Dinosaur Comics - March 12th, 2010 - awesome fun times!
IMO:
T-Rex: ENTj
Utahraptor: INFj
A semi dual couple. The T-Rex is brash and headstrong, but also articulate and intelligent. The Utahraptor tends to question him, mainly on ethical grounds, and usually ends up influencing him in the last panel (T-Rex in insecure pose).
Dromiceiomimus doesn't have a clearly defined personality, but I'd probably call him ISTp.
Also posting this cause the site is one of those things everybody has to know about.