Sponges very diverse.
Many patch reefs. Total thickness of reefal facies exceeds 100 m.
Toomey (1991) suggested outer shelf deposition:
The only outcrops of marine Upper Permian strata in North Africa form an inlier in the Djebel Tebaga area of southern Tunisia. Those outcrops occupy 18km2 (6.9 M2), and comprise the western tip of the Late Permian tethyan seaway. Late Permian marine sediments exposed in southern Tunisia are up to 850m (2789 ft) thick, and grade upward into nonmarine red beds of Permo-Triassic age. Those are unconformably overlapped by flat-lying Jurassic and Cretaceous sediments. Paleogeographically, the Tunisian Permian outcrops represent a biohermal complex situated between a subsurface shale basin to the north, and to the south varied shelf sediments on the margin of the Sahara Shield. Comparison of the Tunisian bioherms to the Permian reef complex of the southwestern United States indicates similarities in biotic composition. Cement fabrics are of major significance at both locations, and are very similar. Both biohermal/reef sequences appear to have been deposited in a shelf-margin paleoenvironment, although the sediments in Tunisia are thin-bedded cyclical or repetitive lithologies associated with overall upward shoaling sequences.