Adaptative strategies of the Toarcian benthic foraminiferal assemblages from the Middle Atlas (Morocco): Palaeoecological implications

•Benthic foraminifera reflect environmental changes during the Toarcian.•Several foraminifera adapted to oxygen restricted conditions changing shape and size.•Proliferation of opportunists under stressful conditions in the bottom during Early Toarcian.•Then foraminifera adapted to shallowing trend during Mid-Late Toarcian oxygenated bottom.•Foraminiferal morphogroups show great potential for reconstructing bottom conditions.