Well, even if I vote for it as a Velociraptor head for consistency's sake, the head really looks that of a T-Rex because of the degree of angle of the jaws and the size of the eyes. (You be the judge)
Velociraptor Head:
T-Rex Head:
Although I think that they can put whatever animal's head in there as long as they are following the theme which is the 'fang', they can even put a shark's head in there and say that it is still consistent with the theme, but IMHO, they should have just stuck with the Velociraptor head because of the T-Rex Gaia Memory. Well, the Japanese have a weird way of thinking sometimes, and not to mention Toei and Bandai's goal to milk as much merchandises as they can from their series, so it can't be helped...