Warburgoceras longitudinale (Angelin in Angelin & Lindström, 1880 ) Kröger, 2013

Kröger, Björn, 2013, The cephalopods of the Boda Limestone, Late Ordovician, of Dalarna, Sweden, European Journal of Taxonomy 41, pp. 1-110 : 83-84

Warburgoceras longitudinale (Angelin in Angelin & Lindström, 1880) comb. nov.

Figs 18F , 39C

Cyrtoceras longitudinale Angelin in Angelin & Lindström, 1880: 11 , pl. 16, fig. 5.

Uranoceras (?) longitudinale – Mutvei 1957: 245, text-figs 6c, 7b, 10, 11, 20, 21, pl. 4, fig. 3, pls 6, 7, 17, 18. ― Dzik & Korn 1992: 84, 85, text-fig. 1.

Uranoceras longitudinale – Dzik 1984: 150, 154, text-fig. 59.2.

Diagnosis

Same as for genus by monotypy.

Type locality and horizon

Osmundsberget, Dalarna, Sweden, Boda Limestone, Boda Core Member, late Katian, Ordovician.

Material

Four specimens, two from Kallholn ( PMU 26919, 26921), one from Osmundsberget ( NRM Mo 154065) and one from Unskarsheden ( PMU 26920); Boda Limestone, late Katian, Dalarna, Sweden.

Remarks

This species was extensively described by Mutvei (1957). Additionally, the ventromyarian periphract was figured in three specimens with the mature body chamber preserved ( Mutvei 1957: pl. 4.3, fig. 4; pls 6, 7). Two more specimens with complete mature body chambers are in the collections of the NMR and PMU. Both body chambers are nearly identical in maximum conch height (58 mm), which is reached at the peristome. The body chamber contracts only very slightly close to the peristome and has a length of 90–100 mm (NRM Mo 154065, PMU 26919) (height/length ratio of body chamber ca. 0.6).

Comparison

Warburgoceras longitudinale comb. nov. is very similar to Redpathoceras bullatum sp. nov. with respect to ornamentation (both species have a similar distinctively longitudinally lirate surface; Fig. 18F ), and are identical in angle of expansion, conch curvature, conch cross section and mature size ( Fig. 39C ). They differ, however, in two main aspects: (1) the mature body chamber of R. bullatum sp. nov. is inflated, with a maximum height at the mid-length, whereas the body chamber of W. longitudinale comb. nov. opens gradually, (2) the conch of R. bullatum sp. nov. displays deeply concave septa of truncation at regular distances. This similarity strongly suggests a close phylogenetic relationship between the two species, genera and higher taxa to which they belong (see discussion above).

Stratigraphic and geographic range

Boda Limestone, late Katian, Dalarna, Sweden.

Figures

Fig. 18. Shell ornamentation of selected Cephalopoda of the Boda Formation. A. Order, gen. et sp. indet., PMU 26950, Kallholn, lateral view. B. Palaeodawsonocerina? nicolletoides sp. nov., PMU 26727, holotype, Kallholn. C. Palaeodawsonocerina senckenbergi (Teichert, 1930), PMU 26718, Kallholn. D. Geisonoceras wegelini (Angelin in Angelin & Lindström, 1880) comb. nov., PMU 26745, Unskarsheden. E. Pleurorthoceras osmundsbergense sp. nov., NRM-PZ Mo 150126, holotype, Osmundsberget. F. Warburgoceras longitudinale (Angelin in Angelin & Lindström, 1880) comb. nov., NRM-PZ Mo 154065, Unskarsheden. G. Redpathoceras depressum sp. nov., PMU 26931, Kallholn. Scale bar = 5 mm for all figures.

Fig. 39. Ascocerida and Uranoceratidae of the Boda Limestone. A-B. Redpathoceras bullatum sp. nov. A. PMU 26923, holotype, Kallholn; mature truncated body chamber, lateral view. B. Same specimen, view from antispihuncular side. C. Warburgoceras longitudinale (Angelin in Angelin & Lindström, 1880) comb. nov., NRM-PZ Mo 154065, Unskarsheden; mature body chamber and part of phragmocone in lateral view. D-E. Probillingsites scandinavicum sp. nov., PMU 26922, holotype, Kallholn. D. Mature truncated body chamber, lateral view. E. Same specimen, view from prosiphuncular side. F. Schuchertoceras fryi sp. nov., PMU 24744, holotype, Kalllholn, lateral view. Scale bars: A-E =10 mm; F = 10 mm.