted as an out-of-sequence thrust (OST) that was active under low-grade metamorphic conditions. We classify several OSTs close to the Late Cretaceous and Paleogene Shimanto accretionary complexes, based on contrasts in metamorphic grades across the faults. Within the study area, the Aki Tectonic Line is classified as a Type-2 OST, indicating that it developed within the Cretaceous Shimanto accretionary complex at temperatures of 250–270 °C. [ABSTRACT FROM AUTHOR]

Abstract Petrographic examination, heavy mineral analysis and detrital zircon U-Pb dating were performed on the Eocene siliciclastic rocks in the Rača Unit of the Outer Western Carpathians in order to reveal their origin and establish the development of the Magura Basin during the Eocene. The medium- to fine-grained sublitharenites and quartzarenites were mainly derived from extra-basinal sources, and the deposits predominantly contain minerals from metamorphic rocks. The terrigenous material was derived from low- to medium-grade metapelites and granitoids. The sedimentation was also controlled by a sediment supply from the mafic source. The basic and metabasic rocks contain pyrope-rich garnets and Cr-spinels. Palaeo-currents document that the sedimentary material was supplied from the South-East. The first detrital zircon U-Pb ages confirm zircon-producing events occurring in the Proterozoic from approximately 2200 to 590 Ma; but predominantly in the Paleozoic between 550 and 60 Ma. The palaeocurrent indicators, petrographic data, heavy mineral spectra and zircon geochronology strongly suggest that the Tisza Mega-Unit Variscan crystalline basement erosion with accompanying sedimentary cover supplied the Magura Basin from the South. The Mecsek Zone is also suggested to support the Villáni-Bihor and part of the Békes-Codru zones in supplying the Magura Basin during the Eocene to Oligocene. The Eocene transport of significant detrital material to the Magura Basin is also related to erosion of the Marmarosh Massif Proterozoic–Ordovician low- to medium-grade crystalline basement. Therefore, it is most likely that Magura Basin sedimentation was dominated by supply from the sub-ophiolitic Fore-Marmarosh Suture Zone of the Eastern Carpathians. Highlights • First report of the U-Pb zircon dating of the Magura Nappe siliciclastic rocks • Corrosion and geochemistry of the heavy minerals to determine their provenance • Palaeogeography of the Magura Basin during the Bartonian–Early Priabonian [ABSTRACT FROM AUTHOR]

Abstract Potassic high Ba-Sr granitoids are widely distributed over collisional orogenic belts worldwide, however, their magma sources and petrogenetic processes are still debated. To better understand them, we collected a suite of Paleogene high Ba-Sr granitoids in the Jianchuan Basin, southeast Tibet. Based on the mineralogical compositions, major and trace element geochemistry, and age of formation, we subdivide them into two groups: intermediate series and granitic series. LA-MC-ICP-MS zircon U-Pb analyses show that the intermediate series crystallized at 33.8–36.9 Ma, similar to or slightly earlier than the granitic rocks with crystallization ages of 33.1–34.0 Ma. New geochemical and zircon Hf isotopic results, in combination with previous results, support an enriched mantle source for the high Ba-Sr intermediate rocks, and a mixed source of enriched mantle and lower crust for the granitic ones. We suggest that partial melting of enriched mantle with fractional crystallization of mafic minerals produced the potassic high Ba-Sr intermediate series. Meanwhile, the juvenile heat from such magma induced melting of thickened lower crustal materials which together with magma from mantle accounted for source of the granite series. The high Ba-Sr intermediate rocks have nearly identical major and trace element, and isotopic signatures as Archean sanukitoids, thus offer a potential constraint on the formation mechanism for the sanukitoids. Our study supports that the emergence of the sanukitoids requires a sediment-metasomatized mantle and thus indicates the onset of crustal recycling into the mantle. Highlights • A suite of high Ba-Sr rocks emplaced in Jianchuan Basin in the late Eocene. • High Ba-Sr intermediate series represent magma derived from an enriched mantle. • High Ba-Sr granites were mixed products of from mantle as well as from lower crust. • Sanukitoids indicate the onset of crustal recycling into the mantle. [ABSTRACT FROM AUTHOR]

Abstract The early Eocene is characterized by a warmer phase, even at high latitudes. The CO 2 level ranged from 1000 to 2000 ppm due to the increase in volcanic activity. The climate dynamics of the Indian subcontinent and biotic exchange between the neighboring continents can be traced by studying the Eocene fossil assemblages which are nicely preserved in the rock records. Fossil records from early Eocene sites are important for their potential contribution in our understanding of interactions between climate and biota. In western part of the Indian subcontinent, extensive lignite deposits are known in the states of Gujarat (Kutch and Cambay basins) and Rajasthan (Barmer and Bikaner-Nagaur basins). These lignite deposits have been investigated for their faunal and floral content. Based on the nearest living relatives (NLRs), it has been concluded that a highly diversified tropical evergreen forest was present in most of the basins of western India and this fact has been supported by the equatorial position of the Indian subcontinent during the early Eocene. Fossil records of Rhamnaceae, Combretaceae and Lythraceae known since the Late Cretaceous in India indicate their possible Gondwanan origin. Highlights • Early Eocene assemblage from western India is based on leaves, woods and fruits. • Tropical evergreen forest can be reconstructed for Cambay basin during early Eocene. • Evidences from the early Eocene lignite mines indicate a strong seasonal rainfall. • Gondwanan origin has been suggested for Rhamnaceae, Combretaceae and Lythraceae. [ABSTRACT FROM AUTHOR]

We describe a new lizard taxon, Stefanikia siderea gen. et sp. nov., from the early-middle Eocene locality of Messel in Germany based on a nearly complete skeleton, which we studied using μCT methods. It shares many characters with the Eocene taxon Eolacerta, which is broadly distributed in the Eocene of central and Western Europe, but is much smaller and shows several important anatomical differences. The new discovery sheds light on the paleodiversity of these lizards in the Eocene of Europe, and the new family name Eolacertidae is proposed to encompass Eolacerta and Stefanikia. The relationships of Eolacerta have been intractable. Our phylogenetic analyses confirm that Eolacertidae is a member of the clade Lacertiformes and provide strong support for a sister-group relationship to Lacertidae. In some places, skin impressions are preserved, displaying the body scalation. As such, the exquisitely preserved specimens of Eolacertidae from Messel provide new insight into the morphology and ecology of lizards on the stem of Lacertidae, Europe’s dominant group of living reptiles. http://zoobank.org/urn:lsid:zoobank.org:pub:DFD01563-A913-4286-B64B-E0912474FD08 [ABSTRACT FROM AUTHOR]

A detailed anatomical analysis is here presented focused on a notoungulate skull recovered from sediments of the lower part of the Quebrada de los Colorados Formation (LC I; late middle Eocene), cropping out in Salta Province, Argentina. The material was identified as a Toxodontia, although it does not exhibit information useful enough for its generic or even familiar assignment. The description was mainly focused on the basicranium and the auditory region (especially the petrosal and auditory ossicles) given the better preservation of these parts in the specimen. Additionally, a phylogenetic analysis was conducted based on previous studies dealing with a wide sample of South American Native Ungulates. This specimen exhibits some traits traditionally mentioned for the suborder Toxodontia, such as the horizontal bullar septum, and others recently regarded as synapomorphies of Notoungulata, including the lateral location of the tensor tympani fossa and the expanded medial margin of the petrosal. However, it also shows some unexpected features for that suborder of notoungulates, such as the presence of a strongly curved promontorium. The study of this skull increases our knowledge of the auditory anatomy of Eocene Toxodontia and yields a good opportunity to test current phylogenetic hypothesis, mostly based on Neogene representatives. [ABSTRACT FROM AUTHOR]

