Three-dimensional seismic investigations of the Sevastopol mud volcano in correlation to gas/fluid migration pathways and indications for gas hydrate occurrences in the Sorokin Trough (Black Sea)

New 3-D seismic investigations carried out across the Sevastopol mud volcano in the Sorokin Trough present 3-D seismic data of a mud volcano in the Black Sea for the first time. The studies allow us to image the complex three-dimensional morphology of a collapse structured mud volcano and to propose an evolution model. The Sevastopol mud volcano is located above a buried diapiric structure with two ridges and controlled by fluid migration along a deep fault system, which developed during the growth of the diapirs in a compressional tectonic system. Overpressured fluids initiated an explosive eruption generating the collapse depression of the Sevastopol mud volcano. Several cones were formed within the depression by subsequent quiet mud extrusions. Although gas hydrates have been recovered at various mud volcanoes in the Sorokin Trough, no gas hydrates were sampled at the Sevastopol mud volcano. A BSR (bottom-simulating reflector) is missing in the seismic data; however, high-amplitude reflections (bright spots) observed above the diapiric ridge near the mud volcano at a relatively constant depth correspond to the approximate depth of the base of the gas hydrate stability zone (BGHSZ). Thus we suggest that gas hydrates are present locally where gas/fluid flow occurs related to mud volcanism, i.e., above the diapir and close to the feeder channel of the mud volcano. Depth variations of the bright spots of up to 200 ms TWT might be caused by temperature variations produced by variable fluid flow

Megascyliorhinus miocaenicus (Chondrichthyes, Galeomorphii) from the Zanclean (early Pliocene) of San Quirico d'Orcia, central Italy

Two almost complete teeth, one anterior and one lateral, of the extinct shark Megascyliorhinus miocaenicus (Antunes & Jonet, 1970) are reported from the early Pliocene of San Quirico d'Orcia, Tuscany, central Italy. The teeth are similar in size and morphology (vertical striations of the crown base, indistinct cutting edge of the crown and accessory cusplets) to conspecific teeth described in literature. This is the first unequivocal report of a rare and enigmatic shark in the Pliocene of central Italy. A Pliocene tooth from Allerona, Umbria, central Italy, formerly assigned to Scyliorhinus sp., may also belong to Megascyliorhinus miocaenicus

A large clavatulid species first reported from the Early Pliocene of Italy (Gastropoda, Neogastropoda, Conoidea)

Shells of a species of Perrona, a genus never reported before from the Pliocene of Italy, were collected in the Early Pliocene of southern Tuscany over the last twenty years. These shells recall those of P. villarrasensis Vera-Peláez & Lozano-Francisco 2001, from the Early Pliocene of southern Spain, by virtue of shape, size and development of parietal callus. However the poor condition of available material and the lack of a reliable taxonomic framework for this group of Euro-Mediterranean fossil clavatulids make it difficult to propose a realistic determination. The finding of a species of Perrona in the Pliocene of Italy is very interesting. During the Miocene species of Perrona were common and widespread in the Euro-Mediterranean area, but in the Early Pliocene only four species survived in southern Spain and records from the eastern Mediterranean are limited to one from Tunisia and the present from southern Tuscany

The lost Aporrhais species from the Italian Pliocene: A. peralata (Sacco, 1893) (Gastropoda, Caenogastropoda)

Three Early - Middle Italian Pliocene aporrhaid species are redescribed on the basis of material from the Siena and Radicofani basins (central Italy). Two of them, Aporrhais pespelecani (Linnaeus, 1758) and Aporrhais uttingeriana (Risso, 1826), are well known but the third, Aporrhais peralata (Sacco, 1893), has been almost completely overlooked despite its probable widespread distribution in the Italian Pliocene. This species, characterized by peristome with large parietal callus, long adapical digitation, thick laminar abaxial lip with three short digitations and short abapical digitation, is distinct from other Euromediterranean Pliocene to Recent species. However problems remain with specimens of Aporrhais serresiana (Michaud, 1828) having a wider lip and shorter digitations. The latter were formerly assigned to a different species, Aporrhais macandreae Jeffreys, 1867, but are now considered conspecific with A. serresiana, though re-analysis of their taxonomic status by modern approaches would be useful. A. peralata is distinct from these specimens by virtue of its more delicate axial sculpture, more obtuse spire and larger abaxial lip with shorter digitations

Biagio Bartalini's "Catalogo dei corpi marini fossili che si trovano intorno a Siena" (1776).

In 1776, the Sienese botanist Biagio Bartalini (1750–1822) published a catalogue of wild plants growing around Siena, adding an appendix on fossils found in the same area, that is the first monograph on Sienese fossils and one of the first works of its kind in Italy. This paper provides tentative identifications of the species and an analysis of the value and meaning of Bartalini's work. The catalogue reports 72 species, each denoted by a list of names applied to analogous living taxa. Identification of single entities is extremely problematical because it can only be attempted through analysis of the literature, since the original material cannot be traced. The most interesting report is the first record of a Euro-Mediterranean Pliocene species of Sthenorytis (Gastropoda, Epitoniidae). Though important, the catalogue is incomplete, with oversights and mistakes, suggesting little familiarity with the subject. Shortcomings include some inconsistencies in the species sequence, the report of giant clams and the absence of molluscs ubiquitous in the Sienese Pliocene and sharks. Nor is it true that it is the first Italian palaeontological work in which binomial nomenclature was used, as sometimes claimed. </jats:p