查看更多>>摘要：Fish otoliths have been obtained from the early Miocene (Aquitanian) Pentalofos Formation of the Mesohellenic Basin in northern Greece. These specimens represent the earliest Miocene shallow marine otolith records from the Mediterranean. Here, we describe the goby otoliths of the assemblage, which are the most common group at this location. They represent the earliest recognized species of two of the three main extant Atlantic-Mediterranean goby groups, the Pomatoschistus lineage and the Aphia lineage. The taxa are interpreted as being phylogenetically positioned near the base of their respective lineages. The new taxa described are Hellenigobius praeschismatus n. gen. et n. sp. and Plesiogobius felliensis n. gen. et n. sp. A third species is tentatively related to Nematogobius in open nomenclature.
Crespo, Vicente D.Gamonal, ArturoMontoya, PliniRuiz-Sanchez, Francisco J....
18页
查看更多>>摘要：Two species of the family Eomyidae are identified in the early Miocene localities of the Araia d'Alcora outcrop (Ribesalbes-Alcora Basin, Iberian Peninsula): Ligerimys florancei and Ligerimys ellipticus. The first is rarer than the second, which is one of the most abundant mammals in the Ribesalbes-Alcora Basin assemblages. Due to its abundance, we are able to describe its variability in dental morphology, showing characteristics never previously observed, including the presence of a mesoloph or other features previously described only in ancient assemblages of this species, such as the presence of the anteroloph, which appears in younger assemblages in the Araia sequence. Furthermore, based on the eomyids, we divide the record of the Campisano Ravine section into two long local biozones, depending on the species present. In addition, each local biozone is divided into two smaller subbiozones, depending on the abundance of each species. We retrospectively compare and correlate the assemblages studied here with other Ligerimys assemblages from the other basins in the Iberian Peninsula. We classify these sites based on the abundance and species of the genus Ligerimys. Additionally, we discuss the palaeoecological preferences of these species.
Bosellini, Francesca R.Vescogni, AlessandroBudd, Ann F.Papazzoni, Cesare A....
24页
查看更多>>摘要：The Oligocene, well known as the apex of Cenozoic reef growth, is a crucial period of time to investigate the mutual relationship between coral reef construction and coral diversity and their link with palaeoclimate and palaeoenvironmental changes. Here we provide a complete characterization of the Upper Oligocene reef complex of the Castro Limestone (Salento Peninsula, S Italy), which is one of the best-preserved Oligocene coral reefs of the Mediterranean region. By combining facies analysis with the first detailed characterization of its coral fauna, we show that the Castro Limestone has both a rich scleractinian coral fauna (25 genera and 41 species) and a large reef volume, and it represents a luxuriant fringing reef formed within the euphotic zone in clear water conditions facing the open sea. The coral fauna differs both in its composition and in its proportions among reef palaeoenvironments, ranging from the shallow back reef to the fore reef slope, and its stratigraphic and palaeogeographic distribution testifies to the persistence of a cosmopolitan Tethyan fauna in Oligocene time, with the Mediterranean and Indo-Pacific provinces being more closely connected than the Mediterranean and the Caribbean. The age of the Castro Limestone is here reassigned to the middle-late Chattian, which coincides with the Late Oligocene Warming Event (LOWE) when atmospheric CO2 values declined. We suggest that the strong reef-building capacity of the Castro Limestone, coupled with high coral diversity, was not hampered by warming conditions but most probably promoted by the reduced pCO(2) and a suitable local/regional physiographic setting.
