Species
Palaeodawsonocerina nicolletoides Kröger, 2013
Taxon description
Kröger & Isakar, 2006
Diagnosis. Straight, slightly compressed with very low apical angle of approximately 1°––2°. Adult dorsoventral diameter approximately 25 mm, with five to six annulations at a distance that equates to the corresponding shell diameter in adult specimens. Annulations straight or very slightly oblique toward the growth direction and regularly spaced. Very fine growth lines, about 50 per cycle of annulations. Very fine longitudinal striae or raised lines, about five to seven per mm. Suture line at the ridges of the annulations. Parallel sutures and annulations. Siphuncle central, slightly expanded within the chambers. Septal perforation about 0.07 of the shell diametre.
Synonyymit
2013 Palaeodawsonocerina? nicolletoides sp. nov. — Kröger , pp. 36, fig. 12D-E; 18D
Aiheeseen liittyvät julkaisut
Kröger, B. 2013. The cephalopods of the Boda Limestone, Late Ordovician, of Dalarna, Sweden. European Journal of Taxonomy 41, 41, 1-110. DOI:10.5852/ejt.2013.41
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Luokittelu
Organism group | Biota |
Kingdom | Animalia |
Phylum | Mollusca |
Class | Cephalopoda |
Subclass | Orthoceratia |
Order | Orthocerida |
Suborder | Orthoceratina |
Family | Dawsonoceratidae |
Genus | Palaeodawsonocerina |
Species | nicolletoides |
senckenbergi |
Levinneisyys ja viitteet
- Kröger, 2013 Kallholn quarry Katian