Middle-Upper Miocene Research Articles

A fossil dreamer of the genus Oneirodes (Lophiiformes: Ceratioidei) from the Miocene of Sakhalin Island, Russia

AbstractThe almost complete skeleton of a fossil dreamer, identified as Oneirodes sp., is described from the middle–upper Miocene Kurasi Formation of southern Sakhalin Island, Russia. This is the second fossil skeletal record of oneirodid anglerfishes following those described from the Puente Formation of California, USA. The new specimen possesses morphological features very similar to those of the recent and fossil members of its genus, and cannot be separated from them at the species level. This finding confirms the idea of the high level of speciation of this fish family prior to the middle–late Miocene and demonstrates the wide geographic distribution of the genus Oneirodes already at this time.

Büyük Menderes Granbeni'nin Rolling Hinge (Yuvarlanan Reze) Modelinde Supra-Detachment (Sıyrılma Üstü) Havzadan Rift Havzasına Evrimi

Two types of basins developed in the Western Anatolian extensional tectonic system during the Miocene- Quaternary interval, supra-detachment and rift basins, in the form of a rolling-hinge mechanism. In this study, stratigraphic and structural data on the presence of a rolling-hinge model in the area between Buharkent-Buldan on the northern edge of the Buyuk Menderes Graben are presented for the first time and the geological evolution of the graben is discussed. In the light of obtained field data, the Miocene-Quaternary sequences deposited on the northern edge of the Buyuk Menderes Graben were evaluated under 4 main sedimentary packages, which are separated from each other by angular and/or intrabasinal unconformities. These are the Lower-Middle Miocene (1st Package) and the Middle-Upper Miocene (2nd Package) which were deposited in the supra-detachment basin, and the Plio- Quaternary 3rd and 4th packages formed in the rift basin. The structural elements that provide the basin formation and deformation of the region are the Miocene Buyuk Menderes Detachment Fault, the Pio-Quaternary Gokdere Fault, and the Holocene Buharkent Fault Segment that cuts the youngest graben basin-fill located in the most eastern part of the Buyuk Menderes Fault System. The main fault contacts of the supra-detachment basins characterizing the Miocene period are represented by a structural boundary of gneisses and schists belonging to the Menderes Massif, which is a relict of the effective compressional tectonic products of the Eocene–Oligocene interval. Due to the effectiveness of low-angle faults in the Menderes Massif until the end of Pliocene, a high rate of extension occurred; because of this, the crust thickness was reduced. As a result of cooling of the crust during Quaternary, the supra-detachment basin system was replaced by a rift system and the Menderes Massif was divided into blocks along the high-angle boundary faults of the rift basin. Field observations and kinematic analysis reveal that tectonic structures on the northern margin of the Buyuk Menderes Graben evolved from low-angle to high-angle normal faulting, and were rejuvenated southward parallel to the basin propagation in a rolling-hinge model. Thus, the basin formation also evolved from being supra-detachment to the rift type.

Sedimentology of a transgressive middle-upper Miocene succession filling a tectonically confined, current dominated seaway (the Logudoro Basin, northern Sardinia, Italy)

The sedimentary dynamics of modern current dominated seaways are well known, based on the monitoring of movement of large sand bodies over short time-scales and the geophysical reconstruction of millennial time-scale processes from recent subsurface successions. Analogues from the ancient record are less common and the longer-term (geological time-scale) sedimentary dynamics of such systems is still not properly assessed or understood. In this work, we review the interpretation of a Serravallian sand-rich stratigraphic interval (namely, the ‘Sabbie di Florinas’ Fm), variously exposed in the Logudoro Basin, a Miocene 10 km-wide and 20 km-long, tectonically-confined extensional depression, developed as a segment of the wider Sardinian Graben System, Italy. The basin includes three main depositional sequences separated by regional-scale unconformities and encompassing the middle Burdigalian to the late Messinian. The intermediate sequence, Serravallian-Tortonian in age, is the one that records the onset of the marine connection between two small basins (i.e., the Logudoro to the south and the Porto Torres to the north), which were previously isolated, resembling endorheic conditions. The oceanographic opening of a seaway, at the beginning of a regional-scale marine transgression, is firstly suggested by facies indicating a strong current reworking of sediment transiting along submerged deltaic platforms, where cross-bedded vertically stacked m-thick sandstone intervals prevail. These deposits correspond with large-scale cross-bedded sand bodies in the axial part of the seaway, where energetic currents promoted the migration of bedforms (i.e., bars and subaqueous dunes). The overlying deposits, accumulated during a late stage of transgression, show an increased maturity of textural and grain size features and exhibit herringbone cross bedding, reactivation surfaces and lamina bundles indicative of a clear tidal signature. At this stage, the seaway experienced a more mature oceanographic setting, governed by bi-directional and rotatory current patterns oriented roughly parallel to the elongation axis. Carbonate-rich large-scale bedforms (i.e., ridges) developed during this late stage of open-marine circulation, inferring possible conditions for sediment starvation in the basin. This work reconstructs the depositional scenario of a segment of the wider Sardinian Seaway, which intermittently connected isolated basins along the Sardinian Graben System. Moreover, the data discussed in this paper help in unravelling the complex sedimentary dynamics of ancient seaways and highlight their relevance for even more accurate palaeogeographic reconstructions.

