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Middle Triassic calcareous algae and microproblematica from south China

The Yangtze carbonate platform (Southern China) recorded a long sedimentary evolution from Neoproterozoic to the basal Upper Triassic. During the Early and Middle Triassic, this platform was dominated by shallow-water carbonates. In various sectors of the platform, the Middle Triassic (Anisian-Ladinian) succession contain abundant assemblages of benthic foraminifera and calcareous algae. Following a previous paper about the Middle Triassic dasycladalean algae from SW Guizhou Province, the present study describes algae and microproblematic organisms from three sections: Honyan, Longtou and Guanling. Some dasycladalean algae are well known from the Alpine-Dinaric domain: Diplopora annulatissima, D. annulata, Euteutloporella triasina, Macroporella dinarica, Oligoporella minutula, O. pilosa pilosa, Poncetella hexaster and Pseudodiplopora proba. However, the dasycladalean association is dominated by species belonging to the genus Kantia, including K. cf. dolomitica and K. cf. comelicana. New Kantia species (K. intusannulata n. sp., K. granieri n. sp., K. muxinanii n. sp.) are characterized by the presence of intusannulation, a feature unknown from the Kantia species in the Alpine domain. The dasycladalean association also contains new species of the genus Mizzia and specimens belonging to the organo-genus Acicularia and/or Terquemella. Besides, rare specimens of "Solenopora" and Rivularia-type cyanobacteria are also present. The algal association is accompanied by microproblematic organisms including Tubiphytes sp., Zorniella obscura, Plexoramea cerebriformis, Ladinella porata, and Baccanella floriformis. Anisian-Ladinian foraminifera complete the micropaleontological spectrum of the sections studied. The most important are Meandrospira dinarica, Endotriadella wirzi, Paleolituonella meridionalis, and Turriglomina mesotriasica. The microfossils from the Middle Triassic Yangtze carbonate platform of south China belong to the Eastern Tethys province. Some of these species are also present in the Western Tethys (Alpine Domain). The new species presented in this study are absent from the Alpine Domain and probably represent endemic species for the Eastern Tethys.

Taxonomy and biogeography of living species of the Family Notorotaliidae (Notorotalia, Parrellina, Porosorotalia, Buccella, Cristatavultus)

DNA sequencing shows that species of the genera Notorotalia, Porosorotalia and Buccella form a distinct branch (Notorotaliidae) of Rotaloidea, and cluster as sister to Elphidiidae. In this review we report on the sequencing of three species of Buccella (from the Arctic Ocean, Patagonia and Chile) and one each of Notorotalia (New Zealand) and Porosorotalia (Chile). This information has been combined with all the morphological descriptive information on species of these genera plus the genera Cristatavultus and Parrellina to provide a global synthesis of living species of the Notorotaliidae. We recognize 11 species of the southern hemisphere genus Notorotalia, which has a centre of diversity around New Zealand (8 species). A second southern-hemisphere-restricted genus, restricted to eastern Australia is Parrellina (3 species) although specimens (possibly introduced) have been recorded from the Mediterranean Sea. Cristatavultus has a single species, with a tropical west Pacific distribution.We synonymize Cribrorotalia under Porosorotalia, which has a disjunct distribution with one species in the northwest Pacific and a second around the southern parts of South America. Buccella is the most diverse and widespread genus (16 species recognized) with its greatest abundance in the Arctic Ocean and around subantarctic-temperate South America. Five species of Buccella live in a belt along the west coast of central America, from USA to Peru, with some spillage into the Caribbean Sea and Gulf of Mexico. Two new species of Buccella are recognized: B. dejardini (from South Georgia) and Buccella n. sp. A (from Chile).

Open Access
Systematic paleontology and biostratigraphy of upper Eocene larger benthic foraminifera from Fanari (Thrace Basin, Greece)

Paleogene sedimentary deposits are exposed in several localities along the extended Thrace Basin in the Greek territory. One of the best sites in terms of preservation, richness and type of sediment occurs along the coastline of Fanari village (SW ofKomotini city). Two outcrops, which consist of upper Eocene shallowmarine clastic sediments, were sampled to analyze the full spectrum of larger benthic foraminifera (LBF) that comprises a rich and diverse assemblage of orthophragmines (Discocyclina, Orbitoclypeus and Asterocyclina), nummulitids (Nummulites, Assilina, Operculina, Heterostegina and Spiroclypeus), and other benthic taxa (e.g., Silvestriella, Pellatispira, Fabiania, Sphaerogypsina, etc.).Adetailed systematic description of LBF from Fanari is presented,which refines the biostratigraphic age of SBZ (Shallow Benthic Zone) 20 corresponding to the late Priabonian for the whole sequence. Twenty-four taxa among which six at (chrono)subspecies level belonging to twelve genera were identified and morphometrically analyzed for the first time from Greece. The LBF assemblage is characterized by the constant presence of Nummulites fabianii almost throughout the whole sequence. The most abundant species are Pellatispira madaraszi and Spiroclypeus carpaticus, though they occur in the upper part of the sequence along with orthophragmines. The foraminiferal distribution in the sequence enables paleoenvironmental observations and the reconstruction of the evolution of the Fanari area. Three main depositional marine shelf facies are distinguished at the shallow upper foreslope of the carbonate platform, making the Fanari section a key area not only of latest Priabonian but also of outer shelf biofacies.

Priabonian (upper Eocene) larger foraminifera from the Helvetic Nappes of the Alps (Western Switzerland): new markers for Shallow Benthic zones 19-20

Here, we revise and update the biostratigraphy of larger foraminiferal assemblages in three sections of the Priabonian Sanetsch Formation in the Helvetic Nappes of theWestern Swiss Alps: The SexRouge (SE) and the Sanetsch Buvette (SA) sections in the Wildhorn Nappe Complex, and the Col des Essets (ETS) section in the most external Morcles Nappe. In the SE and SA sections, the Tsanfleuron and most of the Pierredar Limestone members of the formation are assigned to SBZ 19 (early Priabonian), while the uppermost part of the formation is assigned to SBZ 20 (late Priabonian). In the external ETS section the entire Sanetsch Formation contains assemblages characteristic of SBZ 19, suggesting an earlier, middle-late Priabonian onset of the hemipelagic Stad Formation (Globigerina MarlsĀ). Since it was established in 1998, the Shallow Benthic Zones (SBZ), a biozonation based on larger foraminifera, has been a useful tool in the biostratigraphy of the Paleogene. Biozonation proposals for the late middle-late Eocene are based mainly in biometrical subdivision of lineages of nummulitids and orthophragmines,which requiresmeasurements in oriented sections of isolated specimens. Here, we define previously unreported taxa from the Sanetsch Formation, which are considered characteristic for the Priabonian. They are easy to identify in random sections and thus useful biostratigraphical markers.We also describe a new orthophragminid genus, Virgasterocylina n. gen. (Orbitoclypeidae) characterized by the presence of rods, radial thickenings of calcite along ribs; a new species of Rotorbinella, R. epardi n. sp., and a new genus and new species of difficult suprageneric attribution, Sanetschella indeprensa n. gen., n. sp. We add the new taxa to the larger foraminiferal association characterizing the Priabonian (SBZ 19-20). The revision of the literature, together with our own sample collections revealed that these new taxa occur in Priabonian rocks from different basins in the western Tethys. Virgasterocylina n. gen. also occurs in the Caribbean bioprovince in the middle and upper Eocene. In the western Tethys, Virgasterocylina ferrandezi is subdivided into two subspecies, V. f. ferrandezi (Ozcan and Less) and V. f. lessi n. ssp., which characterize the SBZ 19 and 20 biozones respectively.