Jurassic World Poster
(click to enlarge)
https://farm4.staticflickr.com/3949/15539707312_11cddcb626_c.jpg
If they're advanced enough in their cloning technology to engineer a dinosaur, they can add as many fingers or toes or even genitalia as they like, it's not that much of a leap.
True I suppose, but why bother? If you're going to do something like say, create your own evolutionary successor to the T-Rex why wouldn't you stick the original basic template that all tyrannosaurs share, just make it bigger and maybe tweak a few small things to try and make it look scarier but why add a finger?
Trailer?!
... soon.