Detailed Parkinsonia Ammonite from Germany

Description: Parkinsonia are used as an index fossil to demarcate a geological time zone in the Jurassic period. Presented is a beautiful and large example of the classic species. It is wonderfully preserved, with its calcite skin still intact. Note the white to brown colors represented. There has been no crushing or distortion to the specimen. It rests comfortably on a flat matrix base. The keel has a slight indentation. This one would definitely compliment any serious ammonite collection.

Background: BAJOCIAN, in geology, the name proposed in 1849 by d'Orbigny for the rocks of Middle Jurassic age which are well developed in the neighborhood of Bayeux, Calvados. The Bajocian stage is practically equivalent to the Inferior Oolite of British geologists. It corresponds fairly closely with the Lower and Middle Brown Jura of Quenstedt, and with the Dogger of Oppel. By means of the fossil ammonites the Bajocia strata have been subdivided into the following zones, in descending order: Zone of Parkinsonia Parkinsoni and Cosmoceras garantianum "Coeloceras subcoronatum (Humphriesianum)" Sonninia Romani "Stephaeoceras Sowerbyi" Harpoceras concavum Murchisonae _ Substage Aalenien opalinum = of Mayer-Eymar.