Coelostylina, Kittl, 1894

Coelostylina View in CoL ? sp1.

( Figs 68–69 View Figs 51–71 )

Material – Single specimen (GBA 2019/009/0044) from a box, labelled as Chemnitzia sp.

Measurements – D = ~ 16 mm, spiral angle: ~35°.

Description – The remnants represent a thin shelled species, having moderately turriculate spire with about 35° coiling angle in the latest growth phase. Three whorls are visible, which show a slightly ovate outline, so the apical angle must be considerably wider. The whorls are convex and an impressed suture separates them. A strongly rounded angulation is observable slightly above the suture on the earlier whorls, that is absent from the last whorl. The periphery nearly coincides with the midwhorl on the last whorl but it is nearer to the lower suture on the former whorls.

A little, eroded portion of the shell shows rather sparse, orthocline, and feebly opisthocyrt grooves on its surface and much wider, smooth, and flat bars in the interspaces under magnification. Regular corrugation of the margins of the bars may indicate dense, delicate spiral lineation in less damaged stage.

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