Colubrellopsis, Bandel, 2007

Colubrellopsis ? sp.

( Figs 51–53 View Figs 51–71 )

Material – Single (GBA 2019/009/0031), badly worn specimen from a box without label but the preservation suggests its origin from the Hierlatz Limestone.

Measurements – GBA 2019/009/0031, W = 13.6 mm, H = 15.5 mm.

Description – The only specimen has a thick walled neritiform shell of three whorls with a depressed early shell that is homeostrophic to the teleoconch. All whorls are convex and an impressed suture separates them. Near the peristome, the last whorl slopes toward the suture in a narrow area, widening in direction of the aperture. The aperture is suborbicular; only the short columellar and the long parietal lip break the almost regular circle of the outer lip. The parietal lip appears as a thin shell encrustation that is just slightly concave on the apertural side. The basal ridge and the outer rim of the inner lip are separated by a narrow furrow; no trace of an umbilicus is visible. Outer lip is sharp and strongly prosocline; the whole apertural complex joins nearly tangentially to the last whorl.

Only collabral ornament is observable on the shell that consists of stronger and evenly spaced ribs, extending suture to the basal ridge with weaker riblets and threads of the same length in the interspaces of the formers. From about the last half whorl, the strongest elements are already lacking.

Remarks – In Neritopsoidea , BANDEL (2007) established Colubrellopsis and a very similar genus, Ladinaticella Bandel, 2007 ( Tricolnaticopsidae Bandel, 2007 ). Actually the depressed early whorls that seem to indicate also a similarly whorled protoconch supported to choose the name Colubrellopsis ? sp. for the Hierlatz Alpe find. Since its poor preservation, many details have been uncertain or unknown, therefore the generic attribution may alter; the specimen probably represents a new species.

Occurrence – Within Sinemurian to lowermost Pliensbachian (Lower Jurassic) part of the Hierlatz Limestone Formation in Hierlatz Alpe, Hallstatt, Austria.