First evidence of the benthic foraminifera Alveosepta jaccardi from the Oxfordian of the Saharan Atlas (Algeria): Palaeoenvironmental and palaeoecological implications

Microfacies studies conducted on carbonate deposits of the Theniet Et-Temar Formation (Upper Jurassic, Middle Oxfordian) from the Central Saharan Atlas in Algeria revealed low-diversity microfossil assemblages dominated by the large benthic foraminifer Alveosepta jaccardi. The species is an index taxon for the Middle- Upper Oxfordian-Lower Kimmeridgian time interval. It has been recorded previously from Lower Kimmeridgian strata of neighbouring areas. In our study area, a Middle Oxfordian age has been attributed to the foraminifera- bearing deposits based on brachiopod faunas. This constitutes the oldest record of this species from the North African Tethys margin in Algeria. Microfacies analysis suggests a deposition in a shallow, sheltered and moderately eutrophic inner platform environment with low- to medium- energy conditions.