Palaeofloral and stratigraphic context of a new fossil forest from the Pliocene of NW Italy

In Pliocene sedimentary successions of northern and central Italy, fossil swamp forests are relatively common. Most of them pertain to the Piacenzian stage and show a dominance of the conifer Glyptostrobus europaeus as an arboreal element. A new fossil forest that recently cropped out at Fossano in the Piedmont region represents the first Zanclean assemblage of this type. Herein, we describe the context of the site and report the consistent stratigraphic and palaeofloral results so far obtained, also highlighting the need of more detailed future studies. Our results demonstrate that the fossil stumps exposed at Fossano pertain to two superposed forest beds, and the upper one is covered by a dense buried litter of Glyptostrobus europaeus shoots. Therefore, this conifer species is reconstructed as a dominant arboreal plant also in this fossil forest. Other interesting palaeontological information about the Pliocene succession of this relatively neglected area is provided by underlying and overlaying layers. Detailed macropalaeobotanical studies on leaves, fruits and seeds, provide good evidence for the palaeoecological and biochronological characterization of the succession. The integrated plant records (pollen and plant macrofossils) studied in a short interval of the succession correspond with the macrofossil records of the rest of the succession and point to the reconstruction of a “subtropical humid forest” grown under a very warm temperate climate regime, with a small range of temperatures and abundant and well-distributed rainfall throughout the year.