The Eocene flora of the Okanogan Highlands in the Pacific Northwest of North America has been recognized previously to include extinct species of both extant genera of the Trochodendraceae. Here, using microcomputed tomography (μCT) scanning to augment traditional methods, we recognize additional diversity, including two new fruit types. Concavistylon wehrii sp. nov. is documented by a fertile twig with attached leaves and an infructescence, allowing for an unusually complete reconstruction of this extinct genus. Concavistyon wehrii infructescences are racemes bearing fruits on short pedicels. Fruits are apically dehiscent capsules with four to six styles. The leaves resemble those of modern Trochodendron in pinnate venation, glandular teeth, and epidermal anatomy but have short petioles. The second new type of infructescence, Pentacentron sternhartae gen. et sp. nov., resembles extant Tetracentron in having small, sessile, apically dehiscent capsules but consistently has five, rather than four, styles. The μCT X-ray imaging demonstrates that fruits of both Concavistylon and Pentacentron differ from those of extant Trochodendraceae in having styles that are concave with stigmas directed inward rather than outward. These fossils, together with previously recognized fossil fruits and leaves of Trochodendron and leaves of Tetracentron from the same beds, indicate that the Trochodendraceae family was more diverse 50-52 Ma than it is today. [ABSTRACT FROM AUTHOR]

Around the early–middle Eocene boundary, the first occurrence of contourite drift sediments and widespread deep ocean erosion indicate changes in the North Atlantic ocean circulation. Interestingly, these changes coincide with the first steps of Cenozoic cooling from the Paleogene greenhouse climate towards the modern icehouse. The cause for this ocean circulation reorganization is poorly understood since modern water mass tracers may have worked fundamentally different in the past and the paleoceanographic proxy record is limited in both time and space. As a result, it is challenging to reliably reconstruct the climatic and tectonic boundary conditions e.g. atmospheric greenhouse gas concentration and the depth and geometry of developing and closing passages between ocean basins. In this study, we attempt to identify thresholds in tectonic gateway passages and atmospheric CO 2 concentration, using the fully coupled Earth System Model COSMOS . Indeed, the simulation of Earth's past climates can unravel the physical processes driving deep-water formation in a greenhouse world. Specifically, we use COSMOS to evaluate the impact of changes in the North Atlantic gateways at the early–middle Eocene boundary on the North Atlantic Deep Western Boundary Currents under low obliquity configuration. We find that Northern Component Waters start to form when the Greenland Scotland Ridge reaches a threshold depth of deeper than 200 m, while the Arctic Ocean is still shut off from the North Atlantic. In this scenario, the relatively deep Greenland Scotland Ridge allows for sufficient inflow of warm, salty Atlantic surface waters into the Nordic Seas to initiate convection during winter cooling. Opening the seaway towards the Arctic leads to a cessation of Northern Component Water formation as it allows for inflow of brackish surface waters into the northern Nordic Seas, hindering Northern Component Water formation. [ABSTRACT FROM AUTHOR]

The Ailaoshan-Jinshajiang porphyry belt located in the Sanjiang area of eastern Tibetan Plateau is one of the major polymetallic metallogenic belts in China. However, the nature and genesis of magmatic intrusions associated with the porphyry copper mineralization in this belt remain contentious. Here we focus on the Bijiashan Deposit, one of the large-scale porphyry copper deposits in this area, to gain insights on the host rock, petrogenetic mechanism, tectonic setting based on geochemistry, zircon U Pb geochronology and Lu Hf isotopic compositions. Zircon U Pb dating of the ore-hosting porphyry yielded an age of 35.6 ± 0.2 Ma. The major elements of the porphyry show wide range in SiO 2 (58.33–70%), high K 2 O (2.83–8.85%) and Na 2 O + K 2 O (mostly>8%), and moderate range in A/CNK (0.56–1.17). Our data suggest that the porphyry belongs to high-Kcalc-alkaline-alkaline and metaluminous-peraluminous series. The trace elements are characterized by enrichment in K, Rb, Ba, La and Nd, but depletion in Ta, Nb, P and Ti, and enrichment in LREE but depletion in HREE with LREE/HREE of 9.78–20.10. The main intrusion associated with mineralization corresponds to alkali-richA-type granitoid, with high TFeO (0.49–3.4%), low Na 2 O/K 2 O (0.23–1.62), and high 1000*Ga/Al (2.17–2.64 except 1.57), and right-declinedREE patterns. However, some of the geochemical features also are consitent with the typical characteristics of C-adakite rocks, including high contents of Al 2 O 3 (13.49–16.12%) and Sr (>400 ppm), lower MgO (mostly <3%), depleted Y (<18 ppm) and Yb (<1.9 ppm), and slightly negative Eu anomalies ( δEu  = 0.83). The zircon ε Hf ( t ) values show a wide range from negative to positive (−13.65 to 2.60) with T DM C varying from 947 Ma to 1982 Ma, suggesting that the Eocene porphyries were derived from the partial melting of the lower crustal materials, together with the addition of mantle source materials. Combined with the regional geological evolution, our study suggests that the ore-hosting porphyry formed under a setting of post-collisional crustal extension. Following the collision between the Indian and Eurasian plates, the stress relaxation resulted in extension and magma emplacement along major faults and the copper polymetallic mineralization formed along the Chenghai-Binchuan Fault. [ABSTRACT FROM AUTHOR]

Magmatic records with high Mg and low Y signatures provide important insights into the deep mantle dynamics that dictate the evolution of ancient orogenic belts. This paper reports the presence of felsic intrusive dikes with high Mg and low Y signatures intruding the Baingoin Batholith (central Tibet) at ca. 94 Ma. These dikes show adakitic signatures, including high Sr and low Y and Yb contents and high Sr/Y and (La/Yb) N ratios. The adakitic dacitic dikes can be grouped into high Mg (Mg# = 48–52) with positive zircon ε Hf (t) (8.3–12.4) and whole-rock ε Nd (t) (0.27) and low Mg (Mg# = 37–45) with positive zircon ε Hf (t) (7.2–13.5) varieties. These distinct geochemical features, along with geological observations, show that the Baingoin high-Mg adakitic dacitic dikes were most likely derived from the partial melting of a foundering juvenile lower crust and subsequent melt–mantle reaction, whereas the low-Mg adakitic dacitic dikes can be interpreted as resulting from the partial melting of a thickened lower crust that did not delaminate. The generation of these adakitic rhyolitic dikes can be attributed to hornblende-dominated fractional crystallization of the adakitic dacitic melts. A decrease in Y and heavy rare earth element contents of magmatic records from 120–100 Ma to 95–80 Ma within the Lhasa–Qiangtang collision zone suggest an increase in crustal thickness with time. The volumetrically minor westward-migrating high-Mg adakitic magmatism can readily be interpreted as the consequences of the westward-migrating foundering of the lithosphere triggered by Rayleigh-Taylor instabilities along the Lhasa–Qiangtang collision zone during the period 94–80 Ma. [ABSTRACT FROM AUTHOR]

