Trilobiten.de

[Jens]

Hier mal etwas anderes. Habe ein pdf gefunden, welches für Geschiebesammler hilfreich sein kann, wenn es um die Bestimmung von Orthoceraten, also Nautiloiden geht.

Es ist von Björn Kröger. Er hat auch Geschiebematerial aus dem Müritz-Museum Waren, Hamburg und Greifswald berücksichtigt.

Björn Kröger (2004): Revision of Middle Ordovician orthoceratacean nautiloids from Baltoscandia. - Acta Palaeontologica Polonica 49 (1), 2004: 57-74, 13 Fig.

The fauna of the Baltoscandic Orthocerataceae is important because it fills a documentary gap between the Lower Ordovician fauna of North America and the upper Middle Ordovician fauna of China and North America. A revision of the Orthoceratidae, Geisonoceratidae, and Arionoceratidae is given on a material of more than 450 specimens. Intraspecific and ontogenetic variations were observed. The following new taxa are erected: Plagiostomoceras fragile sp. nov., Archigeisonoceras repplingense sp. nov., Archigeisonoceras picus sp. nov. Archigeisonoceras folkeslundense sp. nov., Nilssonoceras latisiphonatum gen. et sp. nov., Kinnekulloceras kinnekulense gen. et sp. nov., and Arionoceras lotskirkense sp. nov. The genus Archigeisonoceras is described for the first time in the Baltoscandic area and the oldest occurrence of the genus Arionoceras is documented from the Middle Ordovician of Baltoscandia. It is shown that the endosiphuncular deposits of the Middle Ordovician orthoceratacaceans are highly variable and widespread in the apical parts of the phragmocone.

http://app.pan.pl/acta49/app49-057.pdf

Grüsse,

Jens