The dual provenance of the Osteno fossils.
As has been written in numerous publications, Osteno fossils come from a quarry (Dulio quarry or "Dui") located west of the location known as the Free Port.
The discovery of the deposit adjacent to Porto Franco took place quite randomly and fortuitously. In 1964, Mr. Pio Mariani, a well-known mineral collector and trader from Desio (Milan) was in the vicinity of Albogasio. He noticed that in the pillars of a gate were cemented two perfectly preserved splendid crustacean fossils. Mr. Pio Mariani discovered that the gate was owned by the owner of the S. Margherita quarry near Porto Franco (Osteno), who supplied the collector with some specimens. In 1965 Pio Mariani reported the discovery to the well-known paleontologist John Pinna giving him the specimens purchased from the quarry owner. Pinna went to the site in the same year, when the quarries were still in operation, recovering extremely interesting new material. Later, in the summer of 1966, the quarries were closed because they were considered unsafe, this made it difficult to find new materials. The discovery was followed by numerous studies by the Milan Museum of Natural History associated with new paleontological excavations that led to several interesting discoveries.
The scholars themselves recalled this important association, we recall some words of Giovanni Pinna: "in September 1968, having gone to Osteno again, I managed to obtain from the owner of the quarry Mr. Steffenini, whom I thank very much here, two new specimens in excellent condition, almost complete, lying on the rock...."
The collection of new fossil specimens has not only involved the Porto Franco quarry; another site that has provided very similar remains is the Quaglietto Quarry, placed upstream of the village of Osteno (Claino con Osteno). The quarry, owned by Mr. Emilio Vitali, was operational until 1980, then closed following a terrible misfortune: a slab slipped and two workers were crushed to death! The event meant the permanent closure of a business that had lasted for generations.
Even this second excavation, prior to the tragic 1980, unearthed several fossil remains that were given to paleontologists studying Osteno's fauna; the cessation of activity prevented further material from being recovered.
Quarrying in the Osteno quarries was a family affair; generally, the material collected was exported for construction sites located in different areas of the Lario and Ceresio. As Cereghini recalls in an interview with Mr. Vitali: "the activity involved stories of toil, of long days spent preparing the mine holes, then the explosive blasts, and, then, endless hours spent splitting the slabs with wedges and sledgehammers to make lighter, more manageable pieces. Then the stones on the wagons would directly reach the construction sites or transport barges on the shore. Only later did the use of motorized vehicles save some effort and deliveries became more punctual and longer range.".
The Osteno fossil collection actually comes from two quarry sites: the Porto Franco quarry and the Claino con Osteno quarry.This article was meant to remind us of the good partnership created between the scholars of the Milan Museum and the quarry owners. It is possible that in the initial stages there was some reticence, but the follow-up showed full cooperation and the "end (often) justifies the means!"
