Richardsonoceras sinuososeptatum
Sugerowana cytacja: Moczyński 2019. Richardsonoceras sinuososeptatum (Roemer, 1861) Ikonoteka (http://ikonoteka.paleo.pan.pl/xwiki/bin/export/Species/Richardsonoceras+sinuososeptatum)
Diagnoza Relatively short, exogastrically curved conchs with almond-shaped cross section, ventral side sharp; thick growth lines arched in outline and running obliquely, forming a sharp sinus at the ventral side. Porównanie Roemer's only preserved specimen attains 32 mm in diameter of immature phragmocone, which resembles the holotype of Beloitoceras heterocurvatum Strand, 1935. There is a close resemblance also in the aperture outline, as judged from the traces of growth lines discernible on the mould of the phragmocone. The mature living chamber of B. heterocurvatum declines in diameter adaperturally, as in the type species of the genus. The holotype of B. heterocurvatum agrees with the paratype of C. sinuososeptatum in the shape of connecting rings. One may thus suppose that the specimens are conspecific. Autekologia Występowanie geograficzne Zasięg czasowy Materiały muzealne Literatura Dzik, J. 1984. Phylogeny of the Nautiloidea. Palaeontologia Polonica 45, 1-255. Strand, T. 1935. The Upper Ordovician cephalopods of the Oslo area. Norsk Geologisk Tidsskrift 14, 1-117. |
|