A Fossil Melamphaid Fish of the Genus Scopelogadus (Teleostei: Melamphaidae) from the Neogene Deposits of Sakhalin Island, Russia

The skeleton of a berycomorph fish of the Melamphaidae family was found in sediments of the Middle-Upper Miocene of the Kurasi Formation of Sakhalin Island, Russia. Morphological features, such as a short tall body with a large head, the presence of one dorsal fin with a short base, 19 principal caudal rays, a small number of vertebrae, and single-row jaw teeth in combination with very large cycloid scales enable the assignment of this fossil to the modern genus Scopelogadus. This is the second known record of a fossil skeleton for both the genus Scopelogadus and the family Melamphaidae. The fossil locality is placed approximately 17 degrees north of the range of extant species of the genus. The presence of scopelogadus fish in the Kurasi Formation complex suggests that the accumulation depth of its deposits was at least 200 m.

Geological Features and Physical and Mechanical Properties of the Gorgoglione Building Stone of Basilicata (Southern Italy)

Since prehistoric times stones have been widely employed in the construction of historic buildings, floors, and claddings in rural and urban areas. Among the Italian natural stones, the sandstone belonging to the Gorgoglione Formation, known as the Gorgoglione Stone, quarried and worked near the homonymous village in Basilicata (Southern Italy), is usually used as a building material. The Gorgoglione Stone consists of well-cemented turbidite sandstones deposited in a Middle–Upper Miocene thrust-top basin unconformably resting on the external nappes of the Southern Apennine thrust belt. In the Gorgoglione area, it can be observed in either numerous natural outcrops or quarries. This study aims to highlight the geological peculiarities of the Gorgoglione Stone and, in particular, it is focused on its mechanical characterization for assessing the most effective use when employed in construction, such as public and civil buildings, road construction, paving, and small works of art. Based on the experimental results, obtained by samples collected from different quarries, axial stress–strain curves have been plotted, whose analysis has delivered the deformation behavior and the strength characteristics of the stone. The elastic modulus, uniaxial compressive strength, and axial strain at stress peak have been estimated for several specimens. The measured values are typically of a medium–high-strength sandstone. The tested specimens of sandstone exhibit a typical behavior of an elastic-brittle rock, characterized by a linear path and a failure typically of axial splitting. With regard to the results of the physical tests, they showed that the analyzed sandstone is characterized by quite low density and by medium–high porosity and water absorption.

Geochemistry of the middle-upper Miocene Bathan Formation, Al-Rehaili area, Jeddah, Saudi Arabia: provenance, tectonic setting, and paleoweathering implications

The present work investigates geochemical and mineralogical signatures preserved in the fluvio-lacustrine sediments of the middle-upper Miocene Bathan Formation at Al-Rehaili area, northern Jeddah, Saudi Arabia to constrain the composition and tectonic setting of the source area and to appraise the influence of weathering. Sixteen sediment samples were collected from the lacustrine delta plain and delta front sandstones (SS I), lacustrine offshore mudrocks, and the younger fluvial channel sandstones (SS II). The sandstones are compositionally immature first cycle. The sandstones (SS I) and the mudrocks of the first depositional stage were derived from an intermediate igneous source rock, whereas the sandstones (SS II) of the second depositional stage were derived mainly from a felsic igneous source rock with subordinate contribution from an intermediate igneous source rock. They indicate an active continental margin to oceanic arc tectonic setting. The values of the Chemical Index of Alteration (CIA) and the Plagioclase Index of Alteration (PIA) as well as the Al2O3/Na2O, Rb/Sr, and Al2O3/(CaO+Na2O) ratios indicate that the source rocks experienced low to moderate degree of weathering consistent with arid to semi-arid climate that prevailed during the Miocene. Subaerially exposed lacustrine offshore mudrocks displayed excessive depletion in the concentration of mobile elements comparing to the bedrock. The low values of the paleoweathering indices are further explained by the enhanced uplift of the Red Sea Escarpment after the cessation of the first stage of the Red Sea floor spreading at 14–15 m.y. ago.

