New findings of lower Aptian charophytes from the Southern High Plateaus (Eastern Meseta, Morocco): biostratigraphic and biogeographic significance

Abstract

Two stratigraphic sections of the Southern High Plateaus (Eastern Meseta, Morocco) were sampled for the charophyte study. Seven clavatoracean taxa are described and illustrated from the Dekar 1 and Dekar 2 formations, including Echinochara lazarii, Atopochara trivolvis var. trivolvis, Clavator grovesii var. jiuquanensis, Clavator grovesii var. corrugatus, Clavator harrisii var. harrisii, Clavator harrisii var. reyi, and Clavator harrisii var. zavialensis. This assemblage is assigned to the upper part of the Eurasian Clavator grovesii var. jiuquanensis biozone. The occurrence of intermediate populations of C. grovesii var. jiuquanensis and C. grovesii var. corrugatus associated with intermediate populations of C. harrisii var. harrisii, C. harrisii var. reyi, and C. harrisii var. zavialensis, restricts the association to the lower Aptian. These new findings suggest that this area could be important for understanding the evolution of charophytes during the early Aptian. Furthermore, the study provides significant insights into the paleobiogeographic distribution of Lower Cretaceous charophytes, reporting the first record of C. grovesii var. jiuquanensis (previously described only from Eurasia) and C. grovesii var. corrugatus (previously known from the Iberian Peninsula and the United States) in Africa, along with the first report of Echinochara lazarii in the Western Atlas Domain. Similar lower Aptian assemblages had previously been described only in the Algarve Basin (South Portugal), suggesting a strong paleogeographic connection between these areas.