Anatoma, Woodward, 1859

Hansen, Thomas, 2019, Gastropods from the Cretaceous-Palaeogene boundary in Denmark, Zootaxa 4654 (1), pp. 1-196 : 62-64

Anatoma ? sp. B

Fig. 20J

Material. Specimen MGUH 33092, representing a very fragmentary external mould. Occurrence. Lithified top of the Maastrichtian Højerup Member, Tor Formation, at Rødvig, Stevns Klint.

Description. Adapical part of spire whorl weakly convex, nearly horizontal. Base moderately convex. Sculpture on spire whorls consisting of close to 60 sigmoid transverse threads per whorl, threads continuing onto base, becoming slightly opisthocyrt to sigmoid. Transverse threads crossed by weaker, more closely spaced spiral threads.

Remarks. The fragmentary state of the specimens makes generic classification rather difficult, but it is here tentatively assigned to Anatoma . Anatoma ? sp. B resembles the contemporaneous Anatoma sp. A described above, but differs by the weakly sigmoid transverse threads and the closely spaced spiral threads.

Figures

FIGURE 20. A–B. Palaeoloxotoma sp., inner mould of MGUH 33087. Length 17.2 mm. C–I. Anatoma sp. A. C–E. Silicone casts of MGUH 33088. Width 1.3 mm. F–G. Silicone cast of MGUH 33089. Width 1.9 mm. H. Silicone cast of MGUH 33090. Preserved width 1.35 mm. I. Silicone cast of MGUH 33091. Preserved width 1.35 mm. J. Anatoma? sp. B, Silicone cast of MGUH 33092. Preserved width 1.05 mm. K–M. Temnotropis stevniensis n. sp. K–L. Silicone cast of holotype MGUH 33093. Width 3.5 mm. M. Umbilical view of paratype MGUH 33094. Width 2.1 mm. N–P. Leptomaria niloticiformis Schlotheim, 1820. N–O. Inner mould of MGUH 33095. Width 44 mm. P. Silicone cast of MGUH 33096. Middle Danian Coral Limestone from Faxe, Denmark. Height nearly 11 cm. Q. Leptomaria meyeri Pacaud, 2004. Silicone cast of MGUH 33097. Cast 14.5 mm wide, 12.5 mm high.