Yesternight Tim and I were discussing the choices one could have when creating a character. Apart from the general species (longneck, threehorn, swimmer etc.) we came up with the subspecies already mentioned by Tim (e.g. Apatosaurus, Diplodocus, Brachiosaurus in case of longneck) which would be different in appearance but not in abilities. Furthermore different shades of colors (bright, middle, dark shades of green, gray, brown etc.) should enable the player to create an individual character. It would be practicable to make it impossible for two perfect clones to appear in the game. As most of the characters have three main colors there would be many variants if those three could be picked individually. Maybe one could even pick individual eye colors, but I don't know if this can be done.
However there is one feature which we did not mention yesterday which I think should be included. Characters should be male or female which wouldn't make any difference in the abilities but some in the outward appearance. This is where character designers are needed to come up with characters of distinguishable gender (we have had the discussion on how difficult that is to manage in a fanart thread).
I started drawing a chart for longneck characters (always with a side and front view) today, but it may take a long while before it will be finished.