Conversation so far:
What is Mandaeism's relationship with Cosmology?
Mandaean theology is not systematic as there's no one single authoritative account of the creation of the cosmos, but rather a series of several accounts.
What were some of Mandaeism's accounts of the creation of the cosmos?
Mandaean religious texts recall a discrete division between light and darkness. Ptahil, the third emanation, fills the role as the creator of the material world.
What divides the Ginza Rba scriptures?
Ginza Rba is divided into two halves—the Genzā Smālā and the Genzā Yeminā.
Can you elaborate on the division of Ginza Rba scriptures?
Genzā Smālā has colophons that suggest Mandaeism may date to the late Parthian Empire.

Question: Around what time were these theories created?
Self-contained rewrite: Around what time were Mandaeism theories created?