If you look at literature or stories over time. Even the Bible. Moses went up to get the ten commandments and he returned and his people were worshipping a bull. This was the end of the age of Taurus. The next "Great Year" was the age of Pisces and this is where we see the fish used in symbols. 

I skipped one transitions bull to ram to fish...

So there is your choice of goat!

Here is a bit about the great year. 

https://en.wikipedia.org/wiki/Astrological_age

Nuttall

but what does it mean? I don't mean synchronicity, I mean the line of ages of taurus/Pisces to Aquarius, the circle cross, etc.?