Danoceras vohilaidense, Kröger, 2025

Kröger, Björn, 2025, The Lyckholm acme of cephalopods - Review of the late Katian (Vormsi-Pirgu regional stages) Ordovician cephalopods of Estonia, European Journal of Taxonomy 978, pp. 1-169 : 65-66

Danoceras vohilaidense sp. nov.

urn:lsid:zoobank.org:act:7564A1C1-841D-4E29-A39F-73A476806D3D

Fig. 24E

Diagnosis

Danoceras with compressed oval conch-cross section (CHI = 1.6) with narrow, almost angular, dorsal, and ventral margins; mature body chamber with maximum conch height near its base with height of ca 53 mm and height length ratio of ca 1.3; conch surface, with distinct constriction near peristome and amphora-like apertural opening.

Etymology

Refers to the type locality.

Type material

Holotype

ESTONIA • Vohilaid Island, Vohilaid shore (E); Adila Formation , Pirgu Regional Stage; GIT 878-273 .

Paratypes

ESTONIA • 2 specs; same data as for holotype; GIT 878-274 , GIT 878-278 .

Description

In all three specimens the outer shell is not preserved. In the holotype and in GIT 878-274, the conch height is 52–53 mm at the base of the body chamber, and at the peristome 48 mm, the conch width is 34 mm at the base of the body chamber (CHI = 1.56), and the length of the body chamber 40 mm. A slight taphonomic compression can be assumed, the conch cross section is oval with narrow, almost angular, dorsal, and ventral margins. In the holotype, the phragmocone has a height of 51– 47 mm at a length of 28 mm (angle of expansion = 8°). The sutures form very shallow lateral lobes, and the septal foramen is close to the conch margin with a width of 3.5 mm.

Remarks

The two mature body chambers (holotype and in specimen GIT 878-274) are almost identical in size and shape, identifying them as belonging to the same species. They are larger than those known from other Estonian Danoceras , and approximately similar to that of D. broeggeri Strand, 1934 from the Upper Isotelus Limestone of Norway. The latter differs in size and CHI (mature body chamber height 56 mm, CHI 1.3–1.4).

Figures

Fig. 24. Danoceras Troedsson, 1926 from the Vormsi–Pirgu regional stages, Estonia. A. Danoceras oviforme sp. nov., holotype GIT 878-108, from Moe trench, Vormsi Regional Stage, lateral view. B. Danoceras breve Strand, 1934, holotype GIT 426-988, from Haapsalu holm, Haapsalu, Pirgu Regional Stage, lateral view. C. Danoceras oviforme sp. nov., specimen GIT 80-510, from Piirsalu quarry, Pirgu Regional Stage, lateral view prosiphuncular side toward right. D. Danoceras piersalense (Teichert, 1930) comb. nov., specimen GIT 840-271, from Hosholm shore (tower), Vormsi Island, lateral view. E. Danoceras vohilaidense sp. nov., holotype GIT 878-273, from Vohilaid shore (E), Vohilaid Island, Pirgu Regional Stage, lateral view, prosiphuncular side left.F–H. Danoceras piersalense specimen GIT 840-93, from Hosholm shore (tower), Vormsi Island, Pirgu Regional Stage. F. Lateral view. G. Adapical view, prosiphuncular side to the right. H. Specimen TUG 1745-302, from Pirgu River outcrop, Pirgu Regional Stage, lateral view. Scale bar = 10 mm, same scale in all figures.