Eulima, Risso, 1826

Hansen, Thomas, 2019, Gastropods from the Cretaceous-Palaeogene boundary in Denmark, Zootaxa 4654 (1), pp. 1-196 : 105-106

Eulima ? danica Ravn, 1933

Figs 26 Y–Z

1933 Eulima (Polygyreulima) danica n. sp. Ravn: 41, pl. IV, figs 1a–b, 2a–b.

2014 Eulima (Polygyreulima) danica Ravn, 1933 —Lauridsen & Schnetler: 68, fig. 83A–D.

Diagnosis. Shell relatively high, straight, with highly flattened whorls separated by nearly invisible sutures. Transition to base moderately convex.Aperture relatively high and narrow with very sharp upper angle and gently sigmoid inner side. Columellar lip distinct with evenly rounded outer margin. Outer lip gently sigmoid.

Material. Material examined herein consists of holotype MGUH 3148 and paratype MGUH 3149 from the Danian ‘Naesekalk’, specimens MGUH 33180, MGUH 33181, ØSM.10042-313-a and b, three specimens from the informally catalogued samples SR.575, SH.141.A–B and SH.169.B, and five uncatalogued moulds from the lower Danian Cerithium Limestone. The latter specimens are deposited in the old collections at the Natural History Museum of Denmark.

Type stratum and type locality. The middle Danian ‘ Naesekalk’ at Faxe Quarry, Sealand, Denmark .

Occurrence. Eulima ? danica is known from an unspecified level within the lower Danian Cerithium Limestone Member at Skeldervig and from the lower 10 cm of the Cerithium Limestone Member at Højerup Church, Stevns Klint. The type material belongs to the middle Danian ‘Naesekalk’ in Faxe Quarry, Denmark. In addition a single specimen, ØSM.10042-313-a + b, is known from the ‘Krabbelaget’, a hardground located two metres up in the Korsnaeb Member. A further specimen in the collections of C. Heinberg comes from the lower Danian ‘dead layer’ at Vokslev, Northern Jutland.

Description. Slender shell generally nearly straight, awl-shaped conical with a height corresponding to around 3.7 times the width. Protoconch consisting of 1 3/4 smooth and moderately convex whorls. Protoconch differing only slightly from teleoconch by a distinctly stronger whorl convexity. Teleoconch whorls relatively high and flat with a smooth surface except for the weak growth lines. A few moderately weak incremental scars may be present, while a false suture is absent or at most very faintly developed slightly below the shallow suture. Aperture high and narrow, the height corresponding to nearly 2.6 times the width. Outer lip straight in frontal view, in lateral view slightly prosocline, strongly projecting with strongest projection below mid-line. Base of aperture slightly pointed. Parietal callus thin but distinct. Umbilicus absent.

Measurements. Shell of most complete specimen from the Cerithium Limestone , MGUH 33180, 9.2 mm high and 2.5 mm wide with an aperture measuring 3.1 mm in height and 1.2 mm in width and consisting of 7 ½ teleoconch whorls. Last whorl 4.8 mm in height.

Remarks. Eulima ? danica could also belong to the closely related genus Melanella Bowdich, 1822 , but differs by the relative height of the aperture corresponding to nearly 2.6 times the width, whereas Melanella typically is characterized by an aperture H/W ratio of less than 2.4 ( Bouchet & Waren 1986) and by a more convex outer lip profile (pers. comm. A. Warén, 2009). Another possible genus is Polygyreulima Sacco, 1892, which generally is characterized by a relatively slender spire like the present species, but the very straight outer lip profile would rather suggest an assignment to Eulima (pers. comm. A. Warén, 2009).

Eulima ? danica resembles the Late Cretaceous Eulima gracilistylis Sohl, 1964a and E. persimplicata ( Wade, 1926) from Mississippi, USA, but differs in the narrower aperture and, with regard to E. gracilistylis also in a less curved inner lip.

Recently Lauridsen and Schnetler (2014: p. 68) listed paratype MGUH 3149 figured in Ravn (1933: pl. IV: 2a–b) as the holotype. This is probably an error as Ravn (1933) himself stated the holotype to be the one figured on plate IV, fig. 1 (in other words specimen MGUH 3148).

Figures

FIGURE 26. A–B. Alvania sp. A. Silicone cast of MGUH 33164. Width 1.5 mm. C. Alvania sp. B. Silicone cast of MGUH 33165. Width 0.8 mm. D. Zebina sp., Wax cast of MGUH 33166. Width 0.9 mm. E–H. Ceratia rodvigensis n. sp. E–F. Silicone cast of holotype MGUH 33167. Width 0.8 mm. G–H. Silicone cast of paratype MGUH 33168. Width 0.9 mm. I–J. Ceratia? sp. I. Mould of MGUH 33169. Width 0.9 mm. J. Silicone cast of MGUH 33170. Height 1.1 mm. K. Anchura sp., Silicone cast of MGUH 33171. Width 8.6 mm. L–M. Columbellaria tuberculosa (Binkhorst, 1861). Silicone cast of ØSM.10042-202-a–c. Width 5.2 mm, height 5.9 mm. N. Tylostoma? sp., inner mould MGUH 33172. Width 19.9 mm. O–P. Cassidae genus et sp. indet. Silicone cast and internal mould of ØSM.10042-315-a–b and c, respectively. Width 9.2 and 8.6 respectively. Q–U. Sassia faxense Ravn, 1933. Q. Detail of apex of MGUH 33173. Width of protoconch 1.4 mm. R. Silicone cast of MGUH 33174. Width 6.0 mm. S. Silicone cast of MGUH 33175. Width 6.5 mm. T. Silicone cast of MGUH 33176. Width 7.8 mm. U. Silicone cast of MGUH 33177. Width 5.2 mm. V–X. Hipponix sp. V–W. Internal mould MGUH 33178. Length 23.8 mm, width 19.5 mm. X. Inner mould MGUH 33179. Width 19.1 mm. Y–Z. Eulima? danica Ravn, 1933. Y. Silicone cast of MGUH 33180. Width 2.5 mm. Z. Silicone cast of MGUH 33181. Width 2.0 mm. AE. Eulima? sp., Mould MGUH 33182. Width 1.3 mm.