Gastropods from the Cretaceous-Palaeogene boundary in Denmark Author Hansen, Thomas text Zootaxa 2019 2019-08-12 4654 1 1 196 journal article 26049 10.11646/zootaxa.4654.1.1 9ce1d103-9234-4fbe-9544-f1c294bb8783 1175-5326 3365803 CFD82CC0-3110-472E-972B-7ADC0C523A04 Vatopsis heinbergi n. sp. Figs 28 T–V Diagnosis. Fairly broad-spired with strongly flattened whorls; periphery located close to abapical suture; transition to base sharp. Protoconch with a single spiral thread. Derivation of name. In honour of C. Heinberg, who found the holotype and has dedicated much of his scientific effort into the study of the fauna and environments at the Danish Cretaceous-Palaeogene boundary. Type material. The holotype MGUH 33220 is a nearly complete external mould with protoconch. Paratypes MGUH 33221 and MGUH 33222 are from the Cerithium Limestone Member at Skeldervig, Stevns Klint. Type stratum and type locality. The lower Danian Cerithium Limestone Member at Hulerne (The Caves) near Storedal at Stevns Klint . Occurrence. The lower Danian Cerithium Limestone at Stevns Klint. Description. Protoconch planktotrophic turriculate, 0.85 mm high and 0.5 mm wide, consisting of around 5 ½ moderately convex whorls. Embryonic whorl slightly inflated, smooth. Second whorl too worn for a clear view of any potential sculpture. Succeeding whorls carrying 13–14 slightly opisthocline and opisthocyrt collabral threads per half whorl. The collabral threads may just cross single spiral thread appearing at periphery near abapical suture on final two whorls. Teleoconch with flattened whorls with sharp transition to flat base. Aperture only partly preserved, appearing to have a straight columella. Teleoconch sculpture reticulate with around 16 opisthocline transverse ribs per whorl on first teleoconch whorl. Transverse ribs crossed by three or four spiral ribs, the strongest located on keel slightly above abapical suture and succeeded by weaker abapical rib. Connecting points marked by tubercles. Base with strong spiral rib close to abaxial margin; otherwise smooth. Measurements. The holotype MGUH 33220 is 3.3 mm high and 1.2 mm wide, consisting of five teleoconch whorls in addition to protoconch. Remarks. The taxon appears to resemble the Bohemian Cerithium ternatum Reuss, 1845 , but differs at least by the better developed spiral and transverse ribs in contrast to the tubercle sculpture.