Why are there two different zodiac symbols for the Capricorn sign?

capricorn is both a goat and a sea goat. I have been wondering the same thing for a while now...however I did find on Wiki that the V like symbol is more from western Astrology while the 7 looking one is more from Hellenistic astrology. hope this helps....
For most people, this is which zodiac sign which is the best lover.