We have acquired the name "zodiac" from the Greek zodiakos kyklos ("animal circle") beause the layout of the star groups was likened to the shape of a lion, fishes, and so on. But those imaginary shapes and names were actually originated by the Sumerians, who called the twelve zodiacal constellations UL.HE ("shiny herd"):

1. GU.AN.NA ("heavenly bull"), Taurus.
2. MASH.TAB.BA ("twins"), our Gemini.
3. DUB ("pincers," "tongs"), the Crab or Cancer.
4. UR.GULA ("lion"), which we call Leo.
5. AB.SIN ("her father was Sin"), the Maiden, Virgo.
6. ZI.BA.AN.NA ("heavenly fate"), the scales of Libra.
7. GIR.TAB ("which claws and cuts"), Scorpio.
8. PA.BIL ("defender"), the Archer, Sagittarius.
9. SUHUR.MASH ("goat-fish"), Capricorn.
10.GU ("lord of the waters"), the Water Bearer, Aquarius.
11.SIM.MAH ("fishes"), Pisces.
12.KU.MAL ("field dweller"), the Ram, Aries. 

Most scholars consider the Sumerian stress of Taurus as their first constellation as evidence not only of the antiquity of the zodiac--dating to circa 4000 BC--but also as testifying to the time when Sumerian civilization so suddenly began. Professor Jeremias (The Old Testament in the Light of Ancient East) found evidence showing that the Sumerian zodiacal-chronological "point zero" stood precisely between the Bull and the Twins; from this and ohter data he concluded that the zodiac was devised in the Age of Gemini (the Twins)--that is, even before Sumerian civilization began.

A sumerian tablet in the Berlin Museum (VAT.7847) begins the list of zodiacal constellations with that of Leo--taking us back to circa 11,000 BC, when Man had just begun to till the land.

Sitchin 1976:197

But mostly the planets were spoken of in the framework of astronomical texts dealing with the MUL.MUL--a term that kept the scholars guessing. In the absence of a better solution, most scolars have agreed that the term mulmul stood for the Pleiades, a cluster of stars in the zodiacal constellation of Taurus, and the one through which the axis of the spring equinox passed (as viewed from Bablylon) circa 2200 B.C.

Mesopotamian texts often indicated that the Mulmul included seven LU.MASH (seven "wanderers that are familiar"), and the scholars assumed that these were the brightest members of the Pleiades, which can be seen with the naked eye... Sitchin 1976:200