Deer are the most ancient of all the ruminants ( cud chewing animals) and are mostly found in the forests or in the open grasslands. Even though they are part of Bovidae still there are many distinctions which separate them from this class. Nearly all the deer species have large fissure below each eye and the gall bladder is absent in nearly all the deerââ¬â¢s. Unlike other ruminants (cud chewing animals) deer have solid horns and that is its most distinguishing factor. Deer antlers are mass of solid bone and are shed on regular intervals and regrow again. Whereas in all other bovidaeââ¬â¢s the horns are permanent and are not shed.