A composite xenolith composed of a zircon-bearing, apatite-rich olivine-pyroxene hornblendite and an amphibole harzburgite part was found in an outcrop of Neogene alkali basalt at Szigliget, Bakony-Balaton Highland Volcanic Field, Western Hungary. The hornblendite is composed dominantly of amphibole that is strongly enriched in incompatible trace elements along with apatite, orthopyroxene and olivine. Zircon, rutile, ilmenite and sulphide occur as inclusions in the silicate minerals as accessory phases. On the basis of the chemical composition of the minerals, we estimate that the hornblendite crystallized at ~1000–1015 °C and 1.2–1.4 GPa pressure in the uppermost mantle under oxidising conditions (Δlog f O 2 (FMQ)~ + 1.3). The hornblendite precipitated from a volatile and incompatible element-rich silicate melt with trachyte or phonolite composition, which might be derived from an alkali basalt melt by high-degree (>70%) fractional crystallisation. [ABSTRACT FROM AUTHOR]

Of the isotopically distinctive mantle domains, the so-called HIMU (“high-μ”; μ =  238 U/ 204 Pb) source is the most extreme, and its genesis continues to be debated. We report very strong U enrichment at unchanged Th concentrations in Cretaceous oceanic serpentinites with exceptionally high 206 Pb/ 204 Pb (reaching 56) but unchanged 208 Pb/ 204 Pb. Similar, but less extreme, features are found in 1.9 billion years old altered oceanic crust (AOC). Forward modelling demonstrates that mantle, if metasomatised by supercritical liquids derived from AOC and serpentinites, evolves to the HIMU Pb isotope signatures, while satisfying experimental and empirical constraints on subduction zone element processing. By contrast, no model solutions for the conventional proposal of the HIMU source representing residual igneous altered oceanic crust can be reconciled with 208 Pb/ 204 Pb, strengthening the need for a paradigm shift regarding HIMU OIB genesis. Over time, the net U addition to the convecting mantle via deeply subducted serpentinite has expressed itself as the so-called second terrestrial Pb isotope paradox, or kappa conundrum. [ABSTRACT FROM AUTHOR]

Igneous activity in the rear-arc of the Paleogene Urumieh–Dokhtar Magmatic Belt of Iran has to date been poorly studied. An example of such activity, Late Eocene potassic mafic to intermediate magmatic rocks in the Lahrud area of NW Iran, is the focus of this work. These lavas include olivine-bearing clinopyroxene-phyric basalts, analcime-bearing leucite–clinopyroxene-phyric basalts, andesites, and trachytes, and Paleocene–Early Eocene pyroclastic rocks. Monzo-syenite plugs (dated here at ∼37 Ma), clinopyroxene-phyric basaltic dikes, and leucite-bearing clinopyroxene-phyric basaltic dikes intrude older lavas and pyroclastic rocks. Olivine-bearing clinopyroxene-phyric basalts and analcime-bearing leucite–clinopyroxene-phyric basalts are characterized by large phenocrysts of olivine, clinopyroxene, leucite, and analcime. Clinopyroxene-rich enclaves and partially resorbed mantle xenoliths also occur. Olivine phenocrysts are zoned from high-Mg# cores (Mg# = 90) to Fe-rich rims (Mg# = 66). Clinopyroxene phenocrysts from the olivine-bearing clinopyroxene-phyric basalts, analcime-bearing leucite–clinopyroxene-phyric basalts and clinopyroxene crystals in the enclaves show complex oscillatory zoning, sieve textures, and resorption textures, but with systematic core–rim compositional trends. Their 87Sr/86Sr isotopic compositions measured in situ range from 0·7037 to 0·7068 (mean = 0·7052 ± 0·0004), suggesting negligible crustal assimilation during fractional crystallization. The Lahrud lavas are potassic and are enriched in light rare earth elements and large ion lithophile elements such as Th, Rb, K and U. High field strength elements (HFSE), such as Nb, are depleted in the olivine-bearing clinopyroxene-phyric basalts and analcime-bearing leucite–clinopyroxene-phyric basalts, but enriched in the trachytes and trachytic ignimbrites. The isotopic compositions vary: 87Sr/86Srt from 0·7045 to 0·7052, εNd(t) from +2·8 to +3·3, and εHf(t) from +7·2 to +7·7. The rocks have radiogenic lead 206Pb/204Pb from 18·66 to 18·76, 207Pb/204Pb from 15·58 to 15·62, and 208Pb/204Pb from 38·73 to 38·81. Modeling of major and trace elements using the MELTS algorithm indicates that the geochemical variations in the basaltic to andesitic rocks are reasonably explained by shallow fractional crystallization with some complications owing to source heterogeneity, crustal assimilation, and magma mixing. The isotopic data imply that partial melting of old sub-continental lithospheric mantle was not responsible for the Lahrud potassic magmas; Hf isotopes and Zr/Nb ratios suggest derivation from an enriched mantle wedge, whereas ratios of incompatible trace elements (e.g. La/Yb, Ba/La, Ce/Pb, Th/Yb) and high 87Sr/86Sr suggest mantle metasomatized by slab-derived fluids or melts dominated by a sediment component. Geochemical modeling using the Arc Basalt Simulator version 5 reveals that the HFSE-depleted, olivine-bearing, clinopyroxene-phyric basalts originated from a high-temperature mantle wedge (2·2 GPa, 1310°C) fluxed intensively (5%) by melts from a deep hot slab (6 GPa, 1000°C). The moderately HFSE-depleted, olivine-bearing, clinopyroxene-phyric basalts reflect melting of a lower-temperature mantle wedge (2·2 GPa, 1300°C) with a lesser amount of slab melt flux (4%) from a lower temperature and shallower slab (3 GPa, 866°C). In contrast, the leucite–clinopyroxene-phyric basalts and andesites are from a similar source to the moderately HFSE-depleted, olivine-bearing, clinopyroxene-phyric basalts (3 GPa, 866°C) but with a contribution from a lower temperature mantle wedge (2·2 GPa, 1270°C). During Late Eocene times, slab retreat and upper-plate extension occurred in the rear-arc region of the Urumieh–Dokhtar Magmatic Belt. The Lahrud potassic magmas were generated from a high-temperature mantle wedge, which resulted in melting of the slab; this slab melt flux further promoted melting of the mantle wedge. [ABSTRACT FROM AUTHOR]

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Until now Darbonetus was represented by only one valid species, the type species D. aubrelongensis from the early Oligocene of the Quercy region, France. A late appearance of this genus and of its closest relative Amphidozotherium have been thought to result from dispersal from outside western Europe, rather than a local ancestry earlier in the late Eocene. Here, a new species, Darbonetus sigei sp. nov., is described from the middle Priabonian site of La Débruge, France. Although clearly closely related to D. aubrelongensis, D. sigei shows less reduction of its p2, p3, and m3 than in the more derived type species. The early age of D. sigei suggests that its origins were within the still isolated central European island and that it is unnecessary to invoke dispersal from another continent. [ABSTRACT FROM AUTHOR]

