Gli ammonoidi della Formazione di Besano pubblicati da Airaghi nel 1912 conservati al Museo Kosmos di Pavia

Abstract

Ammonoids from the Besano Formation published by Airaghi in 1912 kept at the Museo Kosmos in Pavia. The ammonoids from the Besano Formation described by Airaghi in two works in 1912, belonging to the collections of the Museo di Storia Naturale di Milano, as well as many other historical collections stored in this museum, have been lost during World War II. However, some plaster casts of these specimens were recently found among the material stored in the new Museo Kosmos in Pavia during a reorganization of the deposits. The plaster casts, probably made by Airaghi, were obtained from the original specimens corresponding to some species erected by Airaghi and coming from the mine of Tre Fontane (Mt. San Giorgio, Switzerland). Lacking original specimens and related stratigraphic data, the present material is herein reclassified and considered as complementary for the corresponding neotypes, previously stated by Rieber in 1973. Among the taxa not revised in literature, two new combinations are here proposed: Serpianites marianii (Airaghi 1912) and ?Nevadites bassanii (Airaghi 1912). With these plaster casts we also uncovered some original specimens never described. The majority of the material is paired with the original labels by Airaghi. These ammonoids are characteristic of the lower and upper Secedensis Zone (Upper Anisian, Middle Triassic) of the Besano Formation. It is very likely the herein described specimens were collected in the beds belonging to the Secedensis Zone of the mine Tre Fontane which have been completely removed in the first years of excavation activity. [Article in Italian]