Exhalative deposits in eocene volcano-sedimentary rocks in the middle part of the Urumieh-Dokhtar magmatic belt: Detailed evidence from nabar deposit, west of Kashan, Urumieh – Dokhtar Magmatic Belt

Meso-Cenozoic magmatic belt of Urumieh–Dokhtar resulted from subduction of Neothetys oceanic crust beneath the Central Iran Block with Gondwanic signature is dominated by calc-alkaline to alkaline igneous rocks. The magmatic rocks has mainly occurred in submarine environments as volcanic-volcanoclastics with interlayers of sedimentary rocks in the Eocene, while it has occurred as intrusive and subvolcanics in the Neogene. In the Nabar area volcano-sedimentary rocks of Eocene have been covered unconformably by Oligo-Miocene sedimentary rocks (Qom Formation). The Eocene and Oligo-Miocene sequences are intruded by Middle-Upper Miocene intrusive and subvolcanic bodies. Igneous rocks of Eocene and Middle-Upper Miocene are of I-type and calc-alkaline belonging to arc and post-collisional setting of continental margin, respectively. The mineralization consists of pyrrhotite, pyrite, minor chalcopyrite and sphalerite, mainly hosted by Eocene volcanoclastics and particularly by the contact metamorphic halos of Qom formation. Irregular veinlets (stringer zone) in the lower part change to massive lenses upward which conformable with Eocene enclosing rocks, and have sharp contact with overlying Qom formation. Low grad ores with irregular shape (patches, veinlets, cavity and fracture filling) which are resulted from remobilization of previous mineralization, occurred within the contact metamorphic halos of Middle-Upper Miocene intrusions. According to geochemical analysis and mineralogical studies, iron, copper, gold, silver, arsenic, lead and zinc are enriched in the ore zone. Two types of fluid inclusion (L-V and L-VS) were distinguished in quartz veinlets. The homogenization temperature and salinity of fluid inclusions vary from 121 °C – 537 °C and 9–45 wt% NaCl equivalent, respectively. These data indicating the mixing of magmatic water with meteoric water in the later stage of mineralization. The δ34S values of pyrite and pyrrhotite which varies from 10.5 to 11.6 wt% compatible with massive sulfide and skarn type deposits. Field observations, mineralogical, geochemical, fluid inclusion and isotopic data suggest that, the Nabar deposit is probably a Kuroko type massive sulfide deposit which has been partly changed to skarn during penetration of Middle-Upper Miocene subvolcanic intrusions. The Kuroko type barite deposit of Dorreh and exhalative Mn deposit of Venarch and Shahrestanak were formed at the same time, within the Eocene volcanoclastic sequences.

Clockwise paleomagnetic rotations in northeastern Iran: Major implications on recent geodynamic evolution of outer sectors of the Arabia-Eurasia collision zone

