Desmoceras (Pseudouhligella) intrapunctatum n. sp. (Ammonoidea) aus dem Unter-Albium von NW-Madagaskar mit Ritzstreifen

The new ammonoid speciesDesmoceras (Pseudouhligella) intrapunctatum (DesmoceratoideaZittel, 1895) is described and figured from the dark glauconitic marls of the Lower Albian of Ambatolafia (Mahajanga Basin of northwestern Madagascar). On the molds of its body chamber a well developed system of dotted lines is visible originally described from Palaeozoic ammonoids and nautiloids (= ?Ritzstreifen“Sandberger & Sandberger 1850 sensuTozer 1972). These internal shell structures have been originated by small ridges of the inner prismatic layer as the result of an incomplete mineralization. “Ritzstreifen” could not have observed in any other ammonoid species accompanied withDesmoceras (Pseudouhligella) intrapunctatum, despite of the same excellent aragonitic shell preservation. Therefore, this unique character is interpreted as taxonomically significant on species level.