I absolutely love this execution of a fantastic concept. It feels like it came out of nowhere too. I've actually had plans on maybe one day taking a shot at the concept art.
My only point of criticism goes to the centerpiece here. I believe the Frost Wyrm skull could be improved a little bit - the texture doesn't fit the "dino" theme well, and is too low resolution. Even if the texture is kept, I believe you could flesh out some of the details more - give it 3D teeth for example.