Campanile selandicum ( Lundgren, 1867 )

Hansen, Thomas, 2019, Gastropods from the Cretaceous-Palaeogene boundary in Denmark, Zootaxa 4654 (1), pp. 1-196 : 86-87

Campanile selandicum ( Lundgren, 1867)

Figs 24 B–D

1867 Cerithium selandicum Lundgren : 17, pl. 1, fig. 2.

1902 Cerithium pseudotelescopium n. sp. —Ravn: 219–220, pl. 1, figs 13–14.

1902 Cerithium selandicum Lundgren—Ravn : 220–221, pl. 1, figs 15–16.

1933 Cerithium ( Campanile ?) pseudotelescopium Ravn—Ravn : 45, pl. 4, fig. 8a–b.

1933 Metacerithium ? selandicum Lundgren—Ravn : 46.

2014 Campanile ? pseudotelescopium ( Ravn, 1902) —Lauridsen & Schnetler: 48, fig. 32.

Diagnosis. Columella with single strong fold. Teleoconch sculpture on early whorls consisting of two or three distinct spiral rows of tubercles. Suture bordered by two rows, while last row runs on adapical half of whorl, connected by weak transverse rib to adapical tubercle row. Later whorls with fine spiral ribs.

Material from the boundary layers. MGUH 33140, MGUH 33141 and ØSM.10042-129. The old collections at the Natural History Museum of Denmark includes another five uncatalogued moulds.

Type stratum and type locality. The middle Danian Faxekalk at Limhamn, southern Sweden .

Occurrence. From the lower Danian Cerithium Limestone Member and up to the middle Danian Faxe Limestone in Sweden and Denmark. At Stevns Klint it is found in the Cerithium Limestone Member and succeeding Korsnaeb Member. A specimen has been found by C. Heinberg in the contemporaneous ‘dead layer’ at Vokslev, Northern Jutland.

Description of Cerithium Limestone material. Protoconch not known. Teleoconch spire high, slender with low, flat whorls and sharp keel, whorl height corresponding to one third the width. Suture enhanced by spiral ribs on early growth stages, becoming thin and shallow on later growth stages. Last whorls more inflated with keel close to abapical suture. Base nearly perpendicular to whorl side, flat to slightly concave, becoming more convex on last whorl. Aperture subrectangular with short columella carrying single sharp fold centrally, bordered abapically by deep canal.

Teleoconch sculpture variable, on early growth stages consisting of two primary beaded spiral ribs, the typically strongest at adapical suture, the other on keel at abapical suture. Primary spiral ribs separated by several weaker secondary ribs, the adapical one being the strongest; secondary ribs increasing in number on later whorls while becoming fainter. Tubercles, reflecting slightly opisthocyrt growth lines, generally merging into transverse ribs on adapical part of whorl, fading out abapically, often merging with tubercles on abapical primary spiral rib; number of adapical tubercles approximately 15 in a half whorl on second last whorl of MGUH 33141 and 18 in abapical row. Transverse ribs decreasing in strength and length with increasing whorl number. Base with single primary smooth spiral rib located close to keel at transition to flat part of base and axially succeeded by faint secondary spiral ribs. Sculpture on later growth stages changing to one of moderately fine, unbeaded spiral ribs only, the exact rib-configuration varying from specimen to specimen, but tending towards a fainter ribbing centrally on whorl. Base with weak spiral ribs.

Measurements. Most complete specimen, MGUH 33140, 32.7 mm high and 11.4 mm wide, consisting of 12 teleoconch whorls.

Remarks. The taxon is variable with regard to shell sculpture, varying between forms with only spiral ribs to others with two or three stronger spiral rows of tubercles, the adapical two connected by more or less weak transverse ribs. The transverse sculpture is typically most prominent on early teleoconch whorls, fading out on later whorls. The wide variability has led to the erection of the subjective junior synonym Campanile pseudotelescopium ( Ravn, 1902) . It was thought to differ from C. selandicum ( Lundgren, 1867) by having only one subsutural tubercle row and by the whorls being generally slightly higher and with a more abapical location of the columellar fold. An examination of the material stored at the Geological Museum of Copenhagen together with new material figured by Damholt et al. (2010) do not support such a division.

The taxon belongs to Campanile and not Metacerithium due to the well developed columellar fold and the strongly flattened base on early whorls.

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.