Light microscope (LM) and scanning electron microscope (SEM) investigations of palynomorphs from a mid-Eocene coal lens at the Stolzenbach brown-coal mine (“Borken brown coal field”) yielded a remarkable microflora assemblage, with 76 pollen and spore taxa, dominated by monolete fern spores. Numerous pollen and pollen clumps of Myrtaceae and Salicaceae might represent in-situ growth of these families, which were associated with pollen of Aralia -type, Eotrigonobalanus spp., Flueggea -type, Nyssa -type, three Pentapollenites taxa, and Spinaepollis spinosus , plus many others. Ericaceae such as Erica -type, Kalmia - type , and Rhododendron -type pollen are described from here for the first time; the last represents the earliest known occurrence of the genus. Additionally, five tropical south Asian Sapotaceae taxa (Mimusopeae- and Isonandreae tribes), and one tropical South American bombacoid Eriotheca -type occur. Several previously undescribed pollen taxa for the Eocene have been found; some are amongst the oldest examples of these pollen taxa: the Nuphar -type pollen represents the earliest occurrence in Europe and, whilst the Acalypha -type and Trochodendron -type are the oldest pollen occurrences in general, the Viburnum -type, affiliable to Viburnum clemesiae probably represents a tropical south Asian lineage. [ABSTRACT FROM AUTHOR]

Abstract: Stephania Loureiro is a large genus within Menispermaceae, with approximately 60 extant species naturally distributed in tropical to subtropical areas in Asia and Africa, and a few in Oceania. This genus possesses highly characteristic endocarps that facilitate identification of extant and fossil specimens. Here, we report some well‐preserved fossil fruits of Stephania from North America and East Asia. The specimens indicate the endocarps were bony or woody with an obovate to obovate‐rotund outline and a horseshoe‐shaped locule. The endocarp length varies from 4.7 to 8.3 mm, and width from 3.7 to 7.0 mm. The endocarp has a clear foramen in the central area and is surrounded by a keel with ribs running along the dorsal surface. Only one lateral crest develops on each side of the endocarp. Two new species are recognized: Stephania wilfii Han & Manchester sp. nov. from the Paleocene to Eocene of Wyoming (USA), and Stephania jacquesii Han & Manchester sp. nov. disjunct between the late Eocene of Oregon (USA) and the late Oligocene of Guangxi Province (China). In addition, on the basis of more detailed morphological comparative analyses, we transfer the fossils formerly treated as Diploclisia auriformis (Hollick) Manchester from the early Eocene of London Clay, and the middle Eocene of Alaska and Oregon to Stephania auriformis (Hollick) Han & Manchester comb. nov. These fossil materials indicate a broader biogeographic distribution for the ancestors of extant Stephania lineages. This finding enhances our knowledge of the taxonomic and morphological diversity of Stephania and provides new evidence concerning its phytogeographic history. [ABSTRACT FROM AUTHOR]

Triceratium barbadense Greville, 1861a, T. brachiatum Brightwell, 1856, T. inconspicuum Greville, 1861b and T. kanayae Fenner, 1984a, are among the most common diatoms reported worldwide from lower to middle Eocene biosiliceous sediments. Due to complicated nomenclatural histories, however, they are often confused. A morphometric analysis performed herein indicates that T. brachiatum is conspecific with T. inconspicuum, and that both were previously often misidentified as T. barbadense. Triceratium barbadense sensu stricto is a distinct species similar to Triceratium castellatum West, 1860. Triceratium brachiatum and T. kanayae are transferred herein to a new genus, Fenneria, for which a close phylogenetic relationship with Medlinia Sims, 1998 is proposed. A review of the geographic and stratigraphic distribution of Fenneria shows that the best constrained records of its occurrences are found at DSDP Site 338, and ODP Sites 1051 and 1260. The ages of the base (B) and top (T) of each species' stratigraphic range are calibrated here to the Geomagnetic Polarity Timescale either directly or inferred via correlation with dinocyst biostratigraphy. Latitudinal diachroneity of ~7 million years is documented for F. brachiata, which disappears earlier in tropical and mid-latitude sites than in the northern high latitudes. These observations, coupled with a preliminary compilation of the Chron C20n taxonomic composition of pelagic diatom assemblages for Sites 338, 1051 and 1260, indicate that diatoms diversified palaeobiogeographically considerably earlier than the Eocene-Oligocene Transition, as commonly believed. This study also emphasizes the importance of the detailed examination of specimens from both museum collections and deep-sea cores as a step toward enhancing the utility of Palaeogene diatoms in palaeoceanographic and palaeoenvironmental reconstructions. [ABSTRACT FROM AUTHOR]

PREMISE OF THE STUDY: Fossils provide minimum age estimates for extant lineages. Here we critically evaluate Cantisolanum daturoides Reid & Chandler and two other early putative seed fossils of Solanaceae, an economically important plant family in the Asteridae. METHODS: Three earliest seed fossil taxa of Solanaceae from the London Clay Formation (Cantisolanum daturoides) and the Poole and Branksome Sand Formations (Solanum arnense Chandler and Solanispermum reniforme Chandler) were studied using x-ray microcomputed tomography (MCT) and scanning electron microscopy (SEM). KEY RESULTS: The MCT scans of Cantisolanum daturoides revealed a high level of pyrite preservation at the cellular level. Cantisolanum daturoides can be clearly excluded from Solanaceae and has more affinities to the commelinid monocots based on a straight longitudinal axis, a prominent single layer of relatively thin-walled cells in the testa, and a clearly differentiated micropyle surrounded by radially elongated and inwardly curved testal cells. While the MCT scans show no internal preservation in Solanum arnense and Solanispermum reniforme, SEM images show the presence of several characteristics that allow the placement of these taxa at the stem node of Solanaceae. CONCLUSIONS: Cantisolanum daturoides is likely a member of commelinid monocots and not Solanaceae as previously suggested. The earliest fossil record of Solanaceae is revised to consist of fruit fossil with inflated calyces from the early Eocene of Patagonia (52 Ma) and fossilized seeds from the early to mid-Eocene of Europe (48-46 Ma). The new identity for Cantisolanum daturoides does not alter a late Cretaceous minimum age for commelinids. [ABSTRACT FROM AUTHOR]

A fossil species of the extant liverwort genusFrullaniaRaddi is described and illustrated, based on a single inclusion in a piece of Rovno amber (Ukraine) that shares its age with Late Eocene Baltic amber, its northern contemporary.Frullania rovnoiis characterised by leaves with a rounded dorsal lobe and the absence of ocelli. The ventral lobe is inflated and forms a saclike lobule, which is bell-shaped and somewhat constricted above the mouth. The bifid underleaves have several blunt teeth or angulations along the shoulder. The Rovno fossil differs sufficiently from morphologically similar species preserved in Baltic and Bitterfeld amber as to be described as new to science. The shape of the lobules and underleaves, as well as the absence of ocelli, indicate an affiliation toF.sect.Australes, hitherto represented in Eocene amber inclusions solely byF. schumannii(Casp.) Grolle. The Rovno fossil is distinguished from extant species ofF. subg.Australesand fromF. schumanniiby having roughly and irregularly dentate-angulate underleaf margins. [ABSTRACT FROM PUBLISHER]

