Arkell.1956.Jurassic..

298 THE MIDDLE EAST
interest in the faunas so far discovered are: (1) The Lower Toarcian assemblage
of Spiriferina with Bouleiceras and other peculiar ammonites;
(2) The Bajocian Ermoceras-Thambites ammonite fauna, previously
known only at Gebel Maghara in Sinai; (3) The NW. European Middle
Bathonian ammonite genera Tulites, Micromphalites and Clydoniceras,
associated with entirely new genera; (4) The presence of the Upper
FIG. 44.—Sketch-map to show the Trans-Erythraean trough and southern Mediterranean,
and occurrences of the peculiar genera Bouleiceras (Lower Toarcian) and Ermoceras
(Upper Bajocian).
Bathonian Eligmus beds with Gryphaea costellata Douville, as in Sinai,
Palestine, Syria and Somaliland; (5) The presence of the Coronatum
Zone of the Middle Callovian, with Erymnoceras and Pachyceras, but no
sign of the more ubiquitous Lower Callovian ammonite faunas.
TITHONIAN ?
Riyadh Group. The group contains thick beds of anhydrite (Hith
Anhydrite), the collapse of which has greatly disturbed the strata. At
http://jurassic.ru/