Palaeontology of the Upper Pliocene Marine Deposits of Rio Vaccaruzza, Villalvernia (Piedmont, Nw Italy)

Abstract

Abstract. The topmost Argille Azzurre (beds 1-2) and the basal Sabbie di Asti (beds 3-9) formations in the Villalvernia area are analysed in terms of palaeoecological and taxonomic features; the succession is 6 m thick and dates back to the middle Piacenzian within the Globorotalia bononiensis acme. The upper boundary of the clayey Bed 2 corresponds to an unconformity reflecting Pliocene tectonic activity. The study is focused on the fossil assemblages of beds 3, 4 and 9. The sandy Bed 3 yields 362 mollusc taxa; their assemblage is allochthonous and mixes infra- to circalittoral species accumulated by hyperpycnal mass-transport. The same mechanism is responsible for the origin of the overlying fossil unit (Bed 4) with numerous specimens of the Entobia-Gastrochaenolites ichnofacies. The autochthonous fossil assemblage of Bed 9 yields 308 molluscs, plus three brachiopods and ten fish taxa; most of them refer to the Posidonia meadow (HP), and their autochthony is shown by taphonomic features as skeletal integrity, mixing of successive generations or the limitation to juvenile ontogenetic stages of vagile and temporarily byssate species for which the HP performs a nursery function. Three brachiopods and 52 molluscs are here reported for the first time from the Pliocene of Piedmont. In the final chapter “Systematic Palaeontology” four brachiopods and 29 molluscs are described, among which there are eight new gastropod species: Crepidula bellardii n. sp., Conus dellabellai n. sp., Conus villalvernensis n. sp., Odetta chirlii n. sp., Ondina curta n. sp., Ondina elongata n. sp., Ondina pseudovitrea n. sp., Anisocycla subcylindrica n. sp.

Biogeographic history of Palearctic caudates revealed by a critical appraisal of their fossil record quality and spatio-temporal distribution

“…Remains attributed to extant species of Lissotriton (or to specifically indeterminate occurrences of this genus) are present in Eurasia from the Early Miocene to the Holocene, documented from localities in Austria, France, Germany, Greece, Hungary, Italy, the Netherlands, Poland, Romania, Russia, Slovakia, Spain and the UK [91,105,106,108,109,111–114,118,119,155–159,164–167,179,183,188–192] (figure 4 c ). Considering the high intra- and interspecific variation seen in extant Lissotriton , any specific attribution should be carefully reassessed [95,168,169].…”

Common and Rare Lower Pliocene Agglutinated Foraminifers of Piedmont (Northwestern Italy): Distribution, Taxonomy and Paleoenvironment

“…At the present state of study, the Pliocene marine deposits of the central Piedmont are limited to the Zaclean MPl4a foraminiferal subzone or to a not better determinable MPl4 zone. Younger marine deposits, dated to the Piacenzian MPl5a subzone, based on the occurrence of Globorotalia bononiensis Dondi, 1963 and/or Globorotalia aemiliana Colalongo & Sartoni, 1967, have been documented only out of the studied area, to the north on the western side of the Turin Hill (Tropeano et al 2014;Gattiglio et al 2015), along the northwestern side of the Monferrato at Casale Monferrato (Violanti & Sassone 2008), and to the east at Villalvernia (Pavia et al 2022).…”