Although the North Anatolian Shear Zone is one of the main lithospheric-scale strike-slip deformation zone in the world, playing a prominent role in the complex geodynamic interaction among the Eurasian, Anatolian and Arabian plates, the onset time of its activity remains highly controversial. Here, we tackle this issue by utilizing nannofossil biostratigraphy on deposits from the Taşcilar basin, a pull-apart basin that we have identified inside the North Anatolian Shear Zone overprinting the Intra-Pontide suture zone. The syn-tectonic sedimentary succession of the Taşcilar basin developed completely during the early Eocene (Ypresian; CNE4- CNE5 Zones). The strike-slip faulting related to the initial onset of the North Anatolian Shear Zone can likely be constrained within the Ypresian, suggesting that the westward escape of the Anatolian plate along the North Anatolian Shear Zone started in the early Eocene. [ABSTRACT FROM AUTHOR]

The pre-Oligocene sediment succession including shipboard lithological Units II (77.65–275.54 mbsf) and III (275.54–300 mbsf) from International Ocean Discovery Program (IODP) Hole U1435A in the northern South China Sea is characterized by greenish to dark gray sandstone and siltstone of coastal marine facies with age previously undetermined due to a lack of age-diagnostic fossils. Detrital zircon U Pb ages (9 samples) and thin sections (76 samples) from these two units, together with geochemical elements (197 samples) from Units I to III were analyzed to distinguish provenance, tectonic setting, and depositional age and environment. Petrographic study reveals that most samples are fine sandstones, mainly composed of subangular quartz (70–80%) and alkaline feldspar (10–15%; mostly K-feldspar), indicating a near proximal provenance. Discrimination diagrams, element ratios and chondrite-normalized rare earth element patterns suggest a relatively stable source of felsic rocks. Detrital zircon U Pb dating results reveal a dominance of Mesozoic ages with a pronounced Early Cretaceous peak at ~ 110 Ma. Fourteen zircon grains from 7 samples yield much younger ages between ~ 65 and 38 Ma, indicating middle to late Eocene deposition, broadly corresponding to the lacustrine-shallow neritic Enping-Wenchang Formations of the Pearl River Mouth Basin. Comparison among various elemental proxies from the Eocene sediments in Hole U1435A and in offshore industrial wells confirms a continental island arc setting in the Cretaceous when the zircons were produced. In the middle and late Eocene, these Cretaceous igneous rocks were likely the source of the sediment deposited in a coastal marine environment. The relatively minor variations in elemental distribution and the concentration of Paleogene zircons (~ 50–38 Ma) further imply a consistent supply of weathered material from this magmatic landmass during an active rifting period before the opening of the South China Sea. [ABSTRACT FROM AUTHOR]

The Eocene perissodactyl family Palaeotheriidae has traditionally been considered to be a nearly endemic European group within Equoidea, but a few palaeotheres have been reported from Asia. Here, I reanalyse a maxilla containing M1-3 from the Lunan Basin, Yunnan Province, China. This element was initially assigned to a new tapiromorph species, Lophialetes yunnanensis, but is here placed in a new genus Lophiohippus within Pachynolophinae based mainly on the absence of mesostyles, the strongly oblique metalophs, the strong development of lophodonty, parastyles overlapping metastyles of preceding teeth and situated mesial to the paracone, and the fact that M3 is longer than wide and has a large and buccally deflected metastyle. Lophiohippus differs from European Anchilophus and Paranchilophus in that the parastyles are situated mesial or even slightly lingual, rather than mesiobuccal, to the paracones, and M3 is markedly relatively larger than M1. I further reanalyse Qianohippus magicus from the Shinao Basin of Guizhou Province, China, in which the complete dentition is known. Qianohippus is characterized by a molariform P2 and non-molariform P3-4; a relatively high degree of lophodonty; the absence of mesostyles; an angular bending in the protoloph on P3-M3 and the metaloph on M1-3 at the paraconule and metaconule, respectively; and weakly developed 'metastylid' on the lower cheek teeth. A cladistic analysis supports a close relationship between Lophiohippus yunnanensis and Paranchilophus, and suggests that Qianohippus is closely related to some derived pachynolophs. The appearance of the pachynolophins Lophiohippus and Qianohippus in China supports the existence of a biogeographical connection between Europe and Asia in the Middle-Late Eocene, and the dispersal route was probably along the Tethyan microcontinents in the south. [ABSTRACT FROM AUTHOR]

The structural evolution and stratigraphic architecture of the Southern Lufeng Depression in the Pearl River Mouth Basin, South China Sea show two second-order sequences (SSQ1 and SSQ2) and nine third-order sequences (WSQ1-5 and ESQ1-4) within the Eocene rift-related successions. Based on integrated interpretations of seismic reflections, well logs and core data, five distinct tectono-stratigraphic patterns are identified: (1) the initial synrift-I sequence (WSQ1) of low tectonic subsidence, overfilled by alluvial fan or fan-delta deposits and volcanic deposits, with no clear systems tracts; (2) the climax synrift-I sequences (WSQ2–4) developed in response to rapid tectonic subsidence, generally consisting of a low-stand systems tract (LST), transgressive systems tract (TST) and high-stand systems tract (HST); (3) the late synrift-I sequence (WSQ5) characterised by a decreased tectonic subsidence rate, dominated by braided delta, deep and shallow lacustrine sediments, mainly constructed by TST and HST; (4) the early synrift-II sequences (ESQ1–2) rapidly filled by braided deltaic sandstone and mainly composed of TST and HST with less common LST units; and (5) the late synrift-II sequences (ESQ3–4), which are totally filled by braided deltaic system in a shallow-water lake setting, presenting typical imbricate clinoforms or sub-parallel seismic configurations, consisting of only TST and HST components. During the climax stage of synrift-I development, the depositional setting changed from a prominent shallow lake (WSQ2) to a deep-lucustrine with turbiditic deposits (WSQ3) and finally dominated by mostly braided deltaic-shallow lacustrine deposits (WSQ4); the HST occupies an increasing proportion from early to late. Furthermore, the stratigraphic patterns, especially LST units of the climax synrift-I stage, are significantly influenced by topographic variations and slope-break belt types in the hanging dip-slope. This study reveals that the spatial and temporal evolution of lacustrine depositional and stratigraphic patterns were significantly controlled by the interplay of tectonic subsidence and sediment supply, and provides a fundamental basis for predicting the favourable reservoirs and geometry of source rocks related to the general variability of Eocene rift-related tectonic subsidence in the Southern Lufeng Depression of the Pearl River Mouth Basin. Furthermore, the topographic responses of differential active fault-stepped patterns associated with magma intrusions, highlight the variability of relevant sequence architectures in the hanging dip-slope in lacustrine rift basins. [ABSTRACT FROM AUTHOR]

Two upper Palaeocene - lower Eocene stratigraphic sequences at the Kharga Oasis (Umm El Ghanayim and Naqb Assiut sections) were studied biostratigraphically on the basis of their calcareous nannofossil content. The investigated interval includes the upper part of the Tarawan Formation, the Tarawan Chalk, and the Esna formations. A total number of sixty-seven different taxa have been identified. The lowest occurrence (LO) of Discoaster araneus was used to place the base of the NP9b Subzone (base of Eocene) at the Gabal Umm El Ghanayim section. The lowest occurrences (LOs) of Rhomboaster bitrifida, Discoaster araneus and D. anartios are used to define the NP9a/NP9b subzonal boundary at the Gabal Naqb Assiut section. In this section, the P/E boundary is marked by a minor lithologic hiatus as indicated by the absence of the basal part of the Dababiya Member. At the studied two sections, a major turnover in calcareous nannofossil assemblages across the P/E transition was documented. The abundance of warm water Ericsonia subpertusa, Fasculithus spp., Coccolithus eopelagicus, Discoaster spp., Rhomboaster bitrifida and Tribrachiatus bramlettei characterize the Palaeocene-Eocene transition and suggest global warming and the Palaeocene-Eocene Thermal Maximum (PETM). [ABSTRACT FROM AUTHOR]

