Taxonomy and palaeoecology of continental Gastropoda (Mollusca) from the Late Pleistocene mammoth-bearing site of Bullendorf in NE Austria

We present a taxonomic and palaeoecological analysis of a continental mollusc fauna from a mammoth-bearing succession near Bullendorf in Lower Austria. The taxonomic analysis comprises morphological descriptions and SEM documentation of 15 Pleistocene gastropod species. A Principal Component Analysis of the quantitative and qualitative composition of the investigated samples reveals a stratigraphic succession of four mollusc assemblages defined herein as Galba truncatula assemblage, Succinella oblonga assemblage, Pupilla muscorum/loessica and Pupilla alpicola/sterrii assemblages. The autecological requirements of the species of each assemblage allow a reconstruction of the palaeoenvironmental history of the section with alternating dry and humid conditions within a general cooling trend. Despite generally low mollusc density and species richness, the Bullendorf site allows important insight into latest Quaternary regional environmental conditions and climate. Based on the comparison with similar mollusc sites across Europe, a biostratigraphic correlation with the Late Pleistocene (~110\u201312 ka) is propose

New paleoenvironmental insights on the Miocene condensed phosphatic layer of Salento (southern Italy) unlocked by the coral-mollusc fossil archive

From the Late Oligocene to the Late Miocene, the central Mediterranean area was characterized by the extensive deposition of phosphate-rich sediments. They are usually represented by 10 to 20-cm-thick hardgrounds made of phosphatic and glauconitic sediments containing a rich macrofossil association. This study represents the first thorough investigation of the biotic assemblage of Mediterranean phosphorites aimed at collecting new information on the environmental factors controlling their deposition. The Serravallian/Tortonian phosphatic deposits of the Salento Peninsula (“Aturia level”) have been selected for the abundance of fossil remains and special attention is given to the coral–mollusc association. Two different facies have been recognized: a basal coral rudstone that includes most of the macrofossils, superimposed by a detrital rudstone made of thin layers mainly composed of phosphatic fragments. These two facies are separated by a phosphatic crust several millimeters in thickness. The coral assemblage contains at least 17 azooxanthellate taxa belonging to four families, while the molluscs are represented by a rich gastropod fauna (26 species), associated with bivalves (18 species) and cephalopods (two species). Four distinct depositional phases have been recognized, with the coral rudstone representing the key-facies to reconstruct the onset of the “Aturia level” and the original environment of its fossil content. The composition of the coral–mollusc association has been reliably compared with present-day analog taxa, suggesting the occurrence of a heterogeneous seafloor formed by rocky substrates and accumulations of soft sediment, at around 100–350-m water depth, and under the influence of moderate-to-strong bottom currents rich in nutrients and resuspended organic matter

Oligocene and early Miocene mammal biostratigraphy of the Valley of Lakes in Mongolia

The Taatsiin Gol Basin in Mongolia is a key area for understanding the evolution and dispersal of Central Asian mammal faunas during the Oligocene and early Miocene. After two decades of intense fieldwork, the area is extraordinarily well sampled and taxonomically well studied, yielding a large dataset of 19,042 specimens from 60 samples. The specimens represent 176 species-level and 99 genus-level taxa comprising 135 small mammal species and 47 large mammals. A detailed lithostratigraphy and new magnetostratigraphic and radiometric datings provide an excellent frame for these biotic data. Therefore, we test and evaluate the informal biozonation scheme that has been traditionally used for biostratigraphic correlations within the basin. Based on the analysis of the huge dataset, a formalised biostratigraphic scheme is proposed. It comprises the Cricetops dormitor Taxon Range Zone (Rupelian), subdivided into the Allosminthus khandae Taxon Range Subzone and the Huangomys frequens Abundance Subzone, the Amphechinus taatsiingolensis Abundance Zone (early Chattian), the Amphechinus major Taxon Range Zone (late Chattian), subdivided into the Yindirtemys deflexus Abundance Subzone and the Upper Amphechinus major T. R. Z., and the Tachyoryctoides kokonorensis Taxon Range Zone (Aquitanian). In statistical analyses, samples attributed to these biozones form distinct clusters, indicating that each biozone was also characterised by a distinct faunal type

Coastal landscape evolution in the Wilpattu National Park (NW Sri Lanka) linked to changes in sediment supply and rainfall across the Pleistocene–Holocene transition

Coastal sand dunes are sediment archives which can be used to reconstruct periods of aridity and humidity, past wind strength and variations in the sediment supply related to sea-level changes. In this manner, the sedimentary record of fossil coastal dunes in Sri Lanka provides evidence for environmental and climatic changes during the late Pleistocene and Holocene. As yet, these environmental shifts are poorly resolved because the sedimentary facies and their depositional architecture have not been studied and only very few age constraints are available. Facies analysis of a lithological section at the Point Kurdimalai sea cliff in the Wilpattu National Park (NW Sri Lanka) reveals a striking resemblance to the stratigraphic succession associated with the Teri Sands in southeastern India, which is better dated. The reason is that deposition occurred under the same geological, climatic and geomorphological conditions in the two regions. This special situation allows for litho- and climate stratigraphic correlations across the Gulf of Mannar and links the landscape evolution at Point Kudrimalai to late Quaternary climatic events and sea-level changes. Our results show that the formation of red coastal dunes (Red Beds) in Sri Lanka was a multi-phase process across the Pleistocene–Holocene boundary and hence the differentiation between an Older Group of Plio-Pleistocene age (including the Red Beds) and a Younger Group of Holocene age in the Quaternary stratigraphic chart for Sri Lanka is not justified

