Konopiská pri Rohožníku is one of the major Slovak paleontological sites, that includes finds of fossilised marine fauna from the Tertiary Period.  The site, a former clay extraction pit and the close by surrounding area, is situated east of the municipality of Rohožník which can be found on the eastern edge of the Záhorská nížina lowland.  Various types of marine clay, sand, arenaceous clay and algal marls that contained a wide range of fossilised marine fauna (invertebrates and vertebrates) were discovered in the clay pit.  These animals come from the younger Tertiary Period – the Miocene, when, approximately 13 million years ago, sedimentation took place in the shallow and deep marine environments on the eastern edge of the Vienna Basin, which at that time was one of the bays of the Central Paratethys.  

     Included within the clay sediments was a specific population of gastropods among which common, rare and previously undescribed species were identified. One of the newly described species of molluscs from the site was a predatory thermophilic marine gastropod from the family Costellariidae – Vexillum svagrovskyi. The species was named in honour of prof. Jozef Švagrovský (1921–1985), an outstanding Slovak geologist, palaeontologist and university teacher.  A similar species, Vexillum neudorfensis, was discovered in the borough of Devínska Nová Ves. It differs from the former with transverse ribs and spiral grooves that are evenly developed on all whorls, plus five columellar folds. 

     Approximately 13 million years ago, populations of Vexillum svagrovskyi lived in marine paleo-environments of the deep sub-littoral zones with a soft muddy seabed. The species had adapted to the unfavourable environmental conditions that were characterised by a reduced flow of water and a low oxygen concentration near the seabed. The postage stamp depicts a holotype that is deposited, together with other exemplars, in the collection of the Museum of Natural History of the Slovak National Museum in Bratislava.  

     Vexillum svagrovskyi is a precious endemic species that has only been found in the paleontological site at Konopiská pri Rohožníku. Its discovery supplements and updates our knowledge of the diversity of fossil molluscs that lived in the Neogene Sea of Paratethys.   

Radoslav Biskupič