The latitudinal biodiversity gradient (LBG) is a key feature of global biodiversity, but its origin, maintenance, and future prospects remain relatively murky. Paleontological LBG studies typically adopt a genera- or species-based-perspective, rather than a functional or trait-based one. Unlike species, which are evolutionarily ephemeral, functional groups can be consistent across an entire clade's history, providing broader perspectives. To adopt a novel viewpoint on Cenozoic marine LBG drivers, we apply network analysis to Triton, a global dataset of Cenozoic macroperforate planktonic foraminiferal occurrences. We contextualized changes in functional diversity, paleo-latitudinal specialization, and community equitability, identifying: 1. specialized morphological communities in the aftermath of the Cretaceous-Paleogene (K-Pg) extinction, 2. ecological specialization of communities during the Early Eocene Climatic Optimum, 3. a severe loss in morphological community specialization due to Antarctic glaciation across the Eocene-Oligocene Transition (EOT) preceding the loss of morphological diversity by millions of years, and 4. a synchronous change in morphological specialization and richness ~19 Ma, coeval with shark extinctions. We find that the global biogeographic responses of functional communities and richness are disentangled from one another during large-scale Cenozoic climate events, revealing novel changes necessary for understanding marine ecosystems responses. Importantly, during intervals associated with global perturbations in ocean structure, such as the K-Pg and EOT, we identify multi-million year lags between functional metrics, where community-scale modifications often precede richness change. These observations highlight the need for quantifying global marine communities as detrimental changes in ocean structure continue to manifest through anthropogenic climate forcing. [ABSTRACT FROM AUTHOR]

The results of the study on diatoms revealed in Eocene deposits of the Cenozoic sequence of the Pervoocherednaya hole, which was drilled near the Southwestern Kamchatka coast, are presented. The taxonomic composition of the studied diatom assemblage including marine diatom plankton is characterized. These are the first findings of Middle Eocene planktonic diatoms having a stratigraphic value in sequences of the eastern Sea of Okhotsk region. [ABSTRACT FROM AUTHOR]

PREMISE OF THE STUDY: The plant fossil record for the neotropics is still sparse and temporally discontinuous. The location and description of new fossil material are fundamental for understanding evolutionary and biogeographic patterns of lineages. A new fossil record of Passifloraceae from the late Eocene of Colombia is described in this study. METHODS: Plant fossils were collected from a new locality from the Eocene Esmeraldas Formation. Eighteen fossil seeds were selected, described, and compared with fossil and extant angiosperm seeds based on the literature and herbarium collections. Taxonomic affinities of the fossil seeds within Passifloraceae s.l. were evaluated by comparing morphological characters of the seeds in a phylogenetic context. Stratigraphic information associated with the fossil locality was used to interpret the environment and taphonomic processes associated with fossil deposition. KEY RESULTS: A new seed fossil genus and species, Passifloroidesperma sogamosense gen. and sp. nov., is described and associated with the subfamily Passifloroideae based on the presence of a foveolate seed surface, ruminate endosperm, and a seed coat with prismatic palisade cells. The depositional environment of the locality is described as a fl oodplain associated with river channels. CONCLUSIONS: A detailed review of the Passifloraceae fossil record indicates that P. sogamosense is the oldest confirmed record of Passifloraceae. Its late Eocene age provides a minimum age that can be used as a calibration point for the crown Passifloroideae node in future dating analyses that together with its neotropical geographic location can shed light on the origin and diversification of the subfamily. [ABSTRACT FROM AUTHOR]

One hundred and thirty-six core and cuttings samples from Upper Cretaceous–Eocene deposits that are believed to include the most important source rocks in the Sirte Basin have been subjected to Rock-Eval pyrolysis, total organic carbon measurements, and palynofacies and microfacies analyses to determine palaeoenvironments and the thermal maturation history of the succession. It is apparent that the lower part of the Bahi Formation, the oldest rock unit examined, reflects a basin margin environment under the influence of freshwater input. Shallow marine, near-shore, inner shelf, suboxic–anoxic conditions, which are first suggested by the uppermost deposits of the Bahi Formation, prevailed for much of the time during deposition of the younger Cretaceous Etel, Rachmat, Sirte and Kalash formations. Shallow supratidal and intertidal sub-environments alternating with deeper environments of shelf embayments associated with a maximum rise in sea level are indicated by the Paleocene Farrud Member of the Beda Formation. The Zelten Formation consists of shallow intertidal and lagoonal facies, and the overlying Paleocene–Eocene Kheir Formation reflects relatively shallow marine sedimentation in mid to outer shelf environments alternating with short-lived, shallow, intertidal-lagoonal to supratidal conditions. The TOC content of the Upper Cretaceous samples examined is mostly moderate (up to 2.04%), the organic matter consisting of Types II and II/III kerogen. Differences in hydrocarbon generation potential are linked to varying proportions of aquatic versus terrigenous organic matter in the samples examined and hence to depositional conditions. Combined geochemical and palynofacies data reflect deposition mainly in weakly reducing to suboxic settings and suggest that immature to early mature gas-prone source rocks are within the Etel, Rachmat and some of the Sirte Formation, and mature oil/gas-prone source rocks are within the Sirte and Kalash formations. [ABSTRACT FROM AUTHOR]

the fossil woods and leaves of the Fossil Forest Piedra Chamana represent a diverse assemblage of plants dating to 39 Ma (late Middle Eocene). The fossils are preserved in an ashfall and overlying lahar deposits near the small village of Sexi in the northern Peruvian Andes (central Cajamarca). the assemblage includes dicot wood types and leaf morphotypes, as well as a diversity of monocot material. the ~30 dicot wood types are referred to the families Acanthaceae, Anacardiaceae, Apocynaceae, Combretaceae, Cordiaceae, Dipterocarpaceae, Euphorbiaceae, Fabaceae, Lechythidaceae, Lythraceae, Malvaceae, Melastomataceae, Muntingiaceae, rubiaceae, rutaceae, and Sapindaceae. Described herein are descriptions of the first 17 wood types that have been assigned to the families Acanthaceae through Lythraceae; descriptions of the additional wood types will appear in a later paper. The paleovegetation can be characterized as lowland tropical forest with a dry aspect based on preliminary analysis of floristic affinities and wood anatomical characteristics of the fossils. [ABSTRACT FROM AUTHOR]