Oligocene–Miocene freshwater gastropods from the Oltu-Narman Basin in eastern Turkey

We describe the first record of a late Oligocene or early Miocene freshwater gastropod fauna from the Susuz Formation of the Oltu-Narman Basin in northeastern Anatolia. The assemblage consists of only six species, indicating the presence of a well-oxygenated lake, pond or anabranch rich in vegetation. Only two of the taxa are related to European Oligo-Miocene species. The fauna might be the first indication of a yet undocumented Eastern Anatolian freshwater biogeographic region, characterized by high endemism and minor influence from the coeval Peri-Paratethyan and Aegean–Anatolian regions in the west. The biostratigraphic value of the assemblage is low but might rather point to a Miocene age of the upper part of the Susuz Formation. Theodoxus susuzianus, Bithynia erzurumensis, and Valvata koehleri are described as new species

IN SEARCH OF THE EGGENBURGIAN – OTTNANGIAN BOUNDARY AT THE SOUTHEASTERN MARGIN OF THE BOHEMIAN MASSIF (LOWER AUSTRIA)

At the south-eastern margin of the Bohemian Massif in Lower Austria Eggenburgian to Ottnangian sediments are widespread. In the wider surroundings of Eggenburg nearshore clastic deposits of the upper Eggenburgian (Kühnring Mb., Burgschleinitz Fm., Gauderndorf Fm.) occur, which are discordantly overlain by shallow marine sublittoral bioclastic limestone of the Zogelsdorf Fm. Due to the ongoing transgression the Zogelsdorf Fm. shows a fining and deepening upward succession, passing upsection and laterally into marine clays and marls of the Zellerndorf Fm.Two completely cored logs from Limberg and Pulkau show this sedimentary succession above the crystalline basement. As in many outcrops, in the well Limberg KB2 on top of the Burgschleinitz Fm. a transgressional conglomerate occurs at the base of typical Zogelsdorf Fm. followed by pelites of the Zellerndorf Fm. The well Pulkau S1 exhibits between clastics of the Burgschleinitz Fm. and sands and limestone of the Zogelsdorf-Fm. a 4.5 m pelitic sequence with two tuffitic horizons. Between those notdateable tuffitic clays, badly sorted gravelly and sandy clay with molluscs like Granulolabium plicatum, Ostrea digitalina, Perna aquitanica, Cerastoderma edule, Taras rotundatus, Tellina planata, Cordiopsis incrassatus, Turritella sp., and Natica sp. indicates a deepening upward lagoonal environment. In dark gray fine bedded silty clays above thin shelled bivalves (Cardiidae, Veneridae, Lucinidea) and gastropods (Turritella eryna, Granulolabium plicatum) also point to shallow marine lagoonal conditions. This pelitic sequence is concordantly overlain by sands and sandy limestone of the Zogelsdorf Fm. and silty clay of the Zellerndorf Fm.Calcareous nannoplankton associations from the Burgschleinitz Fm. in Limberg KB2 can be correlated by Triquatrorhabdulus carinatus and Helicosphaera ampliaperta with the upper part of NN2. Sediments from the Zogelsdorf Fm. in the lower part of Limberg KB2 can be assigned to NN2/NN3 by H. ampliaperta and T. carinatus. Assemblages with H. ampliaperta and Reticulofenestra excavata in the lowermost part of the Zellerndorf Fm. in Pulkau S1 point to NN3.The successions in both wells show at the base upper Eggenburgian marine deposit (Burgschleinitz Fm.) followed by a regressional phase and a renewed transgression initiating the deposition in lagoonal facies in Pulkau S1. This regression presumably correlates with the main regional hiatus at the base of the Zogelsdorf Fm. and can be consequently correlated with the 3rd Order Sequence Stratigraphic Boundary Bur 3

Stratigraphic and paleogeographic significance of lacustrine mollusks from the Pliocene Viviparus beds in central Croatia

The mollusk fauna from the Pliocene Viviparus beds of Vukomeričke Gorice hills in central Croatia was investigated at four sites in the region of Kravarsko, S of Zagreb. The region represents a Pleistocene dome-anticline at the southern margin of the Sava depression. Sediments are dominated by clay, bearing some sand, gravel and lignite intercalations. The mollusks, comprising 11 gastropod and 2 bivalve species, prove the studied deposits to derive from the long-lived, highly endemic Lake Slavonia. The taxonomic revisions include the introductions of Viviparus kochanskyae n. sp. for specimens from Lake Slavonia previously identified with V. fuchsi NEUMAYR, 1872 and Prososthenia? praeslavonica n. nom. replacing the primary homonym Hydrobia vitrella BRUSINA, 1897 non Stefanescu, 1896. Recognized as an independent phase in the geodynamic evolution of the Pannonian Basin, the new regional stage Cernikian is introduced for the succession, defined by the complete depositional sequence of the Viviparus beds. Two stratigraphic horizons detected in the studied sites are constrained by the Lower Cernikian Viviparus kochanskyae and the Upper Cernikian Viviparus hoernesi zones and stay in perfect agreement with previous regional data. Timing of the Lake Slavonia history is enabled through several zonal markers calibrated to the Geological Time Scale in the Dacian Basin. Accordingly, the Lower Cernikian transgression dates to c. 4.3 Ma, the Upper Cernikian to c. 3.1 Ma, indicating strong alteration of the lacustrine depositional settings during the Pliocene, most likely related to changes in the regional climate. Interestingly, the second transgression of Lake Slavonia is marked by the evolution of strongly sculptured viviparid shells and coincides with the Pliocene Climate Optimum.</p