Korn, Klug & Reisdorf, 2000, p.72:

Takhbtit East (19 km west-northwest of Taouz): At this place, the crinoid limestones show a thickness of
6 meters and are overlain by a 15 cm thick bed of black ammonoid packstone that contains mostly fragments of
the Platyclymenia annulata Fauna, preferably Pl. annulata and Prionoceras divisum.  Immediately
following this bed, the Gonioclymenia Limestone isdeveloped, providing evidence for a major sedimentary
gap that occurs at this place.