A. Marok  , A. Sebane  , L. Mekahli  , S. Elmi  , 
    Quantitative Biogeography of the Upper Aalenian-Lower Bajocian Ammonites (Western Tethys): Application of the Multivariate Methods,
    Online Journal of Earth Sciences,
    Volume 1,Issue 2,
    2007,
    Pages 113-118,
    ISSN 1991-7708,
    ojesci.2007.113.118,
    (https://makhillpublications.co/view-article.php?doi=ojesci.2007.113.118)
    Abstract: In order to quantify the biogeographic dynamics of ammonites faunas of Upper Aalenian-Lower Bajocian, 9 areas located in Western Tethys were analyzed by the multivariate method (Principal coordinate analysis and calculating similarity index and distance). The results obtained reveal the following facts: -the stability and resemblance   during the time of faunas of the Betic Cordillera, Iberian Cordillera, central High Atlas and the Lusitanian basin,-the fluctuation starting from the Laeviuscula zone of Dorset-Somerset, the basin of South-east of France and the folded Middle Atlas. This fluctuation is controlled by several factors: paleotemperature, eustatism, paleogeography, and trophic conditions,-the isolation of faunas of Beni Snassen and Umbria-Marche Apennines.
    Keywords: Biogeography;ammonites;upper aalenian-lower bajocian;multivariate method