Arthrodendron borberensis sp. nov. is described from the Pagliaro Formation (Paleocene) of the Northern Apennines. Specimens of the new species are preserved on the sole of a turbiditic sandstone bed. Arthrodendron borberensis sp. nov. is characterized by its long chambers (some exceeding 10 mm in length), its generally straight course, and rare branching at an acute angle. This large foraminifer lived infaunally within the sediment and possibly as epifauna after exhumation by erosion, prior to the deposition of the host turbiditic sandstone bed. Assemblages of smaller agglutinated foraminifera (a flysch-type fauna) and trace fossils (Nereites ichnofacies) point to a deep-sea environment for the discussed protist.