The Norian Worthenia-like gastropods (Main Dolomite, Upper Triassic): reclassification of the specimens housed at the “Antonio Stoppani” Natural Museum, Italy

Despite being very common, the Norian gastropods of the Main Dolomite Formation usually referred to as “Worthenia”, have not been well classified yet. This is principally due to a dearth of well-preserved specimens. Moreover, the type material of the species instituted by Stoppani has not been re-examined in recent publications. Therefore, a thorough search for the Stoppani Collection’s reference types in the storerooms of the Museo di Storia Naturale di Milano has been carried out. This investigation revealed that the gastropod types from Main Dolomite described by Stoppani had effectively been lost, possibly following an air-bombing raid hitting the museum during World War II. Consequently, we here describe only two specimens from the portion of the Stoppani Collection housed at the Museo Scientifico Naturalistico “A. Stoppani”, Venegono Inferiore (Varese, Italy). These two specimens were collected by Antonio Stoppani in Songavazzo (Bergamo, Italy) that he himself identified as one of the type localities. These particularly well-preserved specimens display characters useful for their possible attribution to the genus Wortheniella.