Babylonella, Conrad, 1865

Hansen, Thomas, 2019, Gastropods from the Cretaceous-Palaeogene boundary in Denmark, Zootaxa 4654 (1), pp. 1-196 : 156

Babylonella sp.

Figs 33 M–N

Material. MGUH 33293, MGUH 33294 and possibly an incomplete external mould with the informal sample number SS.213.A–C.

Occurrence. The Cerithium Limestone Member at Højerup and perhaps Flagbanken, Stevns Klint.

Description. Protoconch conical with nearly planispiral apex. It consists of just over three convex and smooth whorls, with a sharp transition to teleoconch marked by the appearance of transverse ribs. Width 0.95 mm; height slightly lower.

Teleoconch fairly slender with highly convex whorls and a marked shoulder and adapical ramp; whorls twice as wide as high. Last whorl taking up approximately 70 % of the shell height, abapically forming short canal. Columella with two moderately weak folds.

Teleoconch sculpture dominated by 10 to 11 sharp, prosocline transverse ribs, fading out adapically and abapically on ramp and base; ribs highest at shoulder. Ribs crossed by four or five fine spiral threads from shoulder and down on spire whorl, and two additional but weaker spiral threads on ramp. Last whorl covered by 12 more or less evenly distributed primary spiral threads and two weaker ones alternating with the original two spiral threads on ramp.

Measurements. MGUH 33293 is 2.6 mm high and 1.6 mm wide, consisting of protoconch and two teleoconch whorls.

Remarks. This taxon has a strong morphological resemblance to the Selandian Babylonella ravni ( Glibert, 1960) from Denmark, but the protoconch has more whorls and may be slightly more conical in outline, while the number of transverse teleoconch ribs per whorl is in the low end.

Figures

FIGURE 33. A. Mangeliid genus et sp. indet., Silicone cast of MGUH 33286. Protoconch width 0.8 mm. B–E. Tatara pseudosassia n. sp. B–C. Silicone cast of holotype MGUH 33287. Width 4.8 mm. D. Silicone cast of paratype MGUH 33288. Width 3.7 mm. E. Internal mould of last whorl of paratype MGUH 33289. Width 5.9 mm. F–H. Tatara sp., Silicone cast and internal moulds of MGUH 33290. Widths 10.4, 9.9 and 9.9 mm respectively. I–L. Sveltella sp. I–J. Silicone cast of MGUH 33291. Width of teleoconch 3.0 mm. Width of picture J 3.5 mm. K–L. Silicone cast of MGUH 33292. Widths 3.1 mm. M–N. Babylonella sp. M. Silicone cast of MGUH 33293. Width 1.6 mm. Picture by S.L. Jakobsen. N. Silicone cast of MGUH 33294. Width 1.7 mm. O–R. Unitas heinbergi n. sp. O–Q. Silicone cast of holotype MGUH 33295. Widths 3.0, 3.0 (vertical on figure) and 2.8 mm respectively. R. Silicone cast of paratype MGUH 33296. Width 2.9 mm.