It all goes back to the ancient culture and that is Greece.The signs of the Zodiac have names that can be traced back to events in time.
Let’s start with Aries who in Zeus’s son and is the demigod of war.It is also based on Chrysomallus which was a flying ram that rescued Phrixus and Helle who are the children of the Boeotian king Athamas.
Taurus is falsely claimed to be Zeus disguised as a bull to carried Europa to Crete,Greece;which is how we got the name of Europe.Look it up.
Gemini is the Dioscuri who are Castor and Pollux.Castor and Pollux are the sons of Leda.Leda had two sons from two different fathers.She had Castor with the King of Sparta.She had Pollux with Zeus who lured her in is claimed to have been disguised as a swan.
Cancer is one of the Labours of Zeus’s son Hercules who killed him(a crab a.k.a. cancer) and it was later made added.
Leo is one of the Labours of Zeus’s son Hercules who killed him(a lion a.k.a. leo) and it was later added as a constellation.
Virgo is Demeter the sister of Zeus who had a daughter Persephone who are both part of the Eleusinian mysteries.
Libra is Lustitia or Lady Justice who represents justice.
Scorpio is the scorpion that killed Orion the hunter who was a warrior back in ancient times.
Sagittarius is Chiron the centaur which is a half human/half horse and is a ancient creature.Chiron was considered among the Greeks to be the wisest centaur ever.
Ophiuchus is the serpent wrestler who is Asclepius.He is the son of Apollo who is Zeus’s son.He was taught by Chiron the centaur.He was claimed to have learned to bring people back from the dead which he might have done.
Capricorn is Amalthea who supposedly suckled Zeus back in ancient times.
Aquarius is Ganymede who was kidnapped by Zeus who later poured drinks for Zeus and others.
Pisces is Aphrodite a.k.a. Venus and her son Eros a.k.a. Cupid who were transformed into fish to survive while facing the monster Typhon.
I hope that clears up any confusion that you may have regarding the Zodiac which means Circle.