On the high-elevation, low-relief Bogong Plateau, within the Eastern Uplands in Victoria, well-preserved diverse macrofloras and microfloras have been recovered from Eocene sediments at two sites underlying Eocene–Oligocene basalts. Estimates of mean annual temperature (MAT) were made from the floras at each site, using a novel method calculating probability density functions and maximum likelihood co-occurrence climate envelopes of the nearest living relatives of multiple fossil taxa, and the proportion of non-toothed rather than toothed leaf margins of all fossil leaves. The most likely scenario is an Eocene MAT at Bogong Plateau of 18°C, consistent with the cloudy mesothermal montane environment indicated by the abundance of tree ferns and other flora. From the MAT, the maximum Eocene paleo-elevation of the flora sites on the plateau can be calculated using the ‘lapse rate’ method, and was probably around 550−700 m above sea-level (∼1000 m lower than at present), but with large uncertainties for these estimates. The macrofloras accumulated in stream valleys, so the maximum elevation of the Eastern Uplands at the time was greater, matching other estimates of >800 m. Uplift to the present elevation probably occurredca8–4 Ma, so the alpine environment on the high plains dates to this time, and the high-altitude biota has therefore developed in the last 8 million years. [ABSTRACT FROM AUTHOR]

Wadi El-Hitan, the UNESCO World Heritage Site, of the Fayum Depression in the northeast part of the Western Desert of Egypt, has produced a remarkable collection of Eocene vertebrates, in particular the fossil whales from which it derives its name. Here we describe a new genus and species of marine catfishes (Siluriformes; Ariidae), Qarmoutus hitanensis, from the base of the upper Eocene Birket Qarun Formation, based on a partial neurocranium including the complete left side, partial right dentary, left suspensorium, two opercles, left pectoral girdle and spine, nuchal plates, first and second dorsal spines, Weberian apparatus and a disassociated series of abdominal vertebrae. All of the elements belong to the same individual and some of them were found articulated. Qarmoutus gen. nov. is the oldest and the most complete of the Paleogene marine catfishes unearthed from the Birket Qarun Formation. The new genus exhibits distinctive features not seen in other African Paleogene taxa, such as different sculpturing on the opercle and pectoral girdle with respect to that on the neurocranium and nuchal plates, denticulate ornamentation on the skull bones arranged in longitudinal rows and forming a radiating pattern on the sphenotic, pterotic, extrascapular and the parieto-supraoccipital, indentations or pitted ornamentation on the nuchal plates as well as the parieto-supraoccipital process, strut-like radiating pattern of ornamentation on the opercle from the proximal articulation to margins, longitudinal, curved, reticulate ridges and tubercular ornamentations on the cleithrum, sinuous articulation between the parieto-supraoccipital process and the anterior nuchal plate, long, narrow, and arrowhead shaped nuchal shield, very small otic capsules restricted to the prootic. Multiple parsimony and Bayesian morphological phylogenetic analyses of Ariidae, run with and without “molecular scaffolds”, yield contradictory results for the placement of Qarmoutus; the genus is either a phylogenetically basal ariid, or it is deeply nested within the ariid clade containing New World species of Sciades. [ABSTRACT FROM AUTHOR]

Through the Cenozoic, paleoclimate records show general trends of global cooling and increased aridity, and environments in North America shifted from predominantly forests to more open habitats. Paleobotanical records indicate grasses were present on the continent in the Eocene; however, paleosol and phytolith studies indicate that open habitats did not arise until the late Eocene or even later in the Oligocene. Studies of large mammalian herbivores have documented changes in ecomorphology and community structure through time, revealing that shifts in mammalian morphology occurred millions of years after the environmental changes thought to have triggered them. Smaller mammals, like rodents and lagomorphs, should more closely track climate and habitat changes due to their shorter generation times and smaller ranges, but these animals have received much less study. To examine changes in smaller mammals through time, we have assembled and analyzed an ecomorphological database of all North American rodent and lagomorph species. Analyses of these data found that rodent and lagomorph community structure changed dramatically through the Cenozoic, and shifts in diversity and ecology correspond closely with the timing of habitat changes. Cenozoic rodent and lagomorph species diversity is strongly biased by sampling of localities, but sampling-corrected diversity reveals diversity dynamics that, after an initial density-dependent diversification in the Eocene, track habitat changes and the appearance of new ecological adaptations. As habitats became more open and arid through time, rodent and lagomorph crown heights increased while burrowing, jumping, and cursorial adaptations became more prevalent. Through time, open-habitat specialists were added during periods of diversification, while closed-habitat taxa were disproportionately lost in subsequent diversity declines. While shifts among rodents and lagomorphs parallel changes in ungulate communities, they started millions of years earlier than in larger mammals. This is likely a consequence of the smaller mammals' greater sensitivity to environmental changes and more rapid evolution. These results highlight the importance of examining understudied members of vertebrate faunas for understanding the evolution of terrestrial communities through time. [ABSTRACT FROM AUTHOR]

The nightshade family Solanaceae holds exceptional economic and cultural importance. The early diversification of Solanaceae is thought to have occurred in South America during its separation from Gondwana, but the family’s sparse fossil record provides few insights. We report 52.2-million-year-old lantern fruits from terminal-Gondwanan Patagonia, featuring highly inflated, five-lobed calyces, as a newly identified species of the derived, diverse New World genus Physalis (e.g., groundcherries and tomatillos). The fossils are considerably older than corresponding molecular divergence dates and demonstrate an ancient history for the inflated calyx syndrome. The derived position of these early Eocene fossils shows that Solanaceae were well diversified long before final Gondwanan breakup. [ABSTRACT FROM AUTHOR]

An isolated, yet virtually intact contour feather ( FUM-1980) from the lower Eocene Fur Formation of Denmark was analysed using multiple imaging and molecular techniques, including field emission gun scanning electron microscopy ( FEG- SEM), X-ray absorption spectroscopy and time-of-flight secondary ion mass spectrometry (ToF- SIMS). Additionally, synchrotron radiation X-ray tomographic microscopy ( SRXTM) was employed in order to produce a digital reconstruction of the fossil. Under FEG- SEM, the proximal, plumulaceous part of the feather revealed masses of ovoid microstructures, about 1.7 μm long and 0.5 μm wide. Microbodies in the distal, pennaceous portion were substantially smaller (averaging 0.9 × 0.2 μm), highly elongate, and more densely packed. Generally, the microbodies in both the plumulaceous and pennaceous segments were aligned along the barbs and located within shallow depressions on the exposed surfaces. Biomarkers consistent with animal eumelanins were co-localized with the microstructures, to suggest that they represent remnant eumelanosomes (i.e. eumelanin-housing cellular organelles). Additionally, ToF- SIMS analysis revealed the presence of sulfur-containing organics - potentially indicative of pheomelanins - associated with eumelanin-like compounds. However, since there was no correlation between melanosome morphology and sulfur content, we conclude these molecular structures derive from diagenetically incorporated sulfur rather than pheomelanin. Melanosomes corresponding roughly in both size and morphology with those in the proximal part of FUM-1980 are known from contour feathers of extant parrots (Psittaciformes), an avian clade that has previously been reported from the Fur Formation. [ABSTRACT FROM AUTHOR]