查看更多>>摘要：Calcareous nannofossil biostratigraphy was conducted across the Toarcian Oceanic Anoxic Event (TOAE) interval cored at Colle di Sogno and Gajum in the Lombardy Basin (Southern Alps, Northern Italy). Drilling at both sites resulted in 100% recovery of unweathered material. The Sogno and Gajum Cores consist of pelagic marly limestones, marlstone, marly claystone, and a relatively expanded black shale interval named Fish Level considered the lithostratigraphic record of the T-OAE at regional scale. Semiquantitative analyses of calcareous nannofloras allowed to achieve a high-resolution biostratigraphy of the latest Pliensbachian-early Toarcian time interval. Several nannofossil biohorizons were detected, including zonal/subzonal markers and additional events related to changes in abundance. The nannofossil biostratigraphic correlation of the Sogno and Gajum Cores indicates that, according to their paleogeographic settings, the succession recovered in the Sogno Core deposited on a pelagic plateau is continuous while a hiatus of similar to 600 kyrs was detected in the lower-most Toarcian in the Gajum Core located on a slope of a structural high. The NJT 5 and NJT 6 Zones of the standard nannofossil zonation for the Mediterranean Province were identified in both the Sogno and Gajum Cores. Our findings allow an implementation of the reference biozonation with the separation of the NJT 6a and NJT 6b Subzones, and age revision of some secondary events. The zonation established for the Lusitanian Basin (Portugal) is only partially reproducible in the Lombardy Basin, confirming nannoplankton paleoprovincialism during the Early Jurassic requiring different zonal schemes in various areas. Nevertheless, we underline that the T-OAE is unambiguously constrained by the FO of C. superbus crassus and the LO of M. jansae at supra-regional scale.
查看更多>>摘要：The middle Jurassic successions that are currently exposed in eastern spain (southeastern iberian Range) were deposited in a system of shallow carbonate platforms, constituting the western margin of the Alpine Ocean, and display a series of successively interbedded volcaniclastic rocks and minor lava flows. The large-scale mapping reveals that middle Jurassic volcanic rocks crop out along NW-sE pathways, highlighting the importance of the role played by tectonics in controlling the spatial distribution of volcanic outcrops. The progressive dismemberment of Pangea impelled a geographic provinciality increase and, thus, might have contributed to a growing speciation rate of marine invertebrate organisms, notably ammonites. The present study provides new data constraining in detail the age of the middle Jurassic volcanic deposits. The biochronostratigraphic calibrations of the sedimentary host rocks encasing the volcanics have been obtained from the study of the fossil content (mainly ammonites) from16 well-exposed stratigraphic sections. The study of the fossils from these sections has enabled the identification of three volcanic episodes during the murchisonae Zone (Aalenian), the Concavum-Discites zonal boundary (Aalenian-Bajocian), and the late laeviuscula Zone or laeviuscula-Propinquans zonal boundary (Bajocian). Precise age constraints for volcanic accumulations can be a significant contribution in reconstructing the geodynamic history of the Iberian Basin.
查看更多>>摘要：The family Bathylagidae (deep-sea smelts) is a group of marine meso- and bathypelagic argentiniform fish with relatively poor fossil record. The described specimens from the Egerian deposits of the Krumvir locality, named Krumvirichthys brzobohatyi gen. et sp. nov. represent oldest verifiable record of the bathylagid fishes known up to date. The new genus and species is characterized by semicircular orbitosphenoid at the dorsal section of the orbit, basisphenoid developed, opercle bearing posterodorsally developed large process, opercle and subopercle posteroventrally radially grooved, preopercle with triangle-shaped process at the posteroventral margin of the bone, cleithrum with enlarged triangle-shaped posterior lamina, no postcleithra, pectoral fin with eight or nine rays and elongated up to the level of the insertion of the dorsal fin, pelvic fin with nine rays inserted just below the middle of the dorsal fin, dorsal fin with ten or eleven rays, up to eight supraneurals presented in front of dorsal fin, vertebral column consists by at least 23 + 21 vertebrae, body covered by thin and large cycloid scales, and lateral line scales reinforced around tubular part. The combined presence of the orbitosphenoid and basisphenoid in new species particularly reminds the Recent bathylagid genera Lipolagus, Melanolagus, and Bathylagichthys.
