Pyrgopolon (Septenaria) cf. tricostata (GOLDFUSS)

Kočí, Tomáš, 2012, Sabellidae And Serpulidae (Polychaeta, Canalipalpata) From The Locality Kaňk - Na Vrších In Kutná Hora (Upper Cenomanian - Lower Turonian, Bohemian Cretaceous Basin - The Czech Republic), Acta Musei Nationalis Pragae Series B 68 (1 - 2), pp. 7-14 : 10-11

Pyrgopolon (Septenaria) cf. tricostata (GOLDFUSS)

Pl. 1, figs 4a-b pars

1967

pars

1984

2010

1910 Burtinella (?) Reussi m. – Weinzettl: pp. 23-24, pl. 3, fig. 48, 50.

Ditrupa tricostata (GOLDFUSS), 1841 . – Ziegler: pp. 14-18, figs 2-3.

1984 Ditrupa subtorquata (MÜNSTER), 1831 . – Ziegler: pp. 238-239,

Ditrupa tricostata (GOLDFUSS), 1841 . – Ziegler: p. 239, pl. 6, figs 8-9.

Pyrgopolon (Septenaria) cf. tricostata (GOLDFUSS) . – Kočí: pp. 124-125, figs 5-6.

M a t e r i a l: One complete specimen, 30 specimens of the free anterior tube portion, 4 incomplete specimens of the free anterior tube portion and attached posterior tube portion, 26 tube fragments.

D e s c r i p t i o n: Posterior tube portion is attached to the substrate; the cross-section of this part is triangular, and there is one median keel. Anterior tube portion freely erect with five rounded keels respectively, four lobes and a very fine distinct median keel. Diameter of the anterior tube portion 2.6 mm. Lumen circular, 2.4 mm in diameter. A groove is present on the underside between the lower lateral lobes.

D i s c u s s i o n: These specimens are very similar to Ditrupa (Pentaditrupa) iubata REGENHARDT, 1961 from the Turonian of Troo , Loire-et-Cher , France, which has four rounded keels (lobes) and a very distinct dorsal keel. The cross-section is pentangular and there is no transversal ornamentation. The holotype differs from the specimens from Kaňk due to its larger median keel, and from Regenhardt´s description it is clear that the anterior tube portion was still attached to the substrate. In contrast the specimens from Kaňk have anterior tube portions which are free and erect above the substrate .

Moreover, the specimens from Kaňk do not belong to the typical tricostata species from the Cenomanian of Essen in Germany. According to their morphological features they belong to the subgenus Pyrgopolon (Septenaria) , see ( Jäger, 1983, 2005; Jäger and Breton, 2002). In the BCB, Pyrgopolon (Septenaria) cf. tricostata was found in nearshore localities, e.g. Velim, Nová Ves, Kamajka, and Chrtníky.

The specimen from Nová Ves near Kolín which Ziegler (1984) described as Ditrupa iubata (REGENHARDT) (NM- O5391) is not serpulid. The specimen which according to its registration number NM-O5363 should be, is not the original specimen figured by Ziegler (1984) on his pl. 6, fig. 7 as Ditrupa subtorquata from Nová Ves. In addition, the original specimens NM-O5394 and NM-O5395 determined by Ziegler as Ditrupa tricostata from Velim, all are very similar to the specimens from Kaňk and represent the same species, which is, however, neither subtorquata nor tricostata . Ziegler (1967, 1984) described specimens from the BCB as belonging to the genus Ditrupa , but this is a misinterpretation, because in contrast to Ditrupa , the posterior tube portion is attached to the substrate, whereas the shape is similar to the genus Pyrgopolon and especially the subgenus Septenaria . The species Ditrupa subtorquata and Ditrupa schlotheimi clearly belong to the genus Ditrupa .