It is directly based upon, if not coeval with, Shab. 104a, according to which the school-children in the time of Joshua ben Levi (the beginning of the 3rd century) were taught in such mnemonic forms which at the same time suggested moral lessons.
According to some of his coeval biographers, he also made any effort in order to publish an “Historia” about the period between the end of Castro's War and the Treaty of the Pyrenees.
The coeval Toroweap Formation was laid down under marine conditions along the southwest margin of the North American continent and is found in northwest Arizona layered between Coconino Sandstone and the Kaibab Formation.