As I said before I have absolutely not a fraction of the knowledge on this thread, but you got me wondering.As there are always layer upon layer of coded information in any relic, preserving and passing on knowledge for posterity,could the representations of the zodiac/ constellation signs ALSO represent the planet they are each assigned ? E.G.Aquarius,(now ruled by Uranus but originally) by Saturn. Pisces the fish (is now ruled by Neptune but once was) ruled by Jupiter, as was and is Sagittarius. Mercury is such a key planet ruling key sign Virgo. As I read this I see echoes again from Zoroastrianism re Mercury. Mercury has the most'eccentric' orbit of all the planets. I'm thinking of the turning boat.There was also a 13th zodiac sign of the Spider, I think around the now allotted sign Taurus ruled by Venus, going into the sign of Gemini which is also also ruled by Mercury.
The Spider is part of Auriga,meaning Charioteer, between Perseus and Gemini in the sky.Identified by Ptolemy and an interesting entry on Wikipedia.
In Astrology the 2000 year Ages go backwards from Pisces, through to Aquarius and so on.Pisces being the end of the Zodiac Cycle.There is always a period where the old age and new age overlap.At present we have Pisces ruling wars, religion and suffering knocking heads with Aquarius ruling technology, electricity and inventions, Pisces rushing to finish it's control and Aquarius can't flourish enough.
I cannot remember why the year was altered from 13 four weekly periods but that is how we lost the Zodiac Spider going from my memory.