In this study, an extensive paleomagnetic sampling (70 sites) was carried out in north-eastern Iran with the aim of reconstructing the rotation history of the outer margin of the Eurasia-Arabia collision area represented by the Ala-Dagh, Binalud and Kopeh-Dagh mountain belts. We sampled the red beds units from the Lower Cretaceous Shurijeh Fm. and from the Middle-Upper Miocene Upper Red Fm (URF). Paleomagnetic results from all the sampled areas show a homogeneous amount of CW rotations measured in the above-mentioned Formations. These paleomagnetic results suggest that the oroclinal bending process that caused the curvature of Alborz mountain belt in north Iran after the Middle-Late Miocene, also extended to the Ala-Dagh, Binalud and Kopeh-Dagh mountain belts, at the north-eastern border of the Arabia-Eurasia deforming zone.Based on our paleomagnetic results and on GPS, seismological, geomorphological and structural data available in the area, a hypothesis of tectonic evolution of the northern Iran-South Caspian Basin area, from Middle-Late Miocene to Present, is here proposed. In this model, the initiation of the oroclinal bending processes in northern Iran occurred about 6–4 myr ago, related to the impinging of North Iran between the South Caspian block and the southern margin of the Turan platform, driven by the northward subduction of the South Caspian basement under the Aspheron-Balkhan Sill. As paleomagnetic results from this study show a pattern of vertical axis rotations that is inconsistent with the present-day kinematics of the northern Iranian blocks as described by seismicity and GPS data, we suggest that the tectonic processes responsible for the bending of northern Iran mountain chains are no longer active and that the westward motion of the South Caspian basin, and therefore the initiation of opposite strike-slip motion along the Ashk-Abad and Shahrud faults, occurred very recently (∼2 My ago). We therefore propose that initiation of the northward subduction of the South Caspian basin below the Apsheron-Balkhan Sill and the westward extrusion of the South Caspian block did not occur at the same time, with the former occurring between the late Miocene and the Pliocene, and the latter during the Pleistocene.

Perkembangan Fasies Sedimen Formasi Mamberamo Berumur Miosen Akhir-Pliosen di Cekungan Papua Utara

North Papua Basin is a fore arc basin located in northern coastal of Papua Island. This basin filled by Middle-Upper Miocene turbidite sediment and overlied by Upper Miocene – Quarternary clastic sediment. Upper Miocene – Quaternary clastic sediments (Mamberamo Formation) composed by interbedding conglomerate, sandstone and shale as molasses deposit. A detailed stratigraphic study was performed to identify facies and its association of the Mamberamo Formation to that give a new perspective on the characteristics and development of facies succession of Lower Mamberamo Formation. Result shows that the Lower Mamberamo Formation consists of three facies: A) cross bedding sandstone (subtidal), B) heterolothic silty shale (intra-tidal), C) carbonaceous shale (supra-tidal) deposited on Late Miocen to Plio-Pleistocene during centra range orogeny (syn-orogeny) as molasses deposits.Keywords: Fore arc basin, North Papua Basin, Mamberamo Formation, molasse deposits.

Perkembangan Fasies Sedimen Formasi Mamberamo Berumur Miosen Akhir-Pliosen di Cekungan Papua Utara

North Papua Basin is a fore arc basin located in northern coastal of Papua Island. This basin filled by Middle-Upper Miocene turbidite sediment and overlied by Upper Miocene – Quarternary clastic sediment. Upper Miocene – Quaternary clastic sediments (Mamberamo Formation) composed by interbedding conglomerate, sandstone and shale as molasses deposit. A detailed stratigraphic study was performed to identify facies and its association of the Mamberamo Formation to that give a new perspective on the characteristics and development of facies succession of Lower Mamberamo Formation. Result shows that the Lower Mamberamo Formation consists of three facies: A) cross bedding sandstone (subtidal), B) heterolothic silty shale (intra-tidal), C) carbonaceous shale (supra-tidal) deposited on Late Miocen to Plio-Pleistocene during centra range orogeny (syn-orogeny) as molasses deposits.Keywords: Fore arc basin, North Papua Basin, Mamberamo Formation, molasse deposits.

Perkembangan Fasies Sedimen Formasi Mamberamo Berumur Miosen Akhir-Pliosen di Cekungan Papua Utara

North Papua Basin is a fore arc basin located in northern coastal of Papua Island. This basin filled by Middle-Upper Miocene turbidite sediment and overlied by Upper Miocene – Quarternary clastic sediment. Upper Miocene – Quaternary clastic sediments (Mamberamo Formation) composed by interbedding conglomerate, sandstone and shale as molasses deposit. A detailed stratigraphic study was performed to identify facies and its association of the Mamberamo Formation to that give a new perspective on the characteristics and development of facies succession of Lower Mamberamo Formation. Result shows that the Lower Mamberamo Formation consists of three facies: A) cross bedding sandstone (subtidal), B) heterolothic silty shale (intra-tidal), C) carbonaceous shale (supra-tidal) deposited on Late Miocen to Plio-Pleistocene during centra range orogeny (syn-orogeny) as molasses deposits.Keywords: Fore arc basin, North Papua Basin, Mamberamo Formation, molasse deposits.

