Six stages (OS1-6) were identified by Kellner (2015) to establish the ontogeny of a given pterosaur fossil. These were used to support the erection of several new Triassic taxa including Bergamodactylus wildi. which is based on a single specimen (MPUM 6009) from the Norian of Lombardy. Italy. https://www.mamapaisa.com/product-category/eye-protection-paper/