Skenea, Fleming, 1825

Hansen, Thomas, 2019, Gastropods from the Cretaceous-Palaeogene boundary in Denmark, Zootaxa 4654 (1), pp. 1-196 : 74

Skenea sp.

Figs 22 G–I

Material. MGUH 33113, MGUH 33114, ØSM.10042-194 and a mould in the informally numbered sample SR.1101 deposited at the Natural History Museum of Denmark.

Occurrence. Lithified top of the Maastrichtian Højerup Member of the Tor Formation at Rødvig and Holtug Quarry, Stevns Klint.

Description. Shell low spired and umbilical, consisting of at least four thin-shelled and loosely coiled whorls separated by deep suture. Transition between protoconch and teleoconch obscure. Whorls smooth, highly convex with weak peripheral keel on first whorl fading away on last; whorl expansion initially slow, becoming pronounced on last whorl. Base strongly convex with wide and deep umbilicus, width approximating 1/5 shell width. Aperture circular in outline, height corresponding to around 4/5 of shell height.

Measurements. MGUH 33114 is 10.2 mm wide and at least 6.8 mm high with two preserved teleoconch whorls.

Remarks. Skenea sp. looks quite a lot like the extant type species Skenea serpuloides (Montagu) except for the smooth whorls and lower spire. It differs from the Middle Palaeocene Circulus sp. of Kollmann & Peel (1983: fig. 38) from Greenland by the smooth and more strongly expanding teleoconch whorls.

Figures

FIGURE 22. A. Phorcus sp., Silicone cast of MGUH 33109. Exposed width 2.2 mm. B–C. Stomatella sp., External mould of MGUH 33110. Figure B has been colour inverted and mirrored to show it in positive. Width 1.5 mm. D–F. Solariella sp. D–E. Silicone cast of MGUH 33111. Width 6.2 mm. F. Silicone cast of aperture of MGUH 33112. Width 5.95 mm. G–I. Skenea sp. G–H. Inner mould of MGUH 33113. Width 5.2 mm. I. Inner mould of MGUH 33114. Width 10.2 mm. J–K. Leucorhynchia sp., Silicone cast of MGUH 33115. Width 2.4 mm. L–N. Tectus? indecorus n. sp., L. Umbilical view of inner mould of paratype ØSM.10042-327-b. Width 19.7 mm. M–N. Silicone cast of holotype MGUH 33116. Width 1.7 mm. O–P. Homalopoma sp., Silicone cast and inner mould of MGUH 33117. Width 9.6, 6.9 mm respectively. Q. Calliomphalus (Calliomphalus) sp., Silicone cast of MGUH 33118. Width 3.1 mm. R–U. Arene jakobseni n. sp. R–T. Silicone cast of holotype MGUH 33119. Width 8.6 mm. U. Silicone cast of paratype MGUH 33120. Width of aperture 4.8 mm.