Perkembangan Fasies Sedimen Formasi Mamberamo Berumur Miosen Akhir-Pliosen di Cekungan Papua Utara

North Papua Basin is a fore arc basin located in northern coastal of Papua Island. This basin filled by Middle-Upper Miocene turbidite sediment and overlied by Upper Miocene – Quarternary clastic sediment. Upper Miocene – Quaternary clastic sediments (Mamberamo Formation) composed by interbedding conglomerate, sandstone and shale as molasses deposit. A detailed stratigraphic study was performed to identify facies and its association of the Mamberamo Formation to that give a new perspective on the characteristics and development of facies succession of Lower Mamberamo Formation. Result shows that the Lower Mamberamo Formation consists of three facies: A) cross bedding sandstone (subtidal), B) heterolothic silty shale (intra-tidal), C) carbonaceous shale (supra-tidal) deposited on Late Miocen to Plio-Pleistocene during centra range orogeny (syn-orogeny) as molasses deposits.Keywords: Fore arc basin, North Papua Basin, Mamberamo Formation, molasse deposits.

A new scenario for the mass transport deposits west Canary volcanic province

A new temporal history of mass wasting processes for the west of the Canary volcanic province is presented. Its onset has been estimated in the middle–upper Miocene (∼13.5 ± 1.2 Ma), matching with a critical period of construction for this volcanic province. Seismic profiles show an emplacement longevity (from the Miocene to Quaternary) in multiple events, defined by stacked lobes of debrites, linked to the flank collapses and volcanic avalanches of the volcanic edifices (islands and seamounts). An evolution of pathways and source areas has been detected from east (Miocene) to west (Quaternary); as well as a migration of the activity to the northwest (west of the Canary Islands: e.g. El Hierro and La Palma). Six connected branches (I–VI), three of them described for the first time here, of Quaternary seismic units of mass transport deposits (MTDs) have been characterized. The Pleistocene makes up a huge buried MTDs system, until now unknown, pointing a new mass transport sedimentological scenario. Finally, the two southernmost branches (V–VI), up to now unknown, are a mainly buried system of stacked and terraced lobes of debrites sourced mainly from the flank collapses of the volcanic seamounts of the Canary Island Seamount Province, apparently inactive from upper Cretaceous.

Evidence for the existence and diversification of a new group of cichlids in the Miocene lakes of the Tugen Hills, Kenya

Evidence for the existence and diversification of a new group of cichlids in the Miocene lakes of the Tugen Hills, Kenya

Sedimentology of a wave-dominated and tide-influenced deltaic system, upper Middle Miocene, southwestern Ulleung Basin, Korea

Abstract Integrated sedimentological and ichnological study of the gas-bearing, upper Middle Miocene strata in the southwestern Ulleung Basin has identified five main lithofacies, arranged in order from offshore and offshore transitional environments to coastal-plain channel settings. In each of repeated successions, the basal mudstone-dominated, offshore to offshore transitional facies are sharply overlain by upper shoreface sandstones that are, in turn, erosively overlain by distributary channel sandstones. In the open-marine environment, interbedded storm and interstorm deposits are predominant with sporadic flood-event beds containing a navichnia trace-fossil suite. Bioturbation style in this facies tends to reflect depositional energy variations, alternating between dwelling structures in the storm beds and feeding and grazing trace-fossil assemblages in the interstorm beds. In the channel deposits, flood-interflood couplets are commonly expressed as cross-bedded, almost non-bioturbated sandstones that alternate with bioturbated, tidally-formed, interbedded sandstone and mudstone. From this, the co-existence of storm-wave and tide-generated structures in the studied interval suggests that the depositional environment is a wave-dominated and tide-influenced deltaic setting, with the recorded tidal influence restricted to the channels, which have a higher level of heterogeneity because of tidal sedimentation during periods of low river discharge. Stratigraphically, the 400-m thick, upper Middle Miocene section shows an overall, coarsening-upward succession, representing 3rd-order falling-stage to lowstand deposits as a result of long-term basinal uplift. This succession can, in turn, be broken into four, 4th-order stratigraphic packages, each of which comprises a transgressive (T)-regressive (R) succession that is separated by a transgressive surface. These packages can be further subdivided into small-scale, upward-coarsening successions (5th-order stratigraphic packages of parasequence scale). Each small-scale succession is sharply overlain by offshore mudstone which reflects a rapid vertical facies transition, representing a marine flooding surface. Internally, each parasequence is characterized by a progradational facies succession wherein offshore mudstones are erosively overlain by upper-shoreface sandstones, forming sharp-based shoreface deposits that are likely to be produced during a forced regression, an interpretation supported by the presence of an omission trace-fossil suite on the erosion surface. In this context, the high-frequency parasequences represent short-term relative sea-level falls superimposed on the longer-term falling sea level due to a compressional tectonic regime.

