From here:
Quote Originally Posted by doublespy View Post
羊 in Chinese is a generic term for caprids. It can be both. And the Chinese zodiac is the same which does not really specify whether it's sheep or goat. Try googling a picture of say “Chinese zodiac 2015” you'll find all sorts of caprids.
Heh, even when I Google Image 未年 (Year of the Caprid), I get images of both sheep and goats! Also, you'll notice that the Kanji for Caprid in the compound for Year of the Caprid is 未, and not 羊 (hitsuji) or 山羊 (yagi). 未 on its own means "not yet," as in words like:
未来 (mirai) = "future", lit. "(events which have) not yet come (to pass)"
未成年 (miseinen) = "minor" (as in a person under age). lit. "not yet become years (i.e. come of age)"
But in the context of the Lunar Zodiac, 未 refers to the '8/12 heavenly branch,' which is the caprid.

It doesn't surprise me that while 羊 semantically means "sheep," it may also be synonymous with goats or just any kind of caprid. As I mentioned before, while 猿 (saru) semantically means "monkey," it can also be used to generically refer to any kind of non-human primate, thus apes can also be included (which is why 孫悟空 (Son Gokuu) is often portrayed as a tailless ape as well as a tailed monkey. Then there's Dragonball which just gave us tailed apes, but they're aliens, so that's okay. )