sailor cosmos in the anime appeared at first as chibichibi (like in the manga) and lived with usagi. many say there is no sailor cosmos in the anime, but there is. she appears in the final episode as you see her to the left.
do not tell me i'm wrong, i own the last episode on tape. (thank you vick) i have what she clearly says below:
''sailor moon, i've been looking for you (sailor moon:who are you?). . .someone who can accept me. . .i am a shining star that was once within galaxia,the light of hope. (sailor moon:the light of hope?) please accept my shining life!'' cosmos dissapears and a butterfly flies towards usagi, forming a starseed that gives usagi her starseed back ''please! please light up the galaxy again with the light of hope. . . by using this sword'' a sword appears before usagi:''sword?''
''please defeat galaxia with this sword of sealing.''
(usagi:''but. . .'') ''there's no time to think. . .end the war!''
so now that you know that, what does cosmos mean? well, cosmos in certain terms means universe, and the universe is what cradles the galaxies, so, galaxia is the protector of the galaxies, while cosmos is the protector of the universe. so why isn't she sailor universe? well, cosmos is more astrological, ''universe'' is more of a common word. universe is often confused with galaxy, but a galaxy is only one area, for instance, we are in the milky way galaxy, we are not the only galaxy, but the two are still confused together, so naoko used ''cosmos'' to keep the two apart. they are separate characters in both anime and manga. in the anime, chibichibi is galaxias starseed, but i suppose she is then changed into a being because after galaxia (healed) leaves, chibichibi and endimion appear, so she is now her own being. 