Massive middle Miocene gypsic paleosols in the Atacama Desert and the formation of the Central Andean rain-shadow

The Central Andes of South America are one of the highest and broadest mountain ranges on earth and have a profound influence on climate in the Southern Hemisphere. Yet, the timing of Andean uplift and its subsequent impact on atmospheric circulation is not well known. Here we use fossil soils from along an 800-km transect (19–25°S) in the Atacama Desert of northern Chile to identify the initiation of extreme aridity along the west coast of South America and infer a minimum age for the development of the Central Andean rain-shadow. Paleosols record the onset of extreme aridity at the boundary between the middle and late Miocene (12–10 Ma). Lower Miocene (24–20 Ma) soils are chemically weathered and contain soil carbonate, indicative of a vegetated landscape and semi-arid climate. In contrast, gypsum dominates massive (2–5 m thick) upper middle Miocene soils that formed on a hyperarid landscape devoid of vegetation. The development of extreme hyperaridity is linked to the formation of the Central Andean rain-shadow through the divergence of oxygen isotope values. Oxygen isotope values of lower Miocene soil carbonates in the Atacama Desert (−5.0±1.1‰ VPDB) and Central Andes (−7.8±1‰) are similar, indicating no or a limited rain-shadow. By 15 Mya, however, δ18O values of soil carbonate differ by ∼8‰, with values of soil carbonate in Altiplano paleosols getting lower due to uplift while soil carbonate values in the Atacama Desert get higher due to aridity. Therefore, by 15 Mya there is clear evidence for a rain-shadow from the Central Andes. By the latest middle Miocene (ca. 12–10 Ma), paleosols in the Altiplano decreased to −11.8±1.0‰ while soils in the Atacama Desert increase to +1.5±4.5‰. This almost 14‰ divergence in the δ18O values of soil carbonate for soils only ∼250 km apart is evidence of a strong Central Andes rain-shadow effect in place during the late middle Miocene (12–10 Ma).

Petroleum system of Miocene troughs of the Pannonian Basin in southern Hungary, based on 3D basin modeling

The role of the Middle-Upper Miocene source rocks in the Late Neogene petroleum system of the Pannonian Basin is undoubtedly significant, but it is not entirely understood. Only a few general publications exist that describe these sediments and their importance. We have focused on understanding the Neogene tectono-stratigraphic development and petroleum systems of these relatively small syn-rift grabens in southern Hungary. We have developed a workflow for organic geochemical, seismic, and facies interpretation; basin subsidence; and 3D basin modeling to better understand the Miocene-Pliocene-age petroleum system in a [Formula: see text] study area. This area fully covers two small-scale (less than [Formula: see text] size each) troughs filled by syn-rift and postrift deposits in large thickness with significantly different structural histories. During our investigation, six source rock beds were identified and built into the model. Thousands of meters of Lower Miocene, (Karpatian age) sediment accumulated in a “pull-apart,” but later structurally inverted Kiskunhalas Trough in the south, where four moderate- to good-quality (2 wt% estimated original total organic carbon [TOC], 200 HI), dominantly gas-prone, immature to wet gas mature source rock beds were identified. In the overlying Middle Miocene (Badenian age) sediments, generally good quality (2 wt% estimated original [TOC], 300–500 HI, type II and II-S), oil-prone, dominantly oil mature source bed was identified. This layer, as the regional Miocene source rock, is mainly responsible for the known hydrocarbon (HC) accumulations. The 3D basin and petroleum system modeling helped us understand the HC migration into the already-discovered fields as well as identify possible future exploration objects.

The Complete Phylogeny of Pangolins: Scaling Up Resources for the Molecular Tracing of the Most Trafficked Mammals on Earth.