查看更多>>摘要：In the second issue of Samuel Morton's "Synopsis of the Organic Remains of the Cretaceous Group of the United States" published in June 1835, several otodontid shark teeth from Cenozoic formations of New Jersey are named with authorship of Louis Agassiz and meet the conditions of availability of the International Code of Zoological Nomenclatural. It has gone largely unnoticed that some of these names were introduced in this work before their publication in Agassiz's masterpiece "Recherches sur les poissons fossiles". The specimens presented by Morton were kept in the John Price Wetherill (1794-1853) collection that found its way into the paleontological collection of the Academy of Natural Sciences of Drexel University, Philadelphia, where most of them have been rediscovered. These teeth are part of the type series upon which Agassiz introduced Lamna obliqua Agassiz in Morton, 1835, Lamna lanceolata Agassiz in Morton, 1835, Carcharias lanceolatus Agassiz in Morton, 1835, Carcharias megalotis Agassiz, 1835 and Carcharias polygurus Agassiz in Morton, 1835, all of these species being referred to the genus Otodus in the present work. In order to secure the nomenclatural stability of the Otodontidae, it is established that Otodus lanceolatus is a junior synonym of Otodus obliquus, that "Carcharias" lanceolatus belongs to the genus Otodus Agassiz, 1838 and is invalid as a junior secondary homonym of Otodus lanceolatus, that Otodus megalotis is a junior synonym of Otodus auriculatus (Blainville, 1818), and that Otodus polygurus (Otodus polygyrus being an incorrect subsequent spelling) is a junior synonym of Otodus megalodon (Agassiz, 1835). Furthermore, it is shown that the date of publication of Otodus obliquus (Agassiz in Morton, 1835) is 1835 and not 1838 as previously thought.
查看更多>>摘要：The depocenters of epicontinental basins usually comprise relatively continuous depositional records, and these can be used in the determination of sediment routing and paleogeographic changes via a set of various geophysical, sedimentological, biostratigraphic and geochronological approaches. although the margins of such basins will have a major role as constraints for that sediment routing, their depositional records are typically scarce and incomplete, posing a common challenge in terms of gaining information about them. the present study focuses on the upper Miocene succession present in the Male Karpaty Mts., a pre-cenozoic horst dividing the vienna and Danube basins (central Europe). The data gained by facies analysis, biostratigraphy, shallow seismic survey, authigenic Be-10/Be-9 dating and correlation of archival borehole profiles reveals, that the succession under consideration represents a record of the lake Pannon transgression, which appeared in the study area at similar to 10.9-10.6 ma. The subaerially exposed granitic massif and middle miocene successions sourced a shoal water delta, which intercalated with wave-induced dunes and open lacustrine muds in brackish sublittoral to marginal littoral environments. the granitic massif was probably also exposed later, during the regression of lake Pannon at similar to 10.2-10.0 ma, as a result of the progradation of the paleo-Danube delta from the vienna Basin southeastwards. The depositional record of the regressive sequence was documented and dated in well-cores from the nearby Danube Basin margin. The documented scenario of transgression preceding the overall regression of the paleo-danube delta system by a relatively short period is characteristic of several other localities across the Pannonian Basin system, and may imply that the progradation of depositional system caused a base-level rise on account of sediment loading-induced subsidence.
查看更多>>摘要：Palynological assemblages from cores 11 to 14 of Makhtesh Qatan-2, core 3 of Ramon-1 and core 3 of Boqer-1 boreholes from the Arqov Formation of the subsurface of the Negev, southern Israel, suggest that at least part of the Arqov Formation can be characterised by Cedripites priscus, Reduviasporonites chalastus and particularly Pretricolpipollenites bharadwajii, while the Saad Formation contains a slightly less diverse assemblage lacking the three taxa above. Palynological evidence is broadly consistent with other palaeontological evidence suggesting that the Saad Formation is in part likely to be Wuchiapingian in age, and the Arqov Formation is at least in part Changhsingian. These conclusions are tentative because core data is restricted to very few well penetrations and a total lack of surface exposure of the Permian.
NSTL
Univ Studi Milano