The stratigraphic succession in the Cikola Canyon (part of the North Dalmatian Foreland Basin) was studied in detail to describe both the sedimentological characteristics and fossil assemblages of the Lower Eocene deposits during the initial stage of the foreland basin formation. The North Dalmatian Basin now represents a part of the Outer Dinarides, and was developed in front of the evolving Dinaric structures by tectonic deformation and marine transgression of an emerged and denuded Mesozoic Adriatic Carbonate Platform (AdCP). During the initial phase, a distal ramp of a foreland basin was formed, characterised by carbonate sedimentation, lasting until the Middle Eocene. In a studied section more than 300 m thick, porcelaneous foraminifera, Alveolina, Orbitolites and complex miliolids (Idalina, Periloculina) prevail, associated with conical agglutinated forms, nummulitids and red algae. These samples belong to the SBZ 11-12 (Ypresian), according to occurrences of Alveolina decastroi, Alveolina cremae, Alveolina multicanalifera and Coskinolina liburnica. Two main lithological units have been described: 1) mudstones to wackestones with sporadic occurrences of ostracods and charophyceae, deposited in restricted lagoonal settings with several episodes of freshwater influences, and 2) foraminiferal packstones to grainstones with complex miliolids, alveolinids, corallinacean algae and nummulitids, deposited within inner and middle ramp settings. Palaeogene deposition of ramp carbonates in the Outer Dinarides area was mainly controlled by the continuous compressional tectonics, and the deposits today appear in more or less discontinuous outcrops. Palaeogene transgression occurred at different times over various parts of the former carbonate platform area, and subsequent carbonate sedimentation was characterised by deposition in similar environments during different time intervals over spatially restricted carbonate ramps controlled by synsedimentary tectonics. [ABSTRACT FROM AUTHOR]

Even though African rain forests display high levels of local species diversity and endemism, their lower continental species diversity when compared with the Neotropics and Asia is paradoxical. This disparity is mainly thought to be linked to either important extinction events during the Pleistocene or at the Eocene-Oligocene boundary. African rattans or climbing palms are one of the most diverse clades of palms in Africa, representing one-third of all known species. Here, we reconstruct the phylogeny and temporal evolution of African rattans (Arecaceae: Calamoideae: Lepidocaryeae: Ancistrophyllinae) to test the two main hypotheses of palm evolution in Africa. We constructed a near-complete, dated species-level phylogenetic tree for subtribe Ancistrophyllinae using plastid and nuclear markers. The generic relationships between Ancistrophyllinae were fully resolved and species-level relationships are well to weakly supported. Ancistrophyllinae diversified during the Eocene with most species originating during the late Miocene after 10 Mya. This result is in agreement with several other studies suggesting a pre-Pleistocene origin of the extant African flora. Ancistrophyllinae display an anti-sigmoidal lineage-through-time plot with a moderate overall extinction fraction. Our simulations suggest important roles for an ancient extinction event at the Oligocene-Eocene boundary. In contrast, the hypothesis of an important extinction event in palms during the late Pliocene at 3 Mya is not supported. We suggest that the evolutionary history of African rattans has undergone a constant diversification rate punctuated by one or several important extinction events during the first part of the Cenozoic with most species diversity accumulating during the late Miocene and Pliocene. [ABSTRACT FROM AUTHOR]

A paguroid, Lessinipagurus vasjamikuzi sp. nov., is described from Eocene (upper Bartonian-lower Priabonian) of Istria, on the basis of a single right chela from Gračišće near Pazin, western Croatia. The specimen originates from beds of olistostrome breccias that formed in a bathyal setting. In addition, a new genus, Prexylopagurus, accommodated in the new family Xylopaguridae, is erected; based on a distinctive set of characters of the dorsal carapace, chelae, and operculate tergite of sixth abdominal somite. The phylogenetic relationships of the new family Xylopaguridae are discussed; it appears to have originated in the Tethyan Realm, possibly as early as the Jurassic, and displays a Tethyan distribution during the Cenozoic. Three extant species are transferred to the new genus, resulting in three new combinations: Prexylopagurus anthonii, P. philippinensis, and P. caledonicus. The palaeoecology and palaeobiogeography of the newly erected taxa are discussed. The bloom of diversity of Lessinipagurus during the late Eocene parallels the evolution and subsequent ecological expansion of grasses, especially of reed and bamboo, thus constituting a rare example of coevolution between land plants and marine organisms. The holotype of Lessinipagurus vasjamikuzi sp. nov. shows remains of an interesting syn-vivo balanomorph association; this is the earliest record of such barnacles on a decapod crustacean in the fossil record, and the sole record from an anomuran to date. [ABSTRACT FROM AUTHOR]

Since the discovery of the megaherbivore Arsinoitherium zitteli Beadnell (early Oligocene of Egypt), the extinct order Embrithopoda has remained an enigmatic group, with disputed affinities among ungulates. In this study, new specimens of Palaeoamasia kansui from the early Palaeogene of Turkey are described and a synthetic dental terminology is proposed for embrithopods. Based on 130 cranial-mandibular and dental characters, the first phylogenetic analysis of embrithopods is carried out in aim to enhance the position of Palaeoamasia within embrithopods. The monophyly of Embrithopoda is confirmed, following the topology ( Phenacolophus ( Namatherium ( Arsinoitheriinae, Palaeamasiinae))). However, phylogenetic relationships between Eurasian embrithopods ( Palaeoamasiinae: Palaeoamasia, Crivadiatherium and Hypsamasia) remain unresolved. The integration of all embrithopod genera within a cladistic analysis encompassing a wider taxonomic sample ( Condylarthra, Afrotheria/ Paenungulata and Laurasiatheria) also supports Embrithopoda as being monophyletic, but questions the position of both Phenacolophus and Namatherium within Embrithopoda. Finally, possible faunal exchange events are proposed based on three hypothesized scenarios between Eurasia and Arabia- Africa during the early Palaeogene. [ABSTRACT FROM AUTHOR]

Arc-related rocks of the Yüksekova Complex extend from Kahramanmaraş to Hakkari throughout the Southeast Anatolia representing the remnants of the Southern Branch of Neotethys. The volcanic members of this zone from the eastern parts of Lake Van suggest three different types of rock chemistry; tholeiitic (type I), calc-alkaline (type II) and alkaline (type III). Tholeiitic and calc-alkaline members suggest a subduction-related environment with their HFS and LIL element distributions. RE and trace element systematics and modelings indicate that i) the intermediate and the felsic calc-alkaline rocks are the result of fractional crystallization from a basic endmember, ii) alkaline members have originated from enriched mantle source relative to the tholeiitic and calc-alkaline lavas. Overall data from Yüksekova Complex suggest a mature supra-subduction zone environment within the southern Neotethyan Ocean during Upper Cretaceous time. The existence of Lutetian OIB like asthenospheric lavas at the upper parts of the ophiolitic assemblage in the eastern parts of Lake Van proposes the end of the normal ophiolite formation and the possible continuation of the magmatism with OIB like lavas during Middle Eocene. [ABSTRACT FROM AUTHOR]

Species in the genus Corethrella Coquillett, the only genus in the family Corethrellidae, feed on the blood of frogs and toads and are unique among Diptera in locating their hosts by sound. Their fossil record goes back to the Cretaceous and comprises seven previously described species from various amber deposits. Herein, we present the first records of Corethrella from Late Eocene Rovno amber (35 Ma), with the description of two new species: Corethrella sontagae sp.n. based on a single male, and Corethrella rovnoensis sp.n. based on a single female. A revised key to fossil species of Corethrella is given. Phylogenetic relationships within Corethrella are investigated based on Bayesian and parsimony analysis, including the new data. All species groups recognized by Borkent (2008) are recovered as monophyletic, with the exception of the drakensbergensis group, which is found to be a paraphyletic grade. Both of the newly described species can be accommodated within modern species groups: C. sontagae shows affinities with the quadrivittata group and C. rovnoensis with the rotunda group. This published work has been registered in ZooBank, . [ABSTRACT FROM AUTHOR]