Pangolins, considered the most-trafficked mammals on Earth, are rapidly heading to extinction. Eight extant species of these African and Asian scale-bodied anteaters are commonly recognized, but their evolutionary relationships remain largely unexplored. Here, we present the most comprehensive phylogenetic assessment of pangolins, based on genetic variation of complete mitogenomes and 9 nuclear genes. We confirm deep divergence among Asian and African pangolins occurring not later than the Oligocene-Miocene boundary ca. 23 million years ago (Ma) (95% HPD = 18.7-27.2), limited fossil evidence suggesting dispersals from Europe. We recognize 3 genera including Manis (Asian pangolins), Smutsia (large African pangolins), and Phataginus (small African pangolins), which first diversified in the Middle-Upper Miocene (9.8-13.3 Ma) through a period of gradual cooling coinciding with a worldwide taxonomic diversification among mammals. Based on large mitogenomic distances among the 3 genera (18.3-22.8%) and numerous (18) morphological traits unique to Phataginus, we propose the subfamily Phatagininae subfam. nov. to designate small African pangolins. In contrast with the morphological-based literature, our results establish that the thick-tailed pangolin (Manis crassicaudata) is sister-species of the Sunda (Manis javanica) and Palawan (Manis culionensis) pangolins. Mitogenomic phylogenetic delineations supported additional pangolin species subdivisions (n = 13), including 6 African common pangolin (Phataginus tricuspis) lineages, but these patterns were not fully supported by our multi-locus approach. Finally, we identified more than 5000 informative mitogenomic sites and diagnostic variation from 5 nuclear genes among all species and lineages of pangolins, providing an important resource for further research and for effectively tracing the worldwide pangolin trade.

Late Neogene Radiolarian Biostratigraphy of the Eastern North Pacific ODP Sites 1020/1021

Abstract. During Ocean Drilling Program Leg 167, Sites 1020/1021 were drilled to assess the paleoceanographic conditions within the northern region of the California Current. Radiolarian records from the upper middle Miocene to Pleistocene were obtained at Sites 1020/1021 cores in order to develop a correlation between Neogene biostratigraphic data and paleomagnetic chronostratigraphy. Of 66 radiolarian events identified during this study, 26 Pleistocene to late Miocene events were directly tied to the paleomagnetic stratigraphy, and 40 middle to late Miocene events were correlated with that result by second-order methods based on the diatom biostratigraphy. The updated ages of radiolarian bioevents were estimated based on the geologic time scale of Ogg (2012). Of these events, 12 bioevents that define low-latitude tropical radiolarian zones were either missing at Sites 1020/1021, or proved to have different ranges from those in the tropics. Using selected bioevents of the temperate and subarctic species,...

Bioestratigrafia e inferências paleobatimétricas, com base em foraminíferos, do intervalo Paleógeno–Neógeno no norte da Bacia de Campos (poço Campos-01)

The micropaleontological analysis of a section of 1020 m (1760 m–2780 m) from the Campos-01 exploratory well, located at the Northern Campos Basin under 1338 m of water depth, provided a great diversity of foraminifera species recovered mostly from strata of Cenozoic age. The objective of this study is to recognize a biostratigraphic framework for the Paleogene–Neogene section crossed by the Campos-01 well, to identify unconformities in the sedimentary record, and to know paleoenvironmental characteristics of the interval in terms of paleobathymetry. For this study, 53 cutting samples were selected and the calcareous microfossils (planktic and benthic foraminifera) were analyzed both qualitatively and quantitatively. As a result of the observed stratigraphic distribution of planktic foraminifera species, the biozones P16 (uppermost Eocene), N4, N5?–N6?, N7, (lower Miocene), N8, N9, N10?–N13?, N14–N15 (middle–upper Miocene), N16 and N17 (upper Miocene), of Blow (1969), were recognized. The presence of two unconformities is suggested, representing biostratigraphical record breaks between the depth 2720 m and 2740 m (Paleocene–upper Eocene, middle part), and between the samples 2640 m and 2670 m (Oligocene). To the upper Eocene, the paleobathymetry was interpreted to have been outer neritic, which is supported by the reduction of the total abundance of foraminifera and the presence of a benthic foraminifera association typical of this environment. In the Miocene section, from the base to the top, it was noted that the percentage of planktic foraminifera corresponds to a trend of increasing paleodepth, indicating an increment of distance from the coast, with presence of genera and some species of benthic foraminifera that suggest the predominance of the upper bathyal paleobathymetry to this interval.