By 2,000 BC, the Egyptians and Mesopatamians marked the seasons by the constellations we now call Taurus, Leo, Scorpio and Aquarius. The division of the ecliptic into the zodiacal signs originates in Babylonian ("Chaldean") astronomy in the early to mid 1st millennium BC (likely during Median/"Neo-Babylonian" times).
The signs were named after the nearby constellations at the time of Ptolemy, most of which were named after animals, hence the term zodiac (from Greek zodiakos, "circle of little animals").
- ♈ Aries 0° (vernal equinox)
- ♉ Taurus 30°
- ♊ Gemini 60°
- ♋ Cancer 90° (summer solstice)
- ♌ Leo 120°
- ♍ Virgo 150°
- ♎ Libra 180° (autumnal equinox)
- ♏ Scorpius 210°
- ♐ Sagittarius 240°
- ♑ Capricornus 270° (winter solstice)
- ♒ Aquarius 300°
- ♓ Pisces 330°
