Galericulus, Seeley, 1861

Hansen, Thomas, 2019, Gastropods from the Cretaceous-Palaeogene boundary in Denmark, Zootaxa 4654 (1), pp. 1-196 : 92

Galericulus sp.

Figs 24 S–W

Material. Three nearly complete internal moulds ( MGUH 33152, MGUH 33153 and ØSM.10042-311) with parts of external mould preserved.

Occurrence. Lithified top of the Maastrichtian Højerup Member north of Kulsti Rende and the middle part of the lower Danian Cerithium Limestone Member near Knøsen, Stevns Klint. Specimen MGUH 33152 is indicated to have come from the lithified top of the upper Maastrichtian Højerup Member, but the matrix would rather suggest the lower Danian Korsnaeb Member, probably from one of the Danian Thalassinoides burrows into the Cretaceous strata.

Description. Shell thin, cap-shaped with protoconch located close to posterior margin. Highest point of shell situated 2/3 of shell length from anterior margin or farther back. Interior with thin process or plate reaching from just behind apex and halfway to highest point of shell or, in specimen MGUH 33152, to around midline of shell. A possible muscle scar describes a wide semicircle halfway between apex and anterior margin. Outer surface characterized by irregular growth increments and very fine and dense radial striae and coarser, short radial ribs unevenly distributed across the surface.

Measurements. Specimen MGUH 33152 is 8.0 mm long, 8.5 mm wide and nearly 4.0 mm high.

Remarks. The Danish specimen strongly resembles the British Albian type species of this genus, but may differ by a more horizontally directed inner process and a less steep anterior margin. These characters may on the other hand just as well reflect environmental influences on the growth. The age difference may be the strongest support for regarding this as a separate species.

Figures

FIGURE 24. A. Tenagodus sp., Silicone cast of MGUH 33139. Tube diameter 5.6 mm. B–D. Campanile selandicum (Lundgren, 1867). B–C. Silicone cast of MGUH 33140. Width 11.4 mm. D. Silicone cast of MGUH 33141. Width 4.5 mm. E–F. Campanile sp. A. Silicone cast of MGUH 33142. Whorl height 2.1 mm. G. Campanile sp. B. Silicone cast of MGUH 33143. Height 4.2 mm. H–K. Metacerithium balticum (Ravn, 1902). H. Silicone cast of protoconch MGUH 33144. Width 0.45 mm. I. Silicone cast of MGUH 33145. Height 26.0 mm. J. Silicone cast of lectotype MGUH 91 figured by Ravn (1902, pl. I: 17). Width 11.7 mm. K. Silicone cast of MGUH 93, figured type for Cerithium sartorii Ravn, 1902. Height 7.1 mm. L. Dzikella? sp., Silicone cast of MGUH 33146. Width 6.0 mm. M–Q. Amaurellina ravni n. sp. M–N. Silicone cast of holotype MGUH 33147. Width 10.3 mm. O. The internal mould of paratype MGUH 33148. Width 13.2 mm. P. Paratype MGUH 33149, a mould with replaced shell. Height 12.8 mm. Q. Silicone cast of paratype MGUH 33150. Width of picture 3.0 mm. R. Trochocerithium sp., Silicone cast of MGUH 33151. Width 9.0 mm. S–W. Galericulus sp. S–T. Internal mould ØSM.10042-311. Length 5.8 mm. U. Internal mould MGUH 33152. Width 8.5 mm. V–W. Internal mould and external cast of MGUH 33153. Length 10.3 mm. Width of figure W 7.7 mm. X. Natica sp. A. Silicone cast of MGUH 33